Article

The “Spectra” of the solar cycle and of data for Atlantic tropical cyclones

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

TROPICAL cyclones (including hurricanes) are significant climatic features which affect the South and East USA as well as areas of the western Atlantic, the Caribbean, and the Gulf of Mexico. Since they are considered to be a mechanism which limits the build-up of heat and energy in tropical regions1, cyclones are necessarily related to large scale circulation patterns which may be global in extent. Thus, if a relationship is to be found between solar activity and large scale meteorological phenomena, we may expect that it will evidence itself in analyses of data on cyclone occurrence and the length of the cyclone season. Here we report results of such a study, and provide evidence which is consistent with the hypothesis that a relationship exists between the solar cycle and the occurrence of Atlantic tropical cyclones.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... In terms of various types of time series analysis of instrumental surface air temperature data it seems that a majority of sources agree that decadal signals are present in the surface air temperature in North America (e.g., Dehsara and Cehak [1970], Curde [1974], Cohen and Sweetser [1975], Curde [1979,1981], Kane and Teixeira [1990], Curde [1993], Stevens and North [1996] and van Loon and Shea [1999] for the Northern Hemisphere (NH)), while only a minority (mainly Currie, but also Stevens and North [1996] and van Loon and Shea [1999]) also claim that there is evidence for a link between the signal Copyright 2001 by the American Geophysical Union. ...
... Teitelbaum and Bauer [1990] and Salby and Shea [1991] criticized the statistical support for this apparent link. Cohen and Sweetser [1975], Brown and John [1979], and Tinsley [1988] discuss decadal variability in the statistics of Atlantic storms. Curde [1996a] discusses decadal and bidecadal signals in storm statistics. ...
... Curde [1996a] discusses decadal and bidecadal signals in storm statistics. Cohen and Sweetser [1975] discussed bidecadal cyclone variability as well. Nastrom and Belmont [1980] showed an interesting change in the location of the jet stream above North America suggesting that it was coupled to the state of the solar cycle but, later, withdrew [Venne et al., 1983] While we shall come to agree with many of the above authors that decadal signals are present at statistically significant levels, throughout the world, we see little firm evidence in the literature that the signal should be due to the Sun. ...
Article
Full-text available
The geographical distribution and properties of the well-known 10-11 year signal in terrestrial temperature records is investigated. By analyzing the Global Historical Climate Network data for surface air temperatures we verify that the signal is strongest in North America and is similar in nature to that reported earlier by R. G. Currie. The decadal signal is statistically significant for individual stations, but it is not possible to show that the signal is statistically significant globally, using strict tests. In North America, during the twentieth century, the decadal variability in the solar activity cycle is associated with the decadal part of the North Atlantic Oscillation index series in such a way that both of these signals correspond to the same spatial pattern of cooling and warming. A method for testing statistical results with Monte Carlo trials on data fields with specified temporal structure and specific spatial correlation retained is presented.
... A cooling of the mid-latitutde North Atlantic since the 1950's has been repeatedly mentioned (Teich, 197 1 ;Rodewald, 1973;Perry, 1974;Wahl and Bryson, 1975). Milton (1974) and Cohen and Sweetser (1975) noted an increase of tropical cyclone frequency in the North Atlantic from 1910 to the 1950's, and Moran (1975) has related the subsequent reduction in Atlantic tropical cyclone frequency to decreased SST. Not all of the above claims are verified in our Figs. 2 and 3 and Table 1, possibly in part because our observations were limited to latitutdes equatorward of 30° N whereas other SST evaluations were of mid-latitutde data, or were averaged over a considerable range of latitudes. ...
... Periodicities of Atlantic tropical cyclones are quite.different, but are in part similar to the ones reported earlier by Cohen and Sweetser (1975) for a slightly different record. Their graph shows corollaries to our 9.2 and 7.9 year peaks. ...
