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Urbanization: Its Detection and Effect in the United States Climate Record

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Several equations were developed that related the effect of urban growth, measured by increasing population, to the mean seasonal and annual temperature: the diurnal maximum, minimum, average, and range. These equations were derived from a network of 1219 stations across the United States, which were analyzed for the years 1901-84. The results indicate that urban effects on temperature are detectable even for small towns with populations under 10 000. Stations with populations near 10 000 are shown to average 0.1°C warmer for the mean annual temperature than nearby stations located in rural areas with populations less than 2000. Urbanization decreases the daily maxima in all seasons except winter and the temperature range in all seasons. It increases the diurnal minima and the daily means in all seasons.The equations indicate that, for the annual mean temperature, urbanization during the twentieth century accounts for a warm bias of about 0.06°C in the U.S. Historical Climatology Network (HCN). Due to the large number of stations located in sparsely populated arms [(over 85% (70%) of all stations had a 1980 population of less than 25 000 (10 000)], the impact of urbanization is not large in relation to decadal changes of temperature in the United States. The average heat island impact during the period 1901-84 for the HCN is largest for the daily minima (0.13°C) and the temperature range (0.14°C), while the impact on the daily maxima (0.01°C) is an order of magnitude smaller.
... The reason is that cloudiness and rainfall are more common during the monsoon. The DTR is reported to be affected by other additional factors including land-use/ land-cover changes (Gallo et al. 1996), irrigation (Karl et al. 1988), desertification, and other climatic effects (Karl et al. 1993). Urbanization, also, has been extensively investigated in many papers (Karl et al. 1988;Landsberg 1981;Wang et al. 2012) and it has been found that the DTR would shift in an asymmetrical manner as the population of an urban centre increases (Karl et al. 1991). ...
... The DTR is reported to be affected by other additional factors including land-use/ land-cover changes (Gallo et al. 1996), irrigation (Karl et al. 1988), desertification, and other climatic effects (Karl et al. 1993). Urbanization, also, has been extensively investigated in many papers (Karl et al. 1988;Landsberg 1981;Wang et al. 2012) and it has been found that the DTR would shift in an asymmetrical manner as the population of an urban centre increases (Karl et al. 1991). Despite these confounding variables, many studies have been conducted on DTR where most of the studies have utilized station observations and DTR trends are analysed on global level (Karl et al. 2004(Karl et al. , 1991Easterling et al. 1997;Leathers et al. 1998) has studied the decreasing DTR in the United States and Canada. ...
... (accessed on 2 September 2020), including data from the Shapingba meteorological station in the central urban areas and the Hechuan meteorological station in rural areas of Chongqing from 1959 to 2018 ( Figure 1). The selection principle of meteorological representative stations in central urban and rural areas is mainly determined according to the accumulation time and continuity of meteorological data and location and relocation of meteorological stations [30]. These stations were selected from National Principal Meteorological Stations, and their details are illustrated in Table 1. ...
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Urban development always has a strong impact on the urban thermal environment, but it is unclear to what extent urbanization factors influence urban heat island intensity (UHII) in mountainous cities, and fewer studies have been conducted on the trends of long-term UHII in mountainous cities. Chongqing, as the only municipality directly under the central government in Southwest China and a typical mountainous city, is chosen as the case study. This study analyzed the interannual and seasonal variations of UHII based on the data from meteorological stations in Chongqing from 1959 to 2018 using the least-squares method and the Mann–Kendall test, and explored the relationship between urbanization factors (urban resident population, gross domestic product (GDP), fixed investments, and gross industrial output value) and UHII. The results show that the increasing rates of temperature in urban areas of Chongqing are significantly higher than those in rural areas affected by urbanization. Using the Mann–Kendall test, it is found that almost all abrupt temperature changes in Chongqing occurred after the rapid urbanization of Chongqing in the 21st century. The annual mean UHII increased from 0.1 °C to 1.5 °C during the study period, with summer making the largest contribution. It is also found that the UHII in Chongqing has increased year by year, especially after the 1980s. The increasing rates of UHII are larger at night and smaller during the day. The increasing trends of nighttime UHII are statistically significant, while those of daytime UHII are not. In addition, UHII and urbanization factors are found to be correlated using the grey relational analysis (GRA). Eventually, a comprehensive UHII index and a comprehensive urbanization index are constructed using principal component analysis (PCA). A tertiary regression model of UHII and urbanization index is established, which reflects that the UHII in Chongqing will continue to grow rapidly with the development of the city.
