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What Happened to Global Warming? Scientists Say Just Wait a Bit
Abstract
Climate ChangeThe blogosphere has been having a field day with global warming's apparent decade-long stagnation. But climatologists are finding that although global warming has indeed paused, it is likely to return with a vengeance within a few years.
... Since 1998, the rate of global temperature increase has markedly slowed and even become slightly negative, which has been confirmed by many studies (Kaufmann et al., 2001;Cohen et al., 2012). However, it is still unclear if this slowdown in the rate of temperature increase represents a real WH or is just a temporary slowdown in the temperature increase (Kerr, 2009;Knight et al., 2009;Roberts et al., 2015;Yan et al., 2016;Medhaug et al., 2017). Based on a comparative analysis of global data, it has been confirmed that the WH phenomenon indeed exists, as the temperatures in areas of Eurasia (Kerr, 2009), China (Roberts et al., 2015), the North Atlantic and the extratropical continents in the Northern Hemisphere (Medhaug et al., 2017) have stopped rising or have increased at notably slower rates since 1998. ...
... However, it is still unclear if this slowdown in the rate of temperature increase represents a real WH or is just a temporary slowdown in the temperature increase (Kerr, 2009;Knight et al., 2009;Roberts et al., 2015;Yan et al., 2016;Medhaug et al., 2017). Based on a comparative analysis of global data, it has been confirmed that the WH phenomenon indeed exists, as the temperatures in areas of Eurasia (Kerr, 2009), China (Roberts et al., 2015), the North Atlantic and the extratropical continents in the Northern Hemisphere (Medhaug et al., 2017) have stopped rising or have increased at notably slower rates since 1998. Some researchers have argued that the slowdown in the rate of global temperature increase since 1998 represents a small cooling-related fluctuation or indicates a slowdown of the Earth's warming (Karl et al., 2015) and that the temperature has not truly experienced a hiatus. ...
... The temperature at very few stations rose again after the end of the WH (2012WH ( -2015, and such stations were concentrated in the north. The period from the beginning to the end of the WH was 8-10 years, according to the length of the current data series, and the WH has lasted for 26 years and has not yet ended at some stations, far exceeding 15 years (Kerr, 2009). Owing to the short length of the data series, it is unclear if the warming actually ended based on the resumed temperature rise seen in a small range of areas. ...
The abrupt temperature change (ATC) and warming hiatus (WH) phenomena impact global resources and the environment. However, information on the spatial and temporal variability in the ATC and WH over large regions, long time scales and densely distributed stations is lacking. In the study, based on average minimum, average and average maximum temperatures data from 1951 to 2016 from 622 meteorological stations in China, the spatial and temporal variability in the timing of the ATC and WH events and the characteristics before and after these events were revealed by using the Mann–Kendall test. In most areas of China, an ATC occurred in the three temperature parameters, and the onset of the changes occurred later at lower latitudes. The ATC in the average minimum temperature occurred earlier than that in the average temperature, and the ATC in the average maximum temperature occurred the latest. After the ATC, a WH occurred at most of the stations that experienced an increase in temperature, whereas a cooling hiatus (CH) did not occur at stations that experienced a decrease in temperature. The regions with decreasing temperatures were concentrated in the hilly and plain areas of southern China and in subtropical and tropical monsoon climate zones. The WH of the average temperature occurred earlier than that of the average maximum temperature, which occurred earlier than that of the average minimum temperature. Overall, the WH began later from east to west and was mainly concentrated in approximately 1998 and 2007. Both the ATC and the WH in the Qinghai–Tibet Plateau area showed hysteresis. The ATC to WH period was between three and 27 years, and the earlier the ATC was, the longer was the period. Before the ATC, all three temperature parameters increased slightly. The average minimum temperature rose faster than the average temperature, and the average maximum temperature rose the slowest. Furthermore, the variation became more dramatic from southeast to northwest. After the ATC, the temperatures in most areas increased rapidly, and the rate of temperature increase increased with decreasing latitude. The average maximum temperature decreased in the area east of 100° E and south of 30° N. In this area, the rates of temperature increase for the average minimum and average temperatures were on a par with the rate of decrease in the absolute average maximum temperature, with the rates being three to five times greater than those before the ATC, but without dramatic variations. After the ATC, a CH did not occur at the stations where the temperature had decreased, whereas a WH occurred after a certain period of time at most of the stations where the temperature had increased. Moreover, such occurrences differed with latitude. A comparison of the temperature after the WH with that both before and after the ATC but before the WH revealed that the temperature did not vary dramatically. Eight to 10 years after the WH, the temperatures at a small number of stations in northern China rose again; however, due to the short length of the time series, it is impossible to determine whether the WH had truly ended. The results of the study enrich the findings of climate change research and provide a reference for addressing resource and environmental issues. In the study, based on average minimum, average and average maximum temperatures data from 1951 to 2016 from 622 meteorological stations in China, the spatial and temporal variability of the years of the abrupt temperature change (ATC) and warming hiatus (WH). Distribution of stations in the study area.
... El CO 2 es el gas de efecto invernadero (GEI) que más contribuye al incremento de la temperatura global, por lo que incide directamente en el cambio climático (Kerr 2009). ...
... al. 2009, Lebrija-Trejos et al. 2010, Yepes et al. 2010, Avella-M et al. 2019. El área basal es similar a lo observado en bosques secundarios montanos de Colombia, donde fluctuó entre 5 y 29,7 m 2 .ha -1 en sucesiones de hasta once años y de 25,2 a 35,5 m 2 .ha -1 entre los 25 y 40 años(Yepes et al. 2010). ...
Tropical successions are environments that cover large areas and are of great importance due to their ecological functions and extension. In Ecuador, studies on the carbon storage of these ecosystems are scarce and most of the equations are developed for humid lowland areas. The aim of this research was to generate allometric models for estimation of aerial biomass of secondary montane forests in northwestern Ecuador. A forest inventory was carried out in three secondary forests of 18, 30, and 50 years old approximately. Allometric models were developed using diameter at breast height (DBH) and total height (Ht) as independent variables, and the organic matter and accumulated aerial carbon were estimated. The DAP2Ht combinatorial variable was the best predictor variable according to the adjustment and validation criteria. The model equations showed an R2 greater than 95 %, consequently the variables studied are reliable. It was determined that forests store 36.56, 70.36, and 156.27 Mg.C.ha-1 respectively, where the stem is the component with the highest storage with a range between 65.76 and 73.44%. Both branches and leaves represent between 20.98 - 25, 50% and 5.58 - 8.74% of the total aerial carbon respectively. These models could be applied effectively in ecosystems with similar environmental conditions.
... It is generally agreed in the literature that the measured global mean surface temperature (GMST) had a clear rise of approximately 0.6 K between 1950 (more precisely 1975) and around 2000, coinciding with a rise in atmospheric CO2 level. There were several reports of global warming stopping for the period between 2000 and around 2015 [1][2][3][4][5][6][7][8][9] , whereas the GMST appears to have risen again in recent years. It is also generally agreed that El Niño southern oscillation (ENSO) is one of the largest sources of year-to-year variability, but it is not likely the main cause. ...
... In view of observations reported previously by the author 1,3,6,9 , others 2,4,5,7,8,20,21 , and shown in contrast to that of standard climate models, but is strongly supported and consistent with solid observations presented in this study and previously 1,3,6,8,9,20,21 . ...
Time-series observations of global lower stratospheric temperature (GLST), global land surface air temperature (LSAT), global mean surface temperature (GMST), sea ice extent (SIE) and snow cover extent (SCE), together with observations reported in Paper I, combined with theoretical calculations of GLSTs and GMSTs, have provided strong evidence that ozone depletion and global climate changes are dominantly caused by human-made halogen-containing ozone-depleting substances (ODSs) and greenhouse gases (GHGs) respectively. Both GLST and SCE have become constant since the mid-1990s and GMST/LSAT has reached a peak since the mid-2000s, while regional continued warmings at the Arctic coasts (particularly Russia and Alaska) in winter and spring and at some areas of Antarctica are observed and can be well explained by a sea-ice-loss warming amplification mechanism. The calculated GMSTs by the parameter-free warming theory of halogenated GHGs show an excellent agreement with the observed GMSTs after the natural El Niño southern oscillation (ENSO) and volcanic effects are removed. These results provide a convincing mechanism of global climate change and will make profound changes in our understanding of atmospheric processes. This study also emphasizes the critical importance of continued international efforts in phasing out all anthropogenic halogenated ODSs and GHGs.
... The areas of negative warming trends are colored in black, and the areas of positive trends remain white. The areas of unessential WT trends, i.e., the areas of warming pauses as these have been defined by Kerr [13], are colored in grey. Note that since any global temperature series is finite in its length, the WT pattern is slightly disturbed inside of its initial and final parts. ...
... It is easy to calculate that 13 warming pauses exist near the 10-year wavelet scale within the undisturbed part of the WT pattern and only four pauses exist near the 15-year scale. Thus, Kerr [13] was right: 10-year long warming pauses are common, but 15-year long ones are rare in the climate dynamics. However, the WT pattern in Figure 1, considered as a whole, reveals that the seldom observed 15-year pauses are grouped in pairs, and account, together with shorter pauses in their beginnings and the ends, for two periods of general climatic cooling, which lasted, in total, approximately 30 years each. ...