Article
Variations in the annual frequency of tropical cyclones in the North Atlantic and of tropical cyclones and temporales in the Eastern North pacific are studied in relation to sea surface temperature (SST), sea level pressure (SLP), and vertical wind shear, the observation period common to most parameters being 1911–72. Both oceans exhibit a secular SST increase until the 1950's. Tropical cyclone frequency has a strong negative correlation with SLP in the realm of the subtropical highs, but only a weak negative one with SST in the areas of common storm occurrence. Temporales are positively correlated with SLP but negatively with SST and tropical storms in the Pacific. A minimum threshold of area-averaged SST and a maximum threshold of vertical wind shear can be specified for one or more tropical cyclones to occur. Principal component analysis was performed on indicative time series from both oceans. As prominent constituents of the first principal component, Pacific SLP, temporales, and Atlantic tropical cyclones have factor loadings of one sign, while Pacific tropical cyclones have the opposite sign. The second principal component is made up primarily of parallel SST variations in both oceans. Spectral analysis reveals a coupling of SLP variations over the two oceans around 33–34 and 5.5 years. In the Atlantic, SLP minimum precedes the SST maximum at about 12.5 years. Maxima of Pacific SLP and temporales and minima of Ecuador/Peru SST and Atlantic tropical cyclone occurrence broadly coincide at a common frequency of about 8 years. At the 13.6–14.8 year time scale in the Pacific, minima of Ecuador/Peru SST, and minima of tropical cyclone frequency and maxima of SLP in the North Pacific are approximately synchronous. Spectral analysis details the time scale of spatial linkages borne out by linear correlation and principal component analysis. DOI: 10.1111/j.2153-3490.1979.tb00879.x
... A cooling of the mid-latitutde North Atlantic since the 1950's has been repeatedly mentioned (Teich, 197 1 ;Rodewald, 1973;Perry, 1974;Wahl and Bryson, 1975). Milton (1974) and Cohen and Sweetser (1975) noted an increase of tropical cyclone frequency in the North Atlantic from 1910 to the 1950's, and Moran (1975) has related the subsequent reduction in Atlantic tropical cyclone frequency to decreased SST. Not all of the above claims are verified in our Figs. 2 and 3 and Table 1, possibly in part because our observations were limited to latitutdes equatorward of 30° N whereas other SST evaluations were of mid-latitutde data, or were averaged over a considerable range of latitudes. ...
... Periodicities of Atlantic tropical cyclones are quite.different, but are in part similar to the ones reported earlier by Cohen and Sweetser (1975) for a slightly different record. Their graph shows corollaries to our 9.2 and 7.9 year peaks. ...
Article
Variations in the annual frequency of tropical cyclones in the North Atlantic and of tropical cyclones and temporales in the Eastern North pacific are studied in relation to sea surface temperature (SST), sea level pressure (SLP), and vertical wind shear, the observation period common to most parameters being 1911–72.Both oceans exhibit a secular SST increase until the 1950's. Tropical cyclone frequency has a strong negative correlation with SLP in the realm of the subtropical highs, but only a weak negative one with SST in the areas of common storm occurrence. Temporales are positively correlated with SLP but negatively with SST and tropical storms in the Pacific. A minimum threshold of area-averaged SST and a maximum threshold of vertical wind shear can be specified for one or more tropical cyclones to occur.Principal component analysis was performed on indicative time series from both oceans. As prominent constituents of the first principal component, Pacific SLP, temporales, and Atlantic tropical cyclones have factor loadings of one sign, while Pacific tropical cyclones have the opposite sign. The second principal component is made up primarily of parallel SST variations in both oceans.Spectral analysis reveals a coupling of SLP variations over the two oceans around 33–34 and 5.5 years. In the Atlantic, SLP minimum precedes the SST maximum at about 12.5 years. Maxima of Pacific SLP and temporales and minima of Ecuador/Peru SST and Atlantic tropical cyclone occurrence broadly coincide at a common frequency of about 8 years. At the 13.6–14.8 year time scale in the Pacific, minima of Ecuador/Peru SST, and minima of tropical cyclone frequency and maxima of SLP in the North Pacific are approximately synchronous. Spectral analysis details the time scale of spatial linkages borne out by linear correlation and principal component analysis.
... Earlier, CUR39 reported both signals in 59 records from South Afnca alone. Cohen and Sweetser's (1975) conjecture that the long-period peak in cyclone occurrence could have its origin in the x 2 0 to ~2 2 ...
... NOAA (1990) has published the number of North Atlantic cyclones from 1871-1986. Following Cohen and Sweetser (1975), the writer has also constructed the length of the cyclone season in months-counted as the number of months from the month of the first cyclone to the month of the last, inclusive. ...