... The LST can provide information related to fluctuation in surface temperature due to various determinants such as concretization, massive alterations in land-use cover (vegetation to built-up), increment in population density, vehicular movement, etc. disturbs the surrounding natural environment. In the USA, it was found that due to urbanization, there is an increase in temperature by 1˚C per 100,000 populates [21]. Spatial variation in LST was observed in Delhi due to differences in population density [20], which indicates that high population density leads to higher population movement at the local level, leading to an increase in the LST. ...
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This work quantifies the impact of pre-, during- and post-lockdown periods of 2020 and 2019 imposed due to COVID-19, with regards to a set of satellite-based environmental parameters (greenness using Normalized Difference Vegetation and water indices, land surface temperature, night-time light, and energy consumption) in five alpha cities (Kuala Lumpur, Mexico, greater Mumbai, Sao Paulo, Toronto). We have inferenced our results with an extensive questionnaire-based survey of expert opinions about the environment-related UN Sustainable Development Goals (SDGs). Results showed considerable variation due to the lockdown on environment-related SDGs. The growth in the urban environmental variables during lockdown phase 2020 relative to a similar period in 2019 varied from 13.92% for Toronto to 13.76% for greater Mumbai to 21.55% for Kuala Lumpur; it dropped to −10.56% for Mexico and −1.23% for Sao Paulo city. The total lockdown was more effective in revitalizing the urban environment than partial lockdown. Our results also indicated that Greater Mumbai and Toronto, which were under a total lockdown, had observed positive influence on cumulative urban environment. While in other cities (Mexico City, Sao Paulo) where partial lockdown was implemented, cumulative lockdown effects were found to be in deficit for a similar period in 2019, mainly due to partial restrictions on transportation and shopping activities. The only exception was Kuala Lumpur which observed surplus growth while having partial lockdown because the restrictions were only partial during the festival of Ramadan. Cumulatively, COVID-19 lockdown has contributed significantly towards actions to reduce degradation of natural habitat (fulfilling SDG-15, target 15.5), increment in available water content in Sao Paulo urban area(SDG-6, target 6.6), reduction in NTL resulting in reducied per capita energy consumption (SDG–13, target 13.3).
... El inicio fenológico de la primavera se correlaciona muy bien con las temperaturas del aire, la vernalización y las temperaturas cálidas posteriores (Murphy et al., 1999). En los asentamientos urbanos se ha documentado un incremento de la temperatura media anual mayor que el de las áreas circundantes (Karl et al., 1988). Asimismo, se ha encontrado que la isla de calor urbano (ICU) puede ser un factor preponderante en el adelantamiento de las fenofases primaverales (Jeong, 2011). ...
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La distribución de la radiación solar es considerada como el elemento microclimático más importante en una comunidad vegetal. El coeficiente de extinción de luz del dosel (k) es un factor importante al aplicar la ley de Lambert-Beer en cultivos, ya que su valor está determinado por la estructura del dosel, la especie y el patrón de plantación (Zarea et al., 2005). Arundo donax L. es una especie C3, que se propaga vegetativamente a partir de fragmentos de tallos y rizomas. Esto puede limitar el cultivo a gran escala, ya que lleva mucho tiempo e implica costos y esfuerzos considerables. El cultivo de tejidos permite obtener plantas libres de enfermedades, a la vez facilita propagar masivamente material vegetal en cualquier época del año, conservando su potencial genético y calidad sanitaria, cualidades apreciadas para realizar un cultivo (Cavallaro et al., 2011). (Falasca, et al., 2011) delimitaron las áreas aptas para el cultivo en Argentina y concluyeron que la región Centro-Sur de la Provincia de Buenos Aires es apta, ya que presenta adecuada disponibilidad de energía radiante. En condiciones óptimas de crecimiento, la productividad de la biomasa puede describirse por la cantidad de radiación solar interceptada por las hojas principalmente y la eficiencia con la que dicha radiación interceptada se convierte en materia seca vegetal. (Cosentino et al., 2016) encontraron valores de eficiencia en el uso de la radiación (EUR), en experimentos realizados en Italia, que van desde 1,26 g/MJ cuando crece sin riego ni fertilización, llegando a 1,94 g/MJ en condiciones potenciales. En Italia, en condiciones ambientales favorables, se ha informado de un notable rendimiento durante el primer año de cultivo, superior a 20 t/ha (Cosentino et al., 2016). Sin embargo, no está claro que puedan obtenerse esos resultados en condiciones de cultivo en nuestra región pampeana. El objetivo del trabajo fue determinar la producción de biomasa en función de la intercepción y eficiencia de utilización de la radiación, de un cultivo de Arundo donax L., en condiciones potenciales (con riego y fertilización) y reales (sin riego, ni fertilización), en Azul, centro geográfico de la provincia de Buenos Aires, partiendo de plantines obtenidos por técnicas de micropropagación.