It is widely accepted to believe that humanity is mainly responsible for the worldwide temperature growth during the period of instrumental meteorological observations. This paper aims to demonstrate that it is not so simple. Using a wavelet analysis on the example of the time series of the global mean near-surface air temperature created at the American National Climate Data Center (NCDC), some complex structures of inter-annual to multidecadal global mean temperature variations were discovered. The origin of which seems to be better attributable to the Chandler wobble in the Earth’s Pole motion, the Luni-Solar nutation, and the solar activity cycles. Each of these external forces is individually known to climatologists. However, it is demonstrated for the first time that responses of the climate system to these external forces in their integrity form a kind of polyphony superimposed on a general warming trend. Certainly, the general warming trend as such remains to be unconsidered. However, its role is not very essential in the timescale of a few decades. Therefore, it is this polyphony that will determine climate evolution in the nearest future, i.e., during the time most important for humanity currently.
... Since the end of the 1990s, the global warming rate has been +0.07 ± 0.07°C per decade, which is much smaller than the rate of 0.18°C per decade from 1979 to 2005. Kerr (2009) reported these studies in science, after which the above phenomenon was called the global warming hiatus. Medhaug et al. (2017) pointed out that the stagnation of global warming mainly refers to the weakened warming or cooling trend of the global average surface temperature from 1998 to 2012. ...
... Medhaug et al. (2017) pointed out that the stagnation of global warming mainly refers to the weakened warming or cooling trend of the global average surface temperature from 1998 to 2012. These studies were reported in science by Kerr (2009) and have since been referred to as global warming stagnation. Medhaug et al. (2017) noted that the global warming hiatus mainly refers to the weak warming or cooling trend of the global average surface temperature from 1998 to 2012. ...
The mechanisms of abrupt seasonal temperature changes and warming (cooling) hiatuses remain unclear. Clarifying how they respond to various influencing factors is critically important to understanding their mechanisms. In this study, the influencing factors to which the abrupt changes in Tav, Tnav, and Txav were most sensitive followed the order of (AGG and CO2) > SR > WS > AMO > PDO > MEI > AO > AP > RH. Seasonal Tav had the greatest sensitivity to all influencing factors, followed by seasonal Tav and lastly by seasonal Txav. An abrupt temperature change occurred when AGG, AMO, or SR increased continuously to a certain value, when PDO was in a positive phase (warm phase) and increased continuously to a certain value, when MEI changed abruptly, when WS and RH continued to decline for a certain time and reached a certain tendency rate, or when AP continued to decline for a certain time and reached a certain value. During the period before and after the warming (cooling) hiatuses, the temperature at most of the stations only had a significant relationship with a few influencing factors, and the hiatuses in seasonal Tav, Tnav, and Txav were overall most sensitive to changes in WS, followed by changes in RH and lastly by changes in AP. The occurrence of warming (cooling) hiatuses was highly consistent with the variation trend of some influencing factors, which to some extent affected the warming (cooling) hiatuses. Abrupt seasonal temperature changes/warming (cooling) hiatuses are the combined effects of multiple influencing factors.
... . 针对全球温度变 化表现出的新特点, 有研究认为 [3] , 这一现象是暂时 的, 全球增暖仍将继续. 也有研究认为 [3] , 过去的 10 [12] . ...
... . 针对全球温度变 化表现出的新特点, 有研究认为 [3] , 这一现象是暂时 的, 全球增暖仍将继续. 也有研究认为 [3] , 过去的 10 [12] . 这两个周期性波动 也出现在中国的干湿气候变化序列中 [17,18] . ...
... Climate warming is one of the most important factors affecting natural ecosystems and socio-economic systems (Jevrejeva et al., 2010;Qin et al., 2014;, such as sea-level rise; ocean acidification; cryosphere retreat; hydrologic cycle disruptions, including water shortages; higher frequency of extreme events, and biodiversity impairment. However, Carter (2006) of James Cook University discovered a stagnation in global warming, termed a global warming hiatus, in 2006, which has caused a fierce debate on its existence and formation (Kerr et al., 2009;Knight et al., 2009;Roberts et al., 2015;Huang et al., 2017). Knight et al. (2009) and Kerr et al. (2009) contrasted global surface temperature changes in 1998-2012 with earlier stages based on global measured temperature data and reanalysis data, which confirming the warming hiatus. ...
... However, Carter (2006) of James Cook University discovered a stagnation in global warming, termed a global warming hiatus, in 2006, which has caused a fierce debate on its existence and formation (Kerr et al., 2009;Knight et al., 2009;Roberts et al., 2015;Huang et al., 2017). Knight et al. (2009) and Kerr et al. (2009) contrasted global surface temperature changes in 1998-2012 with earlier stages based on global measured temperature data and reanalysis data, which confirming the warming hiatus. The IPCC's Fifth Assessment Report also clearly stated that the global warming trend slowed significantly in the period of 1998-2012 compared with the previous 30-60 years, which was about 1/3-1/2 of the warming range from 1951 to 2012. ...
The 1998–2012 global warming hiatus has aroused great public interest over the past several years. Based on the air temperature measurements from 622 meteorological stations in China, the temperature response to the global warming hiatus was analyzed at national and regional scales. We found that air temperature changed −0.221°C/10a during 1998–2012, which was lower than the long-term trend for 1960–1998 by 0.427°C/10a. Therefore, the warming hiatus in China was more pronounced than the global mean. Winter played a dominant role in the nationwide warming hiatus, contributing 74.13%, while summer contributed the least among the four seasons. Furthermore, the warming hiatus was spatial heterogeneous across different climate conditions in China. Comparing the three geographic zones, the monsoon region of eastern China, arid region of northwestern China, and high frigid region of the Tibetan Plateau, there was significant cooling in eastern and northwestern China. In eastern China, which contributed 53.79%, the trend magnitudes were 0.896°C/10a in winter and 0.134°C/10a in summer. In the Tibetan Plateau, air temperature increased by 0.204°C/10a, indicating a lack of a significant warming hiatus. More broadly, the warming hiatus in China may have been associated with the negative phase of PDO and reduction in sunspot numbers and total solar radiation. Finally, although a warming hiatus occurred in China from 1998 to 2012, air temperature rapidly increased after 2012 and will likely to continuously warm in the next few years.
... This slowing down in the warming trend of GMSTs after the late-1990s has been termed a "warming slowdown", "hiatus" or "pause" (Fyfe et al., 2013 and2016;Slingo, 2013;Medhaug et al., 2017). Numerous studies have confirmed this warming hiatus over both global (Johnson et al., 2018;Winslow et al., 2018) and regional scales (Garfinkel et al., 2017;Shen et al., 2018) based on model simulations and observational data records (Easterling and Wehner, 2009;Kerr, 2009;IPCC, 2014;England et al., 2014). Yet, some studies have argued that there has been no global warming hiatus since 1998 (Karl et al., 2015;Rajaratnam et al., 2015;Huang et al., 2017a). ...
The recent hiatus in global warming has attracted significant attention, yet whether it is a widespread global and/or regional phenomenon remains controversial. Here, we investigate the response of extreme temperature changes since 1961 across China’s cold regions (CCR): Tibetan determine the spatiotemporal characteristics of extreme temperature changes across these cold regions using Mann-Kendall and wavelet transform coherence (WTC) analyses of data from 196 meteorological stations from 1961 to 2018. We further investigate the teleconnection between extreme temperatures and large-scale ocean-atmosphere circulation to determine the potential synoptic scale causes of the observed changes. The results revealed a significant warming slowdown in all extreme temperature indices across CCR from 1998 to 2018. In addition, extreme temperature indices in northwest cold region (NWC) and north cold region (NC) reveal a clear winter warming slowdown and even a significant cooling trend, yet only the cold index in Tibetan Platean cold region (TPC) shows a warming hiatus. We conclude that the warming hiatus observed across these regions is primarily driven by extreme temperature index changes in winter. We also find that phase variations in the Atlantic Multi-decadal Oscillation (AMO) and Arctic Oscillation (AO) critically impact on the observed warming hiatus, but the specific atmospheric mechanisms are elusive and warrant further analysis and investigation.
... In the widely used ND-GAIN index (2017), Bangladesh ranks 160 out of 181 countries for climate vulnerability. Many study had found warming trends throughout the world (e.g., Jones and Moberg 2003;Solomon et al. 2007;Kerr 2009;Abbasnia et al. 2016;Abbasnia and Toros 2018a, b). There had been a strong warming in the warm period compared to the temperatures of the annual and cold period (Toros, 2012). ...
Extreme climate events have a great impact on the agriculture-based economy like Bangladesh. This study is conducted mainly to gain insight on the overall condition of extreme air temperature of suitable potato growing area in Bangladesh and the effects of some climate extreme indices on potato yield. The result of trend analysis of extreme climate indices indicated that the monthly maximum value daily minimum temperature has continued to increase. While the monthly minimum value of both minimum and maximum temperature has continued to decrease. It is not possible to identify any specific trend for both monthly maximum value of daily maximum temperature. And for precipitation variable, monthly maximum 1-day precipitation also does not follow any particular pattern. Investigating the effects of these extreme indices, it is found that the monthly maximum of daily maximum temperature and monthly maximum of daily minimum temperature has a significant positive impact on potato yield. And other three extreme indicators have negative effects. These positive factors are much more significant on potato yield than those negative factors. Positive factors follows positive trend and negative factors follows negative trend or does not follow any trend at all.
... Since the beginning of this century, several recent studies have shown that there was an insignificant global surface temperature warming trend since 1998, and they proposed the idea of global warming stagnation [35][36][37]. The IPCC's Fifth Assessment Report makes a similar argument [38]. ...