Article
Maximum entropy spectrum analysis of two yearly sampled time series for North Atlantic cyclones (length of cyclone season in months and number of cyclones per season) yields evidence for two peaks with periods 18 and 10 years. They are identified as the luni-solar 18.6-year, Mn, and 10-11-year solar cycle, Sc;, signals in climate. Amplitudes of both terms are highly non-stationary with respect to time, although the polarity of both Mn wavetrains experienced an abrupt 180° phase change early in this century. On average the two terms account for 20 per cent of total variance in the raw series, in which the Nyquist frequency is 0.5cpy. When power in the raw series from 0.125cpy (period of 8 years) to the Nyquist is filtered out prior to analysis, and the variance contribution of the signals to filtered data compared over a common bandwidth of 30 to 8 years, their variance contribution increases dramatically to a mean of 82 per cent. Such experiments have been carried out for thousands of climate records with similar results; thus, the spectrum of climate from 30 to 8 years has turned out to be strongly signal-like rather than noise-like as radically assumed by statisticians and mathematicians the past 70 years. The results corroborate and extend analysis of the same data by Cohen and Sweetser, except, that they mistakenly conjectured that the long-period term could be induced by the 20-22-year Hale magnetic cycle on the Sun.
... S olar act ivity, volcanic eruptions, and changes in the thermohaline circulation of the North Atlantic are currently under investigation for their impacts on tropical cyclones. Some studies performed on solar activity (Cohen and Sweetser 1974;Liu et al. 2001) indicate that the sunspot cycle may influence tropical cyclones due to fluctuations in solar irradiance, but this theory is still being debated. ...
... number of intense hurricanes in the At lantic basin. Le hmiller et al. (1997) describe a landfall probability model for the southeastern U.S. coast. Forecasts of hu rricane act ivity along the coast in areas smaller than large regions (i.e., smaller t han Gulf Coast or SE Coast ) are being experimented with in some climate prediction laboratories.Cohen and Sweetser (1974) describe an apparent relationship between the solar cycle and Atlantic tr opical cyclones.Liu et al. (2001) demonst rates that the most active period for landfalls in the Guangdong province of China over a 1000+ year period of record occurred during the Maunder Minimum, when sunspot numbers were near zero.Elsner and Kavlakov (2001, in r ...
Article
Hurricane climate research is based on data spanning the last 100 years or so. To better understand rare but potentially catastrophic hurricane events it is helpful to have longer records. Records from historical archives are available, but they need to be collated and edited. Efforts to collate U.S. tropical cyclone information from the first half of the 19th Century using a Geographic Information System (GIS) have been conducted in this research. The Historical Hurricane Impact Tool (HHIT) is based on Environmental Systems Research Institute’s (ESRI) ArcView GIS 3.1. Statements concerning coastal and near-coastal impacts are reproduced within map callout boxes. The callout boxes point to the geographic location of the documented information. Map layers are used for different archival sources. The HHIT, which is available in hardcopy format and will be online in the near future via an internet map server, can be used by scientists, emergency managers, and the general public to better estimate the risk of a hurricane catastrophe. The U.S. hurricane database (“Best-Track”) was recently extended from 1871 back to 1851 through the work of NOAA’s Atlantic Hurricane Reanalysis Project. In addition, the previously mentioned Historical Hurricane Impact Tool (HHIT) has been utilized to collate and list recorded U.S. hurricanes back to the year 1800. The combination of NOAA’s “Best-Track” data back to 1851 and the HHIT collated hurricane list back to 1800 provide an unprecedented look at U.S. hurricane activity since the beginning of the industrial revolution. This research also examines U.S. (major) hurricanes over four 50-year epochs, and then further examines regional trends in U.S. hurricanes. Seasonal distributions are similar across epochs. The earliest epoch contains the greatest ratio of major hurricanes to all U.S. hurricanes. Each epoch is further divided into three separate regions, and hurricane landfalls in Florida and the East Coast region are found to have an inverse relationship. Furthermore, the relationship between climate variables such as ENSO, the NAO, the PDO, and U.S. hurricanes appears to be different in the first epoch (1801-1850) than in the other three epochs (1851-2000). The relationships noted are robust to changes in sample size. A physical explanation for the noted trend is presented in a later chapter. Other climate influences on U.S. hurricanes, including volcanic eruptions and sunspots, are explored for effects on landfall counts.
... The most obvious evidence for such variation is the occurrence and disappearance of sunspots. Because of such changes in solar activity, total solar irradiance varies over different timescales, ranging from seconds to centuries [9][10][11]. We thus ask whether multi-scale variations in solar irradiance induce climate oscillations on various time scales. ...