... El inicio fenológico de la primavera se correlaciona muy bien con las temperaturas del aire, la vernalización y las temperaturas cálidas posteriores (Murphy et al., 1999). En los asentamientos urbanos se ha documentado un incremento de la temperatura media anual mayor que el de las áreas circundantes (Karl et al., 1988). Asimismo, se ha encontrado que la isla de calor urbano (ICU) puede ser un factor preponderante en el adelantamiento de las fenofases primaverales (Jeong, 2011). ...
Conference Paper
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La utilización del concepto de tasa de desarrollo (inversa del tiempo de duración) permite conocer la respuesta fenológica de los cultivos (De Wit, 1970). La fenología de cereales y leguminosas de invierno es regulada principalmente por la repuesta genética a la temperatura y fotoperíodo de tal forma que se puede analizar la duración de un subperíodo -o el ciclo completo- por medio de funciones lineales entre los mismos (Confalone et al., 2011). La cebada tiene una respuesta fotoperiódica de tipo cuantitativa de día largo. Es decir, que a medida que se incrementa el fotoperíodo (de junio a diciembre en el hemisferio sur), el ciclo ontogénico se acorta gradualmente hasta un determinado punto llamado fotoperíodo umbral, en el cual se llega al fotoperíodo óptimo, donde la respuesta a este factor se satura y su duración solo es modificada por la temperatura (Miralles et al., 2014). La sensibilidad frente al fotoperíodo y el fotoperíodo umbral son características genéticas y por lo tanto, variables entre cultivares de cebada, incluso la sensibilidad varía también en un mismo cultivar para diversas etapas del desarrollo. Por esto, la predicción de la fenología de distintos materiales es una valiosa estrategia para escapar a diferentes eventos de estrés, así como proveer las condiciones propicias para aumentar la duración de ciertas etapas vinculadas estrechamente a la generación de rendimiento (Ramirez-Cáceres, 2013). El objetivo de este trabajo fue cuantificar el subperíodo emergencia-encañazón (E-En) de un cultivar de cebada por medio de un modelo lineal aditivo considerando la interacción entre temperatura y fotoperíodo
... El inicio fenológico de la primavera se correlaciona muy bien con las temperaturas del aire, la vernalización y las temperaturas cálidas posteriores (Murphy et al., 1999). En los asentamientos urbanos se ha documentado un incremento de la temperatura media anual mayor que el de las áreas circundantes (Karl et al., 1988). Asimismo, se ha encontrado que la isla de calor urbano (ICU) puede ser un factor preponderante en el adelantamiento de las fenofases primaverales (Jeong, 2011). ...