In this study, the instability of extreme temperatures is defined as the degree of perturbation of the spatial and temporal distribution of extreme temperatures, which is to show the uncertainty of the intensity and occurrence of extreme temperatures in China. Based on identifying the extreme temperatures and by analyzing their variability, we refer to the entropy value in the entropy weight method to study the instability of extreme temperatures. The results show that TXx (annual maximum value of daily maximum temperature) and TNn (annual minimum value of daily minimum temperature) in China increased at 0.18 °C/10 year and 0.52 °C/10 year, respectively, from 1966 to 2015. The interannual data of TXx’ occurrence (CTXx) and TNn’ occurrence (CTNn), which are used to identify the timing of extreme temperatures, advance at 0.538 d/10 year and 1.02 d/10 year, respectively. In summary, extreme low-temperature changes are more sensitive to global warming. The results of extreme temperature instability show that the relative instability region of TXx is located in the middle and lower reaches of the Yangtze River basin, and the relative instability region of TNn is concentrated in the Yangtze River, Yellow River, Langtang River source area and parts of Tibet. The relative instability region of CTXx instability is distributed between 105° E and 120° E south of the 30° N latitude line, while the distribution of CTNn instability region is more scattered; the TXx’s instability intensity is higher than TNn’s, and CTXx’s instability intensity is higher than CTNn’s. We further investigate the factors affecting extreme climate instability. We also find that the increase in mean temperature and the change in the intensity of the El Niño phenomenon has significant effects on extreme temperature instability.
... Si bien el IPCC en su quinto informe reitera de manera general la problematización También se argumenta que en la década de los años noventa y a comienzos del presente siglo más que calentamiento, se produjo cierto enfriamiento (Kerr, 2009, Knight et al. 2009, Wang et al, 2010, con lo cual la posibilidad de que efectivamente haya habido una manipulación deliberada de los registros de temperaturas por parte de la Universidad East Anglia, se pone de nuevo sobre el tapete. ...
Se estudió el desarrollo de las investigaciones sobre cambio climático y agricultura en Venezuela durante el período 1989-2019 (30 años), develando algunas implicaciones estratégicas que permitieron identificar necesidades de investigación en términos de requerimientos nacionales de seguridad y soberanía alimentaria, considerando la situación actual y posibles escenarios futuros en el contexto de las relaciones internacionales de tipo geopolítico del país.
Se asumió que la ciencia del cambio climático, al menos en lo que se refiere a sus propuestas de solución a la problemática que estudia, está influenciada por posturas político-ideológicas en el estamento académico (ciencia no neutra). Este supuesto fue verificado para el caso venezolano al identificarse la existencia de dos grupos diferenciados de acuerdo a si promueven soluciones al problema del cambio climático en el país sustentadas en los conceptos de Economía Verde (capitalista), Seguridad Alimentaria y propuestas de aplicación de mecanismos REDD+ (que incluyen mercados de bonos de carbono), en contraste con otro grupo (hasta ahora minoritario) de más reciente conformación, que basa sus propuestas de solución en los conceptos de Ecosocialismo y Soberanía Alimentaria, y rechazan los mecanismos REDD+ y en general el mercado de bonos de carbono.
Una síntesis del método aplicado es la siguiente: Inventario y análisis preliminar de presentaciones públicas de resultados de investigación en el período de 30 años analizado, la mayoría obtenida en Internet (investigación documental). Identificación de cuatro etapas en las investigaciones sobre cambio climático y agricultura en Venezuela: la primera de 1989 a 1996 (“Etapa Fundacional”), la segunda entre 1997 y 2005 que culmina con la publicación de la Primera Comunicación Nacional sobre Cambios Climáticos; la tercera de 2006 a 2018 (de popularización de la ciencia del cambio climático en Venezuela), y, por último, una cuarta etapa, iniciada a finales del año 2019 con el desarrollo del III Simposio Nacional sobre Cambio Climático en Venezuela, cuyo tema central fue la relación Cambio Climático-Seguridad Alimentaria.
Las tres primeras etapas fueron estudiadas con mayor detalle, abordando los siguientes aspectos: a) Principales temas investigados, b) Conformación de grupos de investigación y c) Análisis de discursos como expresión de procesos de legitimación del conocimiento científico, para evidenciar relaciones de poder. A nivel más general se identificaron los fundamentos onto-epistemológicos (dimensión filosófica), valores (dimensión axiológica) y enfoques de planificación (dimensión prospectiva) de la actividad científica estudiada.
Se estima que el enfoque de investigación de la tesis doctoral es útil para promover posteriores comparaciones entre países, en cuanto a las implicaciones estratégicas del desarrollo de la ciencia del cambio climático, facilitando la identificación de agendas regionales de investigación.
PALABRAS CLAVES: Ciencia del Cambio Climático-Agricultura, Contexto de Relaciones Internacionales, Geopolítica y Necesidades de Seguridad y Soberanía Alimentaria, Influencias Político-Ideológicas, Requerimientos de Investigación.
... The global warming trend, characterized by global mean surface temperature (GMST), exhibited a slowdown between two large El Niño events in 1997/98 and 2015/16 [4][5][6][7][8][9][10]. The Intergovernmental Panel on Climate Change's Fifth Assessment Report states that there was a significant reduction in GMST over the 15 years from 1998 to 2012 compared with the 60 years from 1951 to 2012 [11]. ...
It has been reported that global warming results in the increase of globally averaged wave heights. What happened to the global-averaged wave heights during the global warming slowdown period (1999–2013)? Using reanalysis products, together with remote sensing and in situ observational data, it was found that the temporal variation pattern of the globally averaged wave heights was similar to the slowdown trend in the increase in global mean surface temperature during the same period. The analysis of the spatial distribution of trends in wave height variation revealed different rates in global oceans: a downward trend in the northeastern Pacific and southern Indian Ocean, and an upward trend in other regions. The decomposition of waves into swells and wind waves demonstrates that swells dominate global wave height variations, which indicates that local sea surface winds indirectly affect the slowdown in the rate of wave height growth.
... And from the mid-1990s to the early 2010s, the ''consistent cooling'' pattern dominates the winter temperature over mid-and high-latitude Eurasia. This pattern just corresponds to the ''global warming hiatus'' (Kerr 2009;Easterling and Wehner 2009;Medhaug et al. 2017). It is FIG. ...
It is argued that the occurrence of cold events decreases under the background of global warming. However, from the mid-1990s to the early 2010s northern China experienced a period of increasing occurrence of low temperature extremes (LTE). Factors responsible for this increase of LTE are investigated in this analysis. The results show that the interdecadal variation of the winter mean temperature over the middle and high latitude Eurasia acts as an important thermal background. It is characterized by such two dominant modes as the “consistent cooling” pattern and the “Warm high latitude Eurasia and cold middle latitude Eurasia” pattern from the mid-1990s to the early 2010s. And the two patterns jointly provide a cooling background for the increase of LTE in northern China. Meanwhile, though the interdecadal variation of Arctic oscillation (AO), Ural blocking (UB) and Siberian high (SH) are all highly correlated to the occurrence of LTE in northern China, the AO is found to play a dominant role. On one hand, the AO affects directly the occurrence of LTE for its dynamic structure; on the other hand, it takes an indirect effect by affecting the intensity of Ural blocking (UB) and Siberian high (SH). Further analyses show that, the winter temperature over the middle and high latitude Eurasia has a close relationship with the AO, but they are believed to be the independent influential factors of the increase of LTE in northern China from the mid-1990s to the early 2010s.
... 全球气候变化是一个复杂的科学问题，不但需考虑地球系统内部的变化和相互作用，而 且需考虑物理与生物化学等许多过程，包括自然因子、人类活动等 [1] 。虽然，近百年来全球 气候变暖是一个不争的事实，但近十几年全球气候变暖趋势出现明显减缓 [2][3][4] 。IPCC 第五次 评估报告 (AR5) 第一工作组科学报告 [5] 也称， 近 10 多年观测的平均温度落在气候模拟 5%～ 95%置信区间之外，并认为 1998 年以来的气候变暖减缓可能是由于近几年低太阳活动、气 候内部变率(如 ENSO)和模式响应误差的联合作用造成。我国的温度变化既有与全球地面 温度相一致的部分，也有其自身特点，因此，有必要重点针对我国近百年气温变化原因进行 研究。 气候变化归因检测是气候变化研究的核心问题之一。它是以某种程度的显著性水平，建 立有关因子变量与气候变量之间的因果关系的过程 [6] 。近年来，气候变化检测和归因的研 究有了很大进展。从数学原理上发展了检测、归因技术，还发展了针对气候系统特点的检测 方法，以期寻找气候变化的指纹，格兰杰因果检验(Granger causality test)就是一种较新的 归因检测方法 [7][8] ，本文将利用这种方法进行因果关系的检验。 太阳活动和火山活动是影响气候系统的两个重要的自然因子。 太阳作为离地球最近的恒 星，向地球提供着光和热，是地球气候系统最基本的能量源，其长期(万年以上)变化对地 球气候的形成和演变有着重要影响，这已达成广泛共识，但在百年和十年这样相对较短的时 间尺度上，对气候的影响，尤其是对近 100 年来温度的影响和贡献，却存在较大争议 [9] 。另 外，火山活动也会对气候变化产生影响，但其对近百年中国气温的影响和贡献有多大，是尚 待解决的问题。关于人类活动对气候变化的影响，已经有了很多研究 [6] ，IPCC 五次评估报 告都称，人类活动是全球气温上升的主要原因。但是，最近的一些研究表明，天文(如太阳 活动)与地球因子(如火山活动、地球自转变化)对近百年全球气温和降水也有重要影响， 不能忽略，其 影响有可能通过气候系统响应的非线性过程而被放大 [10][11] 。那么对于近百年中 国的气温变化，天文因子、地球因子和人类活动哪个是最重要的因子？信度如何呢？本文将 利用新的因果检验方法--Granger 因果分析法进行检测。 [7] ， 而且，Pearson相关系数本身也存在很大的局限性 [14] 。这种情况下，需要采用Granger因果检 验来检测它们之间的因果关系。 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 ...