... When the IMFs have energy above the upper bound and below the lower bound, they are considered to contain information at that selected confidence level. In Figure 17, the black × symbols are the average period and corresponding energy for the 11 IMFs of the minimum air temperature, the blue + symbols are for the 12 IMFs of the maximum air temperature, the red * symbols are for the 11 IMFs of mean air temperature, and the pink stars are for the 11 1-year cycles of changes in the air temperature at the 95% confidence level, they do not correlate to the solar variability. Therefore, the test further confirms the irrelevant relationship between air temperature changes and solar variation on short and medium time scales. ...
Article
Full-text available
The contemporary science of climate change is increasingly focusing on the temporal and spatial characteristics of temperature oscillations and determining possible underlying causes. In particular, the effect of variations in solar irradiance on the variability of the climate remains a hot topic of debate. Most studies focus on the effects of solar variation on the Earth’s climate on long time scales. This study presents the responses of regional climates to solar variations on shorter time scales using two datasets: one for the air temperature in Nanjing and the Greenwich sunspot number, and the other for the air temperature in Shijiazhuang and the United States sunspot number. Employing empirical mode decomposition, both the 11-year quasi-period of the sunspot number and similar periods including approximately 5.5- and 10.5-year cycles of the air temperature in Nanjing and Shijiazhuang are obtained. However, correlation analysis of similar periodic components for the sunspot number and air temperature indicates that changes in the air temperature on short and medium time scales are not linked to solar variations. This is further confirmed by a test of whether a mode component is a stochastic noise signal. Many shorter periods are also found at the 95% confidence level; in particular, the 3.1-year period of the Nanjing air temperature coincides with a previously obtained empirical result. Moreover, no temperature variations on shorter time scales correlate with solar variability. Keywordsclimate change–temperature multi-scale variations–solar cycle
... So far, it is believed that the intensity of a TC or the active level of TCs during a season cannot be attributed to a single factor, such as the global warming or other environment change. Cohen and Sweetser (1975) suggested the correlation between solar cycle and Atlantic TC activities from the similarities in the spectra for the 7-yr running mean TC number in North Atlantic, the 7-yr running mean length of the cyclone season, and the 12-month running mean sunspot numbers. Ivanov (2007) later confirmed the correlation between magnetic storms and TCs in the Atlantic, and found that the linear correlation coefficient changed in different regions from positive to negative values. ...
Preprint
Studies on Sun-climate connection have been carried out for several decades, and almost all of them focused on the effects of solar total irradiation energy. As the second major terrestrial energy source from outer space, the solar wind energy flux exhibits more significant long-term variations. However, its link to the global climate change is rarely concerned and remain a mystery. As a fundamental and important aspect of the Earth's weather and climate system, tropical cyclone activity has been causing more and more attentions. Here we investigate the possible modulation of the total energy flux input from the solar wind into the Earth's magnetosphere on the global tropical cyclone activity during 1963--2012. From a global perspective, the accumulated cyclone energy increases gradually since 1963 and start to decrease after 1994. Compare to the previously frequently used parameters, e,g., the sunspot number, the total solar irradiation, the solar F10.7 irradiation, the tropical sea surface temperature, and the south oscillation index, the total solar wind energy flux input exhibits a better correlation with the global tropical cyclone activity. Furthermore, the tropical cyclones seem to be more intense with higher geomagnetic activities. A plausible modulation mechanism is thus proposed to link the terrestrial weather phenomenon to the seemly-unrelated solar wind energy input.
... However, one aspect that remains a gray area is how solar variability affects TC activity. Cohen and Sweetser (1975) directly looked into a possible relationship between TCs and solar activity. The authors did a spectral analysis of smoothed TC count, TC season length (7-year running averages) for the Atlantic basin, and sunspot number (SSN) (12-month running average) data and suggested a possible relationship between Atlantic TC activity and solar cycle. ...
Article
Full-text available
The current study explores the relationship between solar variability and tropical cyclone (TC) activity using sunspot number (SSN) and TC best‐track data as respective proxies. We have considered six regions of the globe, for example, EP: Eastern Pacific, NA: North Atlantic, NI: North Indian, SI: South Indian, SP: South Pacific, and WP: Western Pacific. The results show strong anti‐correlation between yearly TC activity and yearly SSN while considering their 11‐year moving averages. This behavior is consistent for TC counts as well as accumulated cyclone energy. However, this is true only for the North Atlantic region. Overall, when we consider all regions together, more TCs (in terms of counts) are observed during lower solar activity periods (SSN < 50) as compared to higher solar activity conditions (SSN > 100). However, the yearly rates remain more or less similar. On the other hand, extreme TC events with a maximum wind speed of 137 knots and higher (category 5) are most likely to occur during the declining phase of a solar cycle and least likely to occur during the ascending phase or the maximum phase. Although solar activity levels are similar during the declining and ascending phases, the yearly occurrence rate is nearly double in the declining phase (1.123) as compared to that in the ascending phase (0.625).