Presentation
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El impacto de los combustibles fósiles sobre la generación de gases de efecto invernadero (GEIs) ha intensificado el estudio de nuevas fuentes de energía renovables, entre ellas los cultivos energéticos, ya que desacelerar el calentamiento global es el principal desafío ambiental para la humanidad (IPCC, 2014). Arundo donax L. (caña de Castilla) es una especie C3 pero de alta eficiencia fotosintética que se reproduce por rizomas. Una vez implantado, el cultivo puede dar producciones durante 15 a 20 años con una elevada capacidad de reproducción vegetativa. Si bien en otros países la rápida velocidad de producción de biomasa la ubican como candidata para el desarrollo de biocombustibles (Barney y Di Tomaso, 2008), en Argentina hasta la actualidad es considerada una maleza. Aun así, Falasca et al. (2011) analizaron el potencial de la caña de Castilla en nuestro país y determinaron la factibilidad de cultivo para una amplia zona. En un ensayo preliminar en Azul (Facultad de Agronomía-UNCPBA), la producción de biomasa en el primer año de cultivo fue entre 5196 y 11317 kg/ha para densidades de 1 y 2 plantas/m2, respectivamente (Barrado et al., 2019), lo que demuestra la posibilidad de convertirse en un cultivo energético en nuestra región. El objetivo de este trabajo fue ampliar la información existente y evaluar cómo el manejo del cultivo: condiciones potenciales (con riego y fertilización) y reales (sin riego, ni fertilización) en Azul, centro geográfico de la provincia de Buenos Aires , afectan la determinación del crecimiento y la producción de biomasa.
... El inicio fenológico de la primavera se correlaciona muy bien con las temperaturas del aire, la vernalización y las temperaturas cálidas posteriores (Murphy et al., 1999). En los asentamientos urbanos se ha documentado un incremento de la temperatura media anual mayor que el de las áreas circundantes (Karl et al., 1988). Asimismo, se ha encontrado que la isla de calor urbano (ICU) puede ser un factor preponderante en el adelantamiento de las fenofases primaverales (Jeong, 2011). ...
Conference Paper
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La temperatura es la principal causa de variación anual en el desarrollo de los cultivos y en algunas especies, la duración del fotoperíodo influye también en el mismo. De esa forma, la relación entre temperatura y desarrollo sustentó la elaboración de los modelos para el cálculo de las sumas térmicas usadas para predecir el momento de ocurrencia de distintas fases fenológicas o etapas del desarrollo. Las distintas versiones de los métodos de sumas térmicas difieren en el grado de precisión de sus previsiones, en función de las interacciones entre la variación del tiempo meteorológico y la fisiología del cultivo (Confalone y Navarro, 1999). El ciclo ontogénico de los cereales está dividido en etapas de desarrollo o fases fenológicas: emergencia, macollaje, encañazón, espigazón, antesis, llenado de grano, madurez fisiológica. La tasa de desarrollo determina la duración del ciclo y tiene una respuesta universal a la temperatura (Sadras et al., 2000), puesto que en todas las etapas ontogénicas a medida que la temperatura aumenta por encima de un valor base (0-4 °C) hasta un valor óptimo (25-26 °C) según el cultivar y etapa fenológica, la tasa de desarrollo se incrementa reduciendo la duración de las etapas (Miralles et al., 2014). El objetivo de este trabajo fue evaluar la performance de algunos modelos de sumas térmicas para predecir la fase fenológica de encañazón en cultivos de trigo, cebada y avena.
... The most direct reason for the increase in temperature is the increase in greenhouse gases, particularly carbon dioxide emissions. Some scholars believe that urbanization promotes carbon emissions (Huo et al., 2020), but while human socioeconomic activities lead to climate change, climate change also affects human socioeconomic activities, and there is considerable interaction between socioeconomic and climate systems (Karl et al., 1988). The heat island effect brought about by the process of urbanization (Shepherd and Burian, 2003) and the uneven distribution of precipitation will have a severe impact on the local climate (Matsumoto, 2019). ...
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Climate change, which is mainly caused by carbon emissions, has attracted attention worldwide. With the continuous increase in temperature, the urban heat island effect, extreme weather, and water shortages have seriously affected the urbanization process. Through an empirical analysis of panel data from 28 provinces in China from 2006 to 2018, this study examines the impact of climate change-induced temperature changes on the urbanization of China’s population. The results show that the urbanization level has a significant double-threshold effect on the impact of temperature on urbanization. When the urbanization level crosses the corresponding threshold value, the negative impact of temperature on urbanization is relatively weak. Understanding the impact of climate change on urbanization has become increasingly important as climate warming increases. On the one hand, the climate issue has always been a topic of common concern around the world. On the other hand, studying how climate change affects population urbanization is conducive to identifying the human factors that affect climate change and proposing corresponding solutions. Simultaneously, it also provides a reference for optimizing the distribution of urban and rural populations, and can comprehensively consider the relationship between climate change and urbanization in the formulation and implementation of policies. On this basis, the Chinese government should strengthen financial support for climate change, play a leading role in policies, improve the urban layout and structure, and increase the resilience of cities to climate change.