首先分析了1880年以来中国年平均气温（TC）的演变特征，发现TC在1980s之前上升趋势并不明显，而是具有准50年左右的振荡周期，但在1980s之后，出现较快速的上升，这滞后于二氧化碳约20年。然后，重点采用格兰杰（Granger）因果检验法，对我国近130年地面气温变化与自然因子（太阳活动和火山活动）和人类活动（CO2）的关系进行了归因分析，所得结果如下：（1）太阳活动不是TC变化的Granger原因；（2）火山活动可能是近百年TC变化的Granger原因之一，但其最优滞后期是14年；（3）CO2的变化可能也是近百年TC变化的Granger原因，它也在年代际尺度上起作用，最优滞后期是22年，这解释了为什么中国气温上升滞后于CO2约20年。
... Specifically, the transient "slowdown" in the warming trend itself could have played an important role in driving reduced epidemics in the background of existing control efforts and before their enhancement. At a global scale, this slowdown was initially termed the "global warming hiatus" on the basis of a presumed lack of an increase in Global Mean Surface Temperature (GMST) over the period from 1998 to 2005 (in the HadCRUT3 data set 12,13 ). It was itself the subject of controversy and debate given its wide implications [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] . ...
A counterargument to the importance of climate change for malaria transmission has been that regions where an effect of warmer temperatures is expected, have experienced a marked decrease in seasonal epidemic size since the turn of the new century. This decline has been observed in the densely populated highlands of East Africa at the center of the earlier debate on causes of the pronounced increase in epidemic size from the 1970s to the 1990s. The turnaround of the incidence trend around 2000 is documented here with an extensive temporal record for malaria cases for both Plasmodium falciparum and Plasmodium vivax in an Ethiopian highland. With statistical analyses and a process-based transmission model, we show that this decline was driven by the transient slowdown in global warming and associated changes in climate variability, especially ENSO. Decadal changes in temperature and concurrent climate variability facilitated rather than opposed the effect of interventions.
... The transformation of EHT-STCs in 1999 may be related to the "warming hiatus." In earlier studies, some scholars have put forward the concept of "warming hiatus" and confirm its existence (Du et al., 2018;Kerr, 2009;Knight et al., 2009). The fifth assessment report of IPCC (2014) also clearly points out that the linear warming trend of global surface temperature in 1998-2012 is higher than that in 1951-1998 significantly. ...
Abstract Extreme high temperature (EHT) events have caused serious impact on society. In previous research, EHT indices seldom consider spatial aggregation. To conduct the comprehensive evaluation, the global EHT days from 1979 to 2017 have been evaluated in terms of high temperature duration, accumulative temperature intensities and magnitude of spatial aggregation based on ERA‐Interim 2 m air temperature data set. In addition, abnormal warming of polar and ocean surfaces has rarely been addressed in global‐scale studies. To address this deficiency, the indices of EHT days are normalized by maximum in history for each location. To solve the time discontinuity problem on EHT spatiotemporal distribution in previous studies, we utilized spatiotemporal scan statistics to detect EHT spatiotemporal clusters (EHT‐STCs), and clusters correspond to a certain spatiotemporal extent where the EHT events are aggregated. This method actualizes time‐continuous and spatiotemporal integral detection. The results show the following: 1. There are apparent changes in EHT‐STC spatial distribution after 1999, so 1999 can be recognized as the critical time node of EHT‐STC spatial transformation. 2. After 1999, the EHT‐STC number gradually increased, and the duration and spatial coverage of EHT‐STC gradually expanded. Overall, EHT‐STCs display a significant northward migration, with an average northward movement of 7.03° for each transition from 1979 to 2017. 3. There are differences in the extremity and transformation process in different regions. EHT‐STCs in Antarctica are concentrated before 1992, with the strongest EHT extremity; EHT‐STCs in the Arctic and middle‐low latitude continents are concentrated after 2010 and 1999 respectively, both with a strong EHT extremity. There is a similar EHT‐STC number in the middle‐low latitude ocean before and after 1999 with the weakest extremity. These results contribute to determining EHT causes and future trends in global climate change.
... It is the fact that the recent temperature rising rate has become much smaller (0.1-0.2° C) during the last two decades than their prediction 0.5°-1.0° C), in spite of the fact that the amount of carbon dioxide is still rapidly increasing (cf., Kerr, 2009). They dismiss also the observed fact that the temperature decreased by 0.1° C from 1945 to 1975 in spite of the fact that the amount of carbon dioxide in the atmosphere was rapidly increasing at that time. ...
In any scientific field, there is always a possibility, in which a particular theory dominates for many years. In this paper, the theory of magnetic reconnection in solar physics and auroral physics is reviewed as an example. It has prevailed for more than a half century in both fields as the “only one” without a concrete progress in understanding the source of energy for solar flares and auroral activities. This unusual situation is analyzed why and how it occurred. Since such a situation could occur in any scientific field, it may be useful to analyze how this situation happened. Actually, it is pointed out that a study of global warming may also be in a similar situation.
... Previous studies showed that the effect of solar activity on modern climate change could not be ignored (Gray et al., 2010). Some scientists proposed that the low solar activity in recent solar cycles might be the main reason for the slow down of global warming since 1998 (Kerr, 2009;Knight et al., 2009;Fyfe et al., 2013;Curry, 2014). ...
The impact of solar activity on climate system is spatiotemporally selective and usually more significant on the regional scale. Using statistical methods and solar radio flux (SRF) data, this paper investigates the impact of the solar 11-yr cycle on regional climate of Northeast Asia in recent decades. Significant differences in winter temperature, precipitation, and the atmospheric circulation over Northeast Asia are found between peak and valley solar activity years. In peak years, temperature is higher over vast areas of the Eurasian continent in middle and high latitudes, and prone to producing anomalous high pressure there. Northeast Asia is located to the south of the anomalous high pressure, where the easterlies prevail and transport moisture from the western Pacific Ocean to the inland of East Asia and intensify precipitation there. In valley years, temperature is lower over the Eurasian continent and northern Pacific Ocean in middle and high latitudes, and there maintain anomalous low pressure systems in the two regions. Over the Northeast Asian continent, north winds prevail, which transport cold and dry air mass from the high latitude to Northeast Asia and reduce precipitation there. The correlation coefficient of winter precipitation in Northeast China and SRF reaches 0.4, and is statistically significant at the 99% confidence level based on the Student’s t-test. The latent heat flux anomalies over the Pacific Ocean caused by solar cycle could explain the spatial pattern of abnormal winter precipitation of China, suggesting that the solar activity may change the climate of Northeast Asia through air-sea interaction.
... 基于遥感和地面观测数据的分 析表明, 在我国华南地区城市热岛效应对城市和区 域温度有着显著的影响 [38] . 在美国, Goodridge [39] [43] . 然而, 根据 GISS 和 NCDC 温度 序列的模拟结果表明, 全球近 10 年温度变化依然呈 明显上升趋势 [25,44] 火山活动也是重要的自然因素之一, 火山喷发 产生的火山灰和气体通过影响大气的辐射传输而降 低地球平均气温 [70,71] . ...
... 然而, 大气中 二氧化碳(CO 2 )浓度最近 10 年仍继续在增加, 甚至比 20 世纪最后 10 年的增长还快. 于是, 有评论提出"全 球变暖中发生了什么 [4] "、"近 10 年全球变暖停止了 吗 [5] ". [7] . 年 分辨率(1850~1978 年)的大气 CO 2 浓度序列取自 3 条 冰芯的分析 [8] . ...
... per decade, which was twice the warming rate from 1880 to 2015 (Intergovernmental Panel on Climate Change, 2013). Since the end of the 1990s, a so-called "warming hiatus" phenomenon was observed at different locations around the world (Kerr, 2009;Knight et al., 2009;Trenberth & Fasullo, 2013). The phenomenon itself and its underlying mechanisms have been widely discussed by the scientific community (Easterling & Wehner, 2009;Meehl et al., 2011;Kosaka & Xie, 2013;Xie, 2016). ...
The Tibetan Plateau (TP) is an ecologically fragile region that is sensitive to climate change. In
the context of global climate change, the climate change trends of the TP and the vegetation dynamic
response need to be investigated. Based on in situ meteorological data, Satellite Pour l'Observation de la
Terre vegetation data, and Moderate Resolution Imaging Spectroradiometer land cover data, a
comprehensive analysis was conducted to determine the trends of climate parameters in the TP region at
different time scales (long term: 1960–2014; midterm: 1980–2014; short term 1999–2014). A consistent
warming trend was observed for different temporal scales, while a warming slowdown was identified during
1999 and 2014. The warming rate was also shown to be much higher in the high‐altitude regions (>4,000 m),
especially at midterm and short‐term time scales. A new cloud‐free time series of vegetation index data
sets was reconstructed, and the vegetation density showed a general increasing trend along with a warming
trend in the TP. The regions showing significant increases accounted for 7.63% of the total Tibetan territory.
The major significant greening trend of the TP was mainly caused by climate factors. The reforestation
projects may have played a minor role in the vegetation greening in specific regions of the TP. In addition,
various vegetation types showed markedly different responses to climate changes. The grassland in semiarid
regions, which accounted for 41.9% of the territory of the TP, was identified to be very sensitive to
variations in both temperature and precipitation.
... El Dióxido de Carbono (CO 2 ) es el principal gas de efecto invernadero y el incremento de sus concentraciones está relacionado con el aumento de la temperatura a nivel global (Knee 2009); por lo que uno de los servicios ecosistémicos más importantes que actualmente ofrecen los bosques tropicales es la captura y almacenamiento del mismo (Wangming et al. 2014). La captura y almacenamiento de CO 2 depende, entre otros aspectos, de las características funcionales de las hojas que determinan la capacidad que tienen estas de interceptar la radiación fotosintéticamente activa (RFA) (Warnock et al. 2006). ...
Los cambios en los rasgos funcionales relacionados con el secuestro de carbono durante la sucesión secundaria del Bosque Seco Tropical (bs-T) en Colombia son poco conocidos. Aquí analizamos cómo varía el secuestro de carbono a lo largo de tres etapas sucesionales: pastizales abandonados, arbustales y bosques secundarios; siguiendo un enfoque basado en rasgos a nivel de especie y comunidad. Medimos siete rasgos funcionales en 41 especies leñosas. Identificamos cuatro tipos funcionales de plantas (TFPs) relacionados con estrategias conservativas y adquisitivas. Tanto el área basal como la abundancia relativa de los TFPs adquisitivos disminuyeron a lo largo de las etapas de sucesión. Por el contrario, los patrones de cambio para los TFPs conservativos fueron menos consistentes. La Media Ponderada de la Comunidad (MPC) del área foliar, contenido foliar de materia seca, densidad de madera y altura máxima fueron significativamente mayores en los bosques secundarios respecto a los estados sucesionales más tempranos. Estos hallazgos ayudan a ampliar la comprensión del secuestro de carbono durante la sucesión del bs-T.
... In particular, the number of warm days' extremes has been globally reported to increase since 1950 (IPCC 2013). Also in the regional scale, the warming trends have been revealed for different parts of the world (e.g., Solomon et al. 2007;Kerr 2009;Simolo et al. 2014;Abbasnia and Toros 2018). ...
This study aimed to analyze warm-days changes extracted from daily maximum temperature time-series of 71 stations in Turkey during 1961–2016. First, the trend analysis of warm-days events indicated that the annual count of warm-days occurrences has been significance rising by a rate of 1.4 days per decade over more than 90 percent of the studied stations. Thus, there are consistent patterns in daily warming throughout the study area. The spatial maps showed that the lowest frequency in the minimum annual number of warm-days occurred in western areas by a total number of 21 days and its highest occurred in the eastern area by a total number of 35 days. Moreover, the highest frequency in the mean and minimum annual count of warm-days observed in the northwestern lowlands and their frequency has decreased toward the eastern mountainous. Also, the highest range of differences between the annual count of maximum and minimum values has happened in the eastern regions which are characterized by high elevation and the lower existence of atmospheric humidity. Therefore, a higher moisture content of the atmosphere in lowland coastal stations favors severe warm-days and the increased risk of human health.
... It observed that since 1950, the number of warm days and nights has increased and the number of cold days and nights has decreased (IPCC 2013). In this subject, many researchers found warming trends in surface temperature over the world, but different trends and intensities found throughout the world (e.g., Jones and Moberg 2003;Solomon et al. 2007;Kerr 2009;Abbasnia et al. 2016;Abbasnia and Toros 2018a, b). There are numerous regional and national studies of recent trends and variability in monthly climate globally (e.g., Fauchereau et al. 2003;Hulme et al. 2001;Zhang et al. 2005;New et al. 2006;Caloiero 2017). ...
Impacts of extreme weather events are relevant for regional economies and in particular societies. In this study, four temperature indices analyzed from 15 coastal weather stations during the period of 1961 to 2016. Observation records indicate that the diurnal temperature range has decreased in the last decades because of changes in the lower difference between the minimum and maximum temperatures. All of the studied meteorological stations in coastal regions have shown a negative trend in the cold spell duration and a positive trend in the warm spell duration. The trend analysis has shown a greater increase in the warm spell duration for lower latitude as well as a greater decrease in the cold spell duration for higher latitude over the analyzed period. Because of this behavior, these stations categorized into two large groups. The southern coastal region is somewhat wet and warm climate, this caused the diurnal temperature range has not been much enough for the agricultural production process which need enough differences between daytime base maximum and nighttime base minimum of the temperatures. As a result, the growth season length has increased by one day on the southern coastal region compared to the northern coastal region over Turkey during the last decades.
... Furthermore, we find that both T max and T min consistently showed a warming slowdown from 1998 (2000), which is also in agreement with the recently reported regional and global warming hiatus phenomenon (e.g. Sun et al. 2017b, c;Kerr 2009;Fyfe and Gillett 2014;Li et al. 2015). Figure 2c shows the global and hemispheric DTR anomaly series. ...
Previous observational analyses show that the land-surface diurnal temperature range (DTR) has decreased in the past 6 decades worldwide. Based on a newly developed China Meteorological Administration–Land Surface Air Temperature (CMA-LSAT) dataset, we analyzed the DTR changes between 1901 and 2014. Results indicate that the global land surface DTR significantly decreased at a rate of −0.036 °C/decade over the 1901–2014 period, mainly due to the large decrease in DTR from 1951 to 2014. For the first half of the twentieth century, most grid boxes (spatial resolution 5° × 5°) show a positive DTR trend, with the positive trends of 32.4% grid boxes being statistically significant, leading to a large and significant increase of 0.048 °C/decade in DTR. However, a dramatic reversal in DTR change occurred in early 1950s, with most parts of global lands exhibiting a shift from increasing to decreasing trends. The global land average DTR decrease during 1951–2014 was −0.054 °C/decade, with 45.0% grid boxes showing significant negative trends. The reverse phenomenon is more obvious in the Northern Hemisphere than that in the Southern Hemisphere. For the periods 1979–2014 and 1998–2014, the decreasing trends in DTR mainly occur in the Northern Hemisphere. The DTR in the Southern Hemisphere experienced much larger increases during the two recent periods than during the period 1951–2014. Asia, Eastern North America, and Australia exhibited widespread decreases in DTR, although the trend pattern for global DTR is generally mixed during 1979–2014 and 1998–2014. There is a good negative correlation between DTR and precipitation in the Northern Hemisphere from 1901 to 2014, with a correlation coefficient of −0.61. The change in precipitation and number of volcanic eruptions, and the “early brightening” of Europe (Stockholm) all benefit the increase of DTR at global and regional scales in the first half of the twentieth century.
... Instead of using 7 separate files, we used the weighted averages of the results as given in De Jager JH et al. 18 The temperature file that we use here consists of the Northern Hemisphere ground temperature data from Moberg et al. 19 extended with data. [20][21][22][23][24] Henceforth, for shortness, we will call this data set the Moberg-Brohan file, with the symbol Earth T ∆ . ...
The emphasis of this study is on the solar aspects of the relation between the average terrestrial Northern Hemisphere ground temperature ΔT_ Earth and the total magnetic fluxes of both the equatorial and the polar fields of the sun, characterized by their proxies, viz. the maximum value per Schwabe cycle of the Group Sunspot Number (Gn_max) and the minimum value of the global antipodal magnetic amplitude activity index aa (aa_min). The former is known for the period 1610 (beginning of systematic sunspot observations) till present and the latter from 1844 (first aa determinations) till present. In order to eliminate the effects of short–term, mainly non–solar variations such as volcanos, el Niño, while also not putting too much emphasis on the Schwabe cycle, the variables are smoothed over 18 years.
The increasingly strong ‘global warming’ (commonly called the modern temperature increase) is statistically significant after around 1915. We estimate that the variations of the terrestrial temperature between 1844 and 1910 are 43% due to those in the solar equatorial magnetic fields and 32 % due to those in the polar fields, while the remaining 25% has another (non–solar?) origin. We expect that the period of solar activity that has recently started will be of the Regular type during the present millennium.
... Temperature and precipitation parameters are some of the most important issues related to climate change and the extreme events that affect our lives. There has been a growing awareness about extreme events in the last two decades, and many researchers found warming trends in surface temperatures around the world, although the magnitude of those changes has not been uniform (see, for example, Jones and Moberg 2003;Solomon et al. 2007;Kerr 2009;Abbasnia et al. 2016). Recent data have shown that the global average temperature has increased by 0.85°C over the last century (IPCC 2013). ...
This study aimed to analyze extreme temperature and precipitation indices at seven stations in the Marmara Region of Turkey for the period 1961–2016. The trend of temperature indices showed that the warm-spell duration and the numbers of summer days, tropical nights, warm nights, and warm days have increased, while the cold-spell duration and number of ice days, cool nights, and cool days have decreased across the Marmara Region. Also, the diurnal temperature range has slightly increased at most of the stations. A majority of stations have shown significant warming trends for warm days and warm nights throughout the study area, whereas warm extremes and night-time based temperature indices have shown stronger trends compared to cold extremes and day-time indices. The analysis of precipitation indices has mostly shown increasing trends in consecutive dry days and increasing trends in annual rainfall, rainfall intensity for inland and urban stations, especially for stations in Sariyer and Edirne, which are affected by a fast rate of urbanization. Overall, a large proportion of study stations has experienced an increase in annual precipitation and heavy precipitation events, although there was a low percentage of results that was significant. Therefore, it is expected that the rainfall events will tend to become shorter and more intense, the occurrence of temperature extremes will become more pronounced in favor of hotter events, and there will be an increase in the atmospheric moisture content over the Marmara Region. This provides regional evidence for the importance of ongoing research on climate change.
... An important factor to consider is the rise in sea level that is projected to accompany increased global temperatures associated with climate change, and the effects this will have on coastal dry forest habitat. One anticipated outcome of rising seas and mutable coastal morphology is that mangroves will successfully accrete peat and migrate inland (where human infrastructure is not a barrier), thereby encroaching on dry forest habitat (McKee et al. 2007;Kerr 2009;Blunden et al. 2011;McKee 2011). ...