... Long-term in-situ observations can have inhomogeneities due to various reasons like changes in the instrumentation (Böhm et al., 2010;Changnon and Kunkel, 2006;Thorne et al., 2018), observations time or station location (Karl et al., 1986;Trewin, 2010). The rapid-growth of the urbanization in the vicinity of the meteorological stations is also documented to have an impact upon the temperatures (Gallo et al., 1999;Karl et al., 1988;Kim and Kim, 2011;Oke, 1973;Wang et al., 2015). These are known issues in the GHCNdaily data especially for the weather stations outside the United States (Menne et al., 2009) which could interfere in estimating the hemispheric or global trend in the absence of urbanization bias removal. ...
Article
Changes in frequency of record-breaking land surface temperature over Earth's since 1980 are assessed here using six different gridded datasets comprising monthly mean air temperature and weather station data retrieved from Global Historical Climatology Network and NOAA Global Summary of the Day. The 2010–2020 decade was the warmest in the history of modern measurements for more than one third of the Earth surface, i.e., Europe, United States, southern Africa, northern Siberia and most of Australia, according to four different datasets. Since 1980, new high/maximum temperature records have been observed in most parts of Europe, eastern Asia and the eastern of North America. 2020 was the warmest year recorded, while 2010 was the hottest year for parts of North America (≈34% of the territory). Approximately 60% of the Earth's land surface recorded a new maximum annual mean temperature after 2010. In terms of datasets comparison, ERA5 came the closest to the weather stations data regarding the hottest year ever recorded at various locations while Berkeley Earth and ERA5 indicated the highest correlations for the total number of record-breaking temperature events. Full text here: https://authors.elsevier.com/a/1fcQzcd3SFGzB (before Oct 8, 2022)
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The density and pattern of urban development can significantly influence the thermal environment in these areas. Several research studies have underlined the asymmetry of urban air temperature by using parameters such as an increase in mean temperature, decline in amplitude, and substantial phase delay in closely constructed buildings. This research examines urban morphological impacts on the city thermal climate using the data collected on air temperature. The data for this study were collected using iButton data loggers implemented across two different locations representing urban and suburban areas. Also, the study utilized one meteorological station to archive the climatic information in a rural area as a reference point. The data collection camping was held in 2019 during June, July, and August, which are considered the hottest months of the year at the case study location. The iButton data loggers were validated by calibrating the readings in a room chamber at the University Kbangsaan Malaysia (UKM) Malaysia. The study includes data analysis for the micro weather profile for all locations, including daytime, nighttime, and daily average air temperature. Results from the study indicated that daytime and nighttime temperature variation among urban and rural areas reached 3.6℃ and 6.3℃, respectively.
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The dry and hat weather in the southeast United States during the first seven months of 1986 caused record drought. The agricultural and hydrological perspectives of this drought are examined via a climatological time series. Late nineteenth and twentieth century climate data from the most severely affected areas indicate that from an agricultural perspective the beginning and middle of the 1986 growing season was by far the worst on record. On the other hand, from a hydrological perspective the drought was not of sufficient duration to stand out as such an extreme anomaly. The 1986 drought is part of a change in recent years from the wet weather of the 1960s and much of the 1970s. At this time, there is no evidence to suggest that this change is anything more than another in a series of climate fluctuations typical throughout the climate records of many areas.
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The paper demonstrates the relationship existing between the size of a village, town or city (as measured by its population), and the magnitude of the urban heat island it produces. This is accomplished by analyzing data gathered by automobile traverses in 10 settlements on the St. Lawrence Lowland, whose populations range from 1000 to 2 million inhabitants. The locations of these settlements effectively eliminate all non-urban climatic influences. The results are compared with previously published data.The analysis shows the heat island intensity under cloudless skies to be related to the inverse of the regional windspeed, and the logarithm of the population. A simple model is derived which incorporates these controls. In agreement with an extension of Summers' model the heat island appears to be approximately proportional to the fourth root of the population. With calm and clear conditions the relation is shown to hold remarkably well for North American settlements, and in a slightly modified form, for European towns and cities.
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