During this season the Blake-Nuttall fund has provided continuing support for (1) a recently established academic program in ornithology and avian conservation (the only such effort in Puerto Rico); (2) employ mist netting, color banding, and stable isotopic analysis for multiple species and light-level geolocator deployment for Northern Waterthrushes (Parkesia noveboracensis) to establish links between breeding and wintering populations of migratory songbirds that nest in North America and winter, or stop over in Puerto Rico; (3) document patterns of molt in Neotropical Migrants; and, (4) establish a long-term monitoring program for migratory and year-round resident species of terrestrial birds that utilize secondary coastal dry forest and mangroves in and around the area of the Jobos Bay National Estuarine Research Reserve (JBNERR). The funds have provided continuing support for undergraduate, and graduate student research focusing on long-distance migratory and interhabitat movement, habitat quality, and social structure of migrants and nesting residents, and promote and enhance the academic and professional development of ornithology and citizen science in Puerto Rico. This project provides the first implementation of archival light-level geolocator technology by a Puerto Rican institution to study the migratory connectivity of Neotropical migratory birds in Puerto Rico and will complement existing information derived from banding returns and stable isotope analyses. This project allows us to demonstrate new technology to students and the public and help establish the specific intercontinental migratory connectivity of specific populations of migratory birds, especially the Northern Waterthrush, that breed in North America and pass the winter in Puerto Rico and/or South America. We deployed 40 light-level geolocators on Northern Waterthrushes at Jobos Bay in Salinas, Puerto Rico.
... An important factor to consider is the rise in sea level that is projected to accompany increased global temperatures associated with climate change, and the effects this will have on coastal dry forest habitat. One anticipated outcome of rising seas and mutable coastal morphology is that mangroves will successfully accrete peat and migrate inland (where human infrastructure is not a barrier), thereby encroaching on dry forest habitat (McKee et al. 2007;Kerr 2009;Blunden et al. 2011;McKee 2011). Management and conservation require knowledge on the timing and pattern of migration, details on demography and habitat use patterns on the wintering sites, and the awareness of, and will to conserve migratory species at their nesting, stop-over and wintering sites. ...
The effective conservation of long-distance migratory birds requires the identification and protection of the birds, nesting habitat as well as their stopover and wintering habitats. This project provides the first implementation of archival light-level geolocator data logger technology by a Puerto Rican institution to study the migratory connectivity of Neotropical migratory birds in Puerto Rico and complements existing information derived from banding returns and stable isotope analyses to determine the geographic origins in North America of birds that occur in Puerto Rico during the non-breeding seasons. We apply this technology,
... Temperature and precipitation parameters are some of the most important issues related to climate change and the extreme events that affect our lives. There has been a growing awareness about extreme events in the last two decades, and many researchers found warming trends in surface temperatures around the world, although the magnitude of those changes has not been uniform (see, for example, Jones and Moberg 2003;Solomon et al. 2007;Kerr 2009;Abbasnia et al. 2016). Recent data have shown that the global average temperature has increased by 0.85°C over the last century (IPCC 2013). ...
... Temperature is the most important issue of climate change and extreme temperatures affect our lives the most. Many researchers found warming trends in surface temperature over the world, but the magnitude of changes is not uniform (e.g., Jones and Moberg 2003;Solomon et al. 2007;Kerr 2009;Abbasnia et al. 2016). Recently, global average temperature has shown a 0.85 C increase over the last century (IPCC, 2013). ...
Efforts to place recent climate observations in a long-term context have been driven by concerns about whether the global warming trend of the 20th century is part of natural climate variability or whether it is linked to increased anthropogenic emissions of greenhouse gases in the atmosphere. A new perspective on the climate and its changes is offered, highlighting those that occur due to natural cycles, which are generally not widespread. With the historical background on how the climate varied in the past, statistical research was conducted using time series techniques and spectral/harmonic analysis (Fourier series and spectrograms), which allowed the determination of periodic natural phenomena and their magnitudes in national variations of temperature. It was identified that the air surface temperature in Brazil expresses cycles of 4 years (oceanic-atmospheric origin related to ENSO), 33 years (Brückner cycles, lunar-solar origin) and 82 years (lower Gleissberg cycle, solar origin). Based on an alternative oscillatory model that incorporates such natural cycles, future projections of the air temperature in the country were prepared. For the year 2100, it is predicted that the air temperature in Brazil may reach the value of +1.8 ± 0.6 °C, according to the natural oscillatory model. In comparison, conventional models typically used by the IPCC indicate, by the end of the century, an increase of: +2.9 ± 1.2 °C (RCP4.5 model, with mitigation); +3.9 °C (SRES A1 model); and +5.7 ± 1.7 °C (RCP8.5 model, without mitigation). The most extreme values of conventional models reach proportions up to 4 times greater than the results obtained in the alternative model provided here. Analyzing the adherence of the models, it is concluded that the conventional models are overestimating and exaggerating a warming rate in Brazil that, in reality, has not been observed. The proposed natural oscillatory model, which has a high correlation with the data observed so far, indicates an increase in temperature in Brazil that may reach a modest value of +0.8 °C in 2040. For the same year, the SRES A1 and RCP8.5 models indicate values around +2.0 °C – which represents more than double of the projection based on natural climate cycles. Based on the projections that indicate a moderate warming, not so exaggerated, a new perspective of a less terrifying future climate is offered. In a context in which pernicious alarmist discourses predominate, spreading scenarios of apocalyptic global warming, it is hoped that new pondered views could help to appease the level of concern that today, has culminated in undesirable side effects - especially the high levels of eco-anxiety that has afflicted significant portions of society.
The thermocline-sea surface temperature (SST) feedback is the most important component of the Bjerknes feedback, which plays an important role in the development of the air-sea coupling modes of the Indian Ocean. The thermocline-SST feedback in the Indian Ocean has experienced significant decadal variations over the last 40 a. The feedback intensified in the late twentieth century and then weakened during the hiatus in global warming at the early twenty-first century. The thermocline-SST feedback is most prominent in the southeastern and southwestern Indian Ocean. Although the decadal variations of feedback are similar in these two regions, there are still differences in the underlying mechanisms. The decadal variations of feedback in the southeastern Indian Ocean are dominated by variations in the depth of the thermocline, which are modulated by equatorial zonal wind anomalies. Whereas the decadal variation of feedback in the southwestern Indian Ocean is mainly controlled by the intensity of upwelling and thermocline depth in winter and spring, respectively. The upwelling and thermocline depth are both affected by wind stress curl anomalies over the southeastern Indian Ocean, which excite anomalous Ekman pumping and influence the southwestern Indian Ocean through westward propagating Rossby waves.
There are heated debates on the existence of the global warming slowdown during the early 21st century. Although efforts have been made to clarify or reconcile the controversy over the issue, it is not explicitly addressed, restricting the understanding of global temperature change particularly under the background of increasing greenhouse-gas concentrations. Here, using extensive temperature datasets, we comprehensively reexamine the existence of the slowdown under all existing definitions during all decadal-scale periods spanning 1990-2017. Results show that the short-term linear-trend dependent definitions of slowdown make its identification severely suffer from the period selection bias, which largely explains the controversy over its existence. Also, the controversy is further aggravated by the significant impacts of the differences between various datasets on the recent temperature trend and the different baselines for measuring slowdown prescribed by various definitions. However, when the focus is shifted from specific periods to the probability of slowdown events, we find the probability is significantly higher in the 2000s than in the 1990s, regardless of which definition and dataset are adopted. This supports a slowdown during the early 21st century relative to the warming surge in the late 20th century, despite higher greenhouse-gas concentrations. Furthermore, we demonstrate that this decadal-scale slowdown is not incompatible with the centennial-scale anthropogenic warming trend, which has been accelerating since 1850 and never pauses or slows. This work partly reconciles the controversy over the existence of the warming slowdown and the discrepancy between the slowdown and anthropogenic warming.
The attribution analysis of China surface temperature(TC) in the recent 100 years is done from the angle of the astronomical factor(sunspot number, SSN) and the earth movement factor(polar shift x direction and y direction ) by using Granger causality test. The results are as follows: (1) SSN is not the Granger cause of TC in all of 1 to 11 years lags; (2) when the lag is 6 years, confidence is the highest, at this time polar shift x direction is the Granger cause of TC (87% confidence); (3) when the lag is 12 years, TC is the Granger cause of the polar shift y direction, the confidence is 86%. The research results of the paper suggest that the change of polar shift x direction possibly results in the change of TC, and the change of TC possibly influences the change of the polar shift y direction.
The mechanism of the abrupt temperature change‐climate warming hiatus is not clear, and understanding the response relationships between it and the influencing factors is significant to the study the mechanism. Based on the annual average temperature (Tave), annual average minimum temperature (Tmin), and annual average maximum temperature (Tmax) of 622 meteorological stations in China from 1951 to 2018, the response relationships between the three temperatures and the influencing factors were analyzed. The results showed that In the periods before, during, and after an abrupt temperature change, For the abrupt changes in the three temperatures, the regions significantly influenced by the solar radiation (SR), AMO, multivariate El Niño southern oscillation (ENSO) index (MEI), and Pacific Decadal Oscillation (PDO) accounted for more than 80% of China, and for the abrupt changes in Tmin, the regions with significant influences covered the whole of China. The regions significantly influenced by the AO accounted for more than 60% of China, and the regions significantly influenced by the remaining factors accounted for more than 30% of China. The AO mainly influenced the abrupt temperature change in the northern regions, the AGG and CO2 mainly influenced all the regions except for Northeast China, and the influencing scopes of the atmospheric pressure (AP) were relatively small and not concentrated. In summary, when some conditions continued for a period and a tendency rate or value was reached, abrupt temperature change occurred, and the conditions were as follows: the AGG continued to increase, the PDO was in a positive phase, the AMO and SR continued to rise, the MEI changed abruptly, and theAP in each zone continued to decline/increase and experienced the subsequent trend change. In the periods before, during, and after the climate warming hiatus, few influencing factors had a significant correlation with the temperatures. The MEI and PDO influenced more than 80% of the regions that experienced the climate warming hiatus, and other factors influenced less than 60% of these regions. In the 1990s, especially after 1998, the increase in the AGG slowed, the PDO declined or was in a negative phase, the MEI and SR decreased, and the AP in each zone continued to decline/increase and experienced the subsequent trend change; when those conditions continued for a period and a tendency rate or value was reached, the climate warming hiatus occurred. The abrupt temperature change‐climate warming hiatus was the result of the joint action of multiple influencing factors. This article is protected by copyright. All rights reserved.
Global mean surface air temperature (SAT) has remained relative stagnant since the late 1990s, a phenomenon known as global warming hiatus. Despite widespread concern and discussion, there is still an open question about whether this hiatus exists, partly due to the biases in observations. The stable isotopic composition of precipitation in mid- and high-latitude continents closely tracks change of the air temperature, providing an alternative to evaluate global warming hiatus. Here we use the long-term precipitation δ¹⁸O records available to investigate changes in SAT over the period 1970–2016. The results reveal slight decline in δ¹⁸O anomaly from 1998 to 2012, with a slope of −0.000 4‰ decade⁻¹ which is significantly different from that of pre-1998 interval This downward δ¹⁸O anomaly trend suggests a slight cooling for about −0.001 oC decade⁻¹, corroborating the recent hiatus in global warming. Our work provides new evidence for recent global warming hiatus and highlights the potential of utilizing precipitation isotope for tracking climate changes.
A severe low‐temperature snowstorm and ice freezing event occurred in China in early 2018. This event was similar to that occurred in early 2008 but with a weaker intensity and salient difference in location and extent. The reason for this discrepancy was investigated in this study using station data and atmospheric reanalysis data. The results reveal that two different circulation patterns (i.e., zonal dipole pattern and meridional dipole pattern) over the mid‐high latitudes of Eurasia played an important role. The zonal dipole pattern, which is closely related to the 2018 event, is characterized by positive anomalies over the Ural Mountains and negative anomalies over Lake Baikal in the 500 hPa geopotential height field. This pattern can cause intense low temperatures in northern China through its influence on the anomalous cyclone over Northeast Asia. The meridional dipole pattern, which is highly associated with the 2008 event, is characterized by positive anomalies over Siberia and negative anomalies over Asia in the 500 hPa geopotential height field. This pattern corresponds to a strong East Asian winter monsoon (EAWM) and can drive cold air to move further southward, causing nearly nationwide chilly weather, particularly in northwestern China and south of the Yangtze River valley. The two patterns, combined with the strengthened western Pacific subtropical high (WPSH), have a synergistic role in the occurrence of snowfall. However, these patterns have weak correlations with the number of icy days but provide favorable conditions for ice freezing events. This article is protected by copyright. All rights reserved.
Experimentally there is an ongoing debate regarding the structure of pure liquid water at ambient conditions. One set of experimental data suggests that over 80% of hydrogen bonds are existent in liquid water giving it a crystalline tetrahedron structure similar to solid water. Other experimental data says that only 20% of hydrogen bonds exist in water making the system seem more like a disorderly liquid. In this project Ab Initio Molecular Dynamics (AIMD) and statistical mechanics were used to study the structural and dynamical properties of pure water at ambient conditions. Two different density functionals PerdewBurke-Ernzenhof (PBE), Becke-Lee-Yang-Parr with an empirical correction (BLYP-D3), and Q-TIP4P (a four point charge force field) were used to describe the system. The system conditions were constructed in a periodic boundary cube containing 32 water molecules. The VASP code was used to run simulations. Some disadvantages when running computer simulations for pure water are that most functionals over structure water at ambient conditions. Here we present the impact of these approximations on structural properties such as the radial distribution functions, tetrahedrality parameters, hydrogen bond (HB) angles, and percentage of broken HB’s in liquid water. The two functionals and the force field are compared to each other and to experimental results to help determine a defined structure for liquid water. After running the simulations it is seen that the BLYP-D3 functional and the Q-TIP4P force field yield a less over- structured liquid than PBE with a smaller molecular dipole moment and a higher number of broken HB’s. HB’s give us an idea of how structured the liquid is. If it has a high number of HB’s it appears to be more like a solid. PBE gave a number of 72% HB, BLYP-D3 48% and Q-TIP4P 43% which tells us how disordered the liquid is. In the future, we hope to implement a couple clustered corrections to the BLYP-D3 functional to correct the proton ion interaction and nuclear quantum effects for water which we expect will help fix over-structuring. We are also interested in studying ion solvation particularly H3O+ and OH- in water to study proton transfer properties.
The Mediterranean Sea, as a “centre” of the ancient world, has been early recognized as a laboratory basin for a variety of atmospheric, ocean and climate studies. Its uniqueness is manifested in its geographical position, a mid-latitude region connecting three continents, orography that affects cyclogenesis, precipitation and winds, ocean bathymetry that is shaped by narrow and shallow straits, passages and sills, and other. Its both atmospheric and oceanic climate is distinctive and, while differing substantially from neighbouring continents and oceans, it strongly interferes and shapes their properties. One of such adjacent basins is the Black Sea, which is, albeit minor in quantity, providing a noteworthy impact to the Mediterranean and vice versa. This topical volume of Pure and Applied Geophysics is presenting recent investigations of atmospheric and ocean properties, processes and climate of both basins, being inspired by presentations given in the Joint Congress of the 6th International Conference on Meteorology and Climatology of the Mediterranean & Challenges in Meteorology 5, held in Zagreb, Croatia, on 20-22 February 2017. The volume comprises 22 papers that are classified in three research categories: (1) storms, extremes and mesoscale processes, (2) atmospheric climate, variability and climate change, and (3) ocean climate and variability. The papers investigate processes occurring over a variety of spatial and temporal scales, from hemispheric processes that drive the observed changes in the Mediterranean and Black Sea, through phenomena that are influencing the whole basin or its sub-basins, to local and mesoscale extreme events that are affecting large cities and local populations in the region. The volume is of interest to atmospheric and oceanic researchers involved in a variety of processes that are occurring over the Mediterranean and Black Sea region. This particularly refers to young researchers and PhD students that are yet to enter to research of this unique and exciting region full of challenges that need an interdisciplinary, innovative and state-of-the-art approaches in solving actual research problems.
In this study, the possible effects of subduction rate on global warming hiatus were investigated using Simple Ocean Data Assimilation (SODA) data. This study first analyzed the characteristics of the temporal and spatial distribution of global subduction rate, which revealed that the North Atlantic meridional overturning circulation region and the Antarctic Circumpolar Current region are the two main sea areas with great subduction variations. On this basis, four key areas were selected to explore the relationship between the local subduction rate and the global mean sea surface temperature. In addition, the reason for the variations in subduction rate was preliminarily explored. The results show good correspondence of the subduction of the key areas in the North Atlantic meridional overturning the circulation region and the Antarctic Circumpolar Current region to the global warming hiatus, with the former leading by about 10 years. The subduction process may be a physical mechanism by which the North Atlantic overturning circulation and the Antarctic Circumpolar Current act on the stagnation of global warming. Advection effect plays an important role in the variations in subduction in the key regions. In the Antarctic Circumpolar Current region, the magnitude of sea surface wind stress is closely related to the local changes in subduction.
Climate change detection and attribution have proven unexpectedly challenging during the 21st century. Earth’s global surface temperature increased less rapidly from 2000 to 2015 than during the last half of the 20th century, even though greenhouse gas concentrations continued to increase. A probable explanation is the mitigation of anthropogenic warming by La Niña cooling and declining solar irradiance. Physical climate models overestimated recent global warming because they did not generate the observed phase of La Niña cooling and may also have underestimated cooling by declining solar irradiance. Ongoing scientific investigations continue to seek alternative explanations to account for the divergence of simulated and observed climate change in the early 21st century, which IPCC termed a “global warming hiatus.” Amplified by media commentary, the suggestions by these studies that “missing” mechanisms may be influencing climate exacerbates confusion among policy makers, the public and other stakeholders about the causes and reality of modern climate change.
Understanding and communicating the causes of climate change in the next 20 years may be equally challenging. Predictions of the modulation of projected anthropogenic warming by natural processes have limited skill. The rapid warming at the end of 2015, for example, is not a resumption of anthropogenic warming but rather an amplification of ongoing warming by El Niño. Furthermore, emerging feedbacks and tipping points precipitated by, for example, melting summer Arctic sea ice may alter Earth’s global temperature in ways that even the most sophisticated physical climate models do not yet replicate.
This article is categorized under:
• Paleoclimates and Current Trends > Climate Forcing
This project was established to (1) support and develop a recently established academic program in ornithology and avian conservation (the only such effort in Puerto Rico); (2) employ mist netting, color banding census, stable isotopic analysis, light-level geolocators and mitochondrial DNA (mtDNA) (for Northern Waterthrushes (Parkesia noveboracensis) techniques to establish links between breeding and wintering populations of migratory songbirds that nest in North America and winter, or stop over in Puerto Rico; and, (3) establish a long-term monitoring program for migratory and year-round resident species of terrestrial birds that utilize secondary coastal dry forest and mangroves in and around the area of the Jobos Bay National Estuarine Research Reserve (JBNERR). The project includes undergraduate and graduate student research focusing on long-distance migratory and interhabitat movement, habitat quality, and social structure of migrants and nesting residents, and promote and enhance the academic and professional development of ornithology and citizen science in Puerto Rico. We collected feather samples for stable isotope analysis and mtDNA analysis. Analysis of our first replicate of feather samples and comparison to the new feather isotope atlas for North America have already provided noteworthy results. For ground foragers (Northern Waterthrushes (Parkesia noveboracensis), Ovenbirds (Seiurus aurocapillus)), we found statistical differences overall between the isotopic signatures of wing (P1) and tail (R1) feathers, and discrepancies did occur between specific Isotopic Region assignments of individuals. Similar results were found for canopy foragers, Yellow Warblers ((Setophaga petechia), Prairie Warblers (Setophaga discolor) and Bananaquits (Coereba flaveola)), and there was statistical significance overall between wing and tail feather isotopic signatures of these species. Results also indicate that some individuals continued molting during migration and even upon arrival in Puerto Rico. Some individuals of the canopy foraging species displayed feather isotopic signatures indicative of the marine/mangrove environment, and about 13% of Yellow Warblers sampled appear to be migrants rather than local residents. Resumen. Este proyecto fue establecido para (1) apoyar y desarrollar un programa académico recientemente establecido en ornitología y conservación de 40 Ambientis 2017: 39-58. © Copyright 2017, The Authors and Ambientis aves (el único esfuerzo en Puerto Rico); (2) emplear redes de niebla, análisis de bandas de color, análisis isotópico estable, geolocadores de luz y ADN mitocondrial (ADNmt) para establecer vínculos entre las poblaciones reproductoras e invernales de aves canoras migratorias que anidan en América del Norte (3) establecer un programa de monitoreo a largo plazo para las especies migratorias y residentes a lo largo de todo el año de aves terrestres que utilizan bosques secos costeros secundarios y manglares en y alrededor de la zona de la la Reserva Nacional de Investigación Estuarina de la Bahía de Jobos (JBNERR) El proyecto incluye la investigación de estudiantes de bachillerato y posgrado en el movimiento migratorio e interhabitat de larga distancia, la calidad del hábitat y la estructura social de los migrantes y residentes de anidación, y promover y mejorar el desarrollo académico y profesional de ornitología y ciencia de ciudadano en Puerto Rico. Las muestras de plumas se han recolectado para análisis de isótopos estables y ADNmt El análisis de nuestra primera réplica de muestras de plumas y la comparación con el nuevo atlas de isótopos de plumas para América del Norte ya han proporcionado resultados notables. Se encontraron diferencias estadísticamente significativas entre las firmas isotópicas de las plumas de ala (P1) y de cola (R1), y se observaron discrepancias entre las asignaciones específicas de la Región Isotópica de los individuos de la Pizpita de Mangle (Parkesia noveboracensis), Pizpita Dorada (Seiurus aurocapillus) Se encontraron resultados similares para las que aprovisionan en el dosel como el Canario de Mangle (Setophaga petechia), la Reinita Galana (Setophaga discolor) y la Reinita Común (Coereba flaveola), y hubo significancia estadística entre las concentraciones isotópicas de estas especies. Los resultados también indican que algunos individuos continuaron muda durante la migración e incluso a su llegada a Puerto Rico. Algunos individuos de las especies aprovisionan en el dosel mostraron signos isotópicos de plumas indicativos del medio ambiente marino / manglar, y alrededor del 13% de los Canarios de Mangle muestreados parecen ser migrantes en lugar de residentes locales.
The effective conservation of long-distance migratory birds requires the identification and protection of the birds, nesting habitat as well as their stopover and wintering habitats. This project provides the first implementation of archival light-level geolocator data logger technology by a Puerto Rican institution to study the migratory connectivity of Neotropical migratory birds in Puerto Rico and compliments existing information derived from banding returns and stable isotope analyses to determine the geographic origins in North America of birds that occur in Puerto Rico during the non-breeding seasons. We applied this technology to help establish the specific intercontinental migratory connectivity of the 15-20 g Northern Waterthrush (Parkesia noveboracensis), a species breeds in North America
This project was established to (1) support and develop a recently established academic program in ornithology and avian conservation (the only such effort in Puerto Rico); (2) employ mist netting, color banding census, stable isotopic and light-level geolocator and mitochondrial DNA (mtDNA) (for Northern Waterthrushes (Parkesia noveboracensis) techniques to establish links between breeding and wintering populations of migratory songbirds that nest in North America and winter, or stop over in Puerto Rico; and, (3) establish a long-term monitoring program for migratory and year-round resident species of terrestrial birds that utilize secondary coastal dry forest and mangroves in and around the area of the Jobos Bay National Estuarine Research Reserve (JBNERR). The project includes undergraduate and graduate student research focusing on long-distance migratory and interhabitat movement, habitat quality, and social structure of migrants and nesting residents, and promote and enhance the academic and professional development of ornithology and citizen science in Puerto Rico. Feather samples have been collected for stable isotope analysis and mtDNA analysis, and the purchase of geolocators and software is under way. Analysis of our first replicate of feather samples and comparison to the new feather isotope atlas for North America have already provided noteworthy results. For ground foragers (Northern Waterthrushes (Parkesia noveboracensis), Ovenbirds (Seiurus aurocapillus)), we found statistical differences overall between the isotopic signatures of wing (P1) and tail (R1) feathers, and discrepancies did occur between specific Isotopic Region assignments of individuals. Similar results were found for canopy foragers, Yellow Warblers ((Setophaga petechia), Prairie Warblers (Setophaga discolor) and Bananaquits (Coereba flaveola)), and there was statistical significance overall between wing and tail feather isotopic signatures of these species. Results also indicate that some individuals continued molting during migration and even upon arrival in Puerto Rico. Some 2 individuals of the canopy foraging species displayed feather isotopic signatures indicative of the marine/mangrove environment, and about 13% of Yellow Warblers sampled appear to be migrants rather than local residents. Data collected on habitat use and bird abundance and body condition are currently being summarized and analyzed.
This project was established to (1) support and develop a recently established academic program in ornithology and avian conservation (the only such effort in Puerto Rico); (2) employ mist netting, color banding census, stable isotopic and light-level geolocator and mitochondrial DNA (mtDNA) (for Northern Waterthrushes (Parkesia noveboracensis) techniques to establish links between breeding and wintering populations of migratory songbirds that nest in North America and winter, or stop over in Puerto Rico; and, (3) establish a long-term monitoring program for migratory and year-round resident species of terrestrial birds that utilize secondary coastal dry forest and mangroves in and around the area of the Jobos Bay National Estuarine Research Reserve (JBNERR). The funds requested provided continuing support for undergraduate and graduate student research focusing on long-distance migratory and interhabitat movement, habitat quality, and social structure of migrants and nesting residents, and promote and enhance the academic and professional development of ornithology and citizen science in Puerto Rico. Samples have been collected for stable isotope analysis and mtDNA analysis, and the purchase of geolocators and software is under way. Analysis of our first replicate of feather samples and comparison to the new feather isotope atlas for North America have already provided noteworthy results. For ground foragers (Northern Waterthrushes (Parkesia noveboracensis), Ovenbirds (Seiurus aurocapillus)), we found statistical differences overall between the isotopic signatures of wing (P1) and tail (R1) feathers, and discrepancies did occur between specific Isotopic Region assignments of individuals. Similar results were found for canopy foragers, Yellow Warblers ((Setophaga petechia), Prairie Warblers (Setophaga discolor) and Bananaquits (Coereba flaveola)), and there was statistical significance overall between wing and tail feather isotopic signatures of these species. Results also indicate that some individuals continued molting during migration and even upon arrival in Puerto Rico. Some individuals of the canopy foraging species displayed feather isotopic signatures indicative of the marine/mangrove environment, and about 13% of Yellow Warblers sampled appear to be migrants rather than local residents. 2
This project was established to (1) support and develop a recently established academic program in ornithology and avian conservation (the only such effort in Puerto Rico); (2) employ mist netting, color banding census, stable isotopic and light-level geolocator and mitochondrial DNA (mtDNA) (for Northern Waterthrushes (Parkesia noveboracensis) techniques to establish links between breeding and wintering populations of migratory songbirds that nest in North America and winter, or stop over in Puerto Rico; and, (3) establish a long-term monitoring program for migratory and year-round resident species of terrestrial birds that utilize secondary coastal dry forest and mangroves in and around the area of the Jobos Bay National Estuarine Research Reserve (JBNERR). The funds requested provided continuing support for undergraduate and graduate student research focusing on long-distance migratory and interhabitat movement, habitat quality, and social structure of migrants and nesting residents, and promote and enhance the academic and professional development of ornithology and citizen science in Puerto Rico. Samples have been collected for stable isotope analysis and mtDNA analysis, and the purchase of geolocators and software is under way. Analysis of our first replicate of feather samples and comparison to the new feather isotope atlas for North America have already provided noteworthy results. For ground foragers (Northern Waterthrushes (Parkesia noveboracensis), Ovenbirds (Seiurus aurocapillus)), we found statistical differences overall between the isotopic signatures of wing (P1) and tail (R1) feathers, and discrepancies did occur between specific Isotopic Region assignments of individuals. Similar results were found for canopy foragers, Yellow Warblers ((Setophaga petechia), Prairie Warblers (Setophaga discolor) and Bananaquits (Coereba flaveola)), and there was statistical significance overall between wing and tail feather isotopic signatures of these species. Results also indicate that some individuals continued molting during migration and even upon arrival in Puerto Rico. Some individuals of the canopy foraging species displayed feather isotopic signatures indicative of the marine/mangrove environment, and about 13% of Yellow Warblers sampled appear to be migrants rather than local residents. 2
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