... The in-phase correlation found between the solar cycle and offseason typhoons is opposite to that of the out-of-phase correlation reported in previous studies [34][35][36] between the solar cycle and in-season typhoons. For example, Hung 36 found that the number of in-season typhoons (during the boreal summer and fall) over the western North Pacific decreased (increased) during active (inactive) periods of the solar cycle. ...
Article
Full-text available
The occurrence of super typhoons outside the normal typhoon season can result in devastating loss of life and property damage. Our research reveals that the 11-year solar cycle can affect the incidence of these off-season typhoons (from November to April) in the western North Pacific by influencing sea surface temperature (SST) through a footprint mechanism. The solar cycle, once amplified by atmospheric and ocean interactions, generates a noticeable SST footprint in the subtropical North Pacific during winter and spring, which eventually intrudes into the tropical central Pacific and affects the atmospheric conditions, resulting in an increase or decrease in the occurrence of super typhoons during active or inactive solar periods. This mechanism has become more effective since the Atlantic Multi-decadal Oscillation (AMO) shifted to a warm phase in the 1990s, intensifying the subtropical Pacific couplings. An example of this type of off-season super typhoon during an active solar period is Typhoon Haiyan in 2013. By incorporating information about the solar cycle, we can anticipate the likelihood of super typhoon occurrences, thus improving decadal disaster preparation and planning.
... The variation of TCs is closely related to the global and regional atmosphere-ocean systems, such as solar activity, Pacific Decadal Oscillation (PDO), and El Niño-Southern Oscillation (ENSO) (Sweetser and Cohen, 1975;Mei and Xie, 2015;Mei and Xie, 2016). The variation of solar activity and PDO is negatively correlated with the number and intensity of TCs (Hodges and Elsner, 2011;Kavlakov, 2005;Pérez-Peraza et al., 2008;Mao and Jin, 1996). ...
Article
Among all marine hazards, storm surges cause the most severe damage, and East Asia is one of the regions in the world most affected by tropical cyclones (TCs). With the increase in global mean temperature, the future changes of tropical cyclone (TC) activities are of great concern in East Asian countries. However, due to the inconsistency among different TC datasets, there is no uniform understanding of the spatial and temporal distribution and trends of TC activities in the eastern sea area of China (ESAC). In this study, all TC wind fields affecting ESAC during 1949–2019 were calculated using the Fujita-Takahashi formula, and a new TC dataset with a spatial resolution of 0.1° × 0.1° was thus obtained. Based on this dataset, the spatial-temporal variations of TC activity were analyzed. Three stages (1949–1967, 1968–1993, 1994–2019) of TC activities in ESAC can be identified using Mann Kendall Trend Test, which is closely related to El Niño-Southern Oscillation, sunspot activity, and Pacific Decadal Oscillation. A comparison of the accumulative number and duration of TCs in the three stages shows increasing trend toward the coasts and an northward. To address the issue of shelf storm deposition records on ESAC, we compared the published storm depositional records retrieved from several cores with typhoon impact data from the same sites based on the dataset of this study. We found that the preservation potential of the storm deposition record on ESAC ranged from 8% to 33%, with a high preservation potential in shallow water. These findings reveal the distribution and variability of TC impacts, which can be used to provide a scientific basis for disaster prevention and mitigation planning and adjustment of key coastal protection zones, as well as to evaluate the value of marine sedimentary records better.
... Theoretically this change may be subtle and difficult to detect. Cohen and Sweester (1975) examined the variations in the number of Atlantic hurricanes as a function of time using maximum entropy power spectrum. A prominent peak in number of cyclones occurs at 11.3 years. ...
... Solar activity variations often cause irradiance changes, geomagnetic fields and atmospheric circulation (Cohen and Sweetser, 1975), and it is one of the key factors that drive global atmospheric circulation and regional climate change (Berger and Loutre, 1991). There is a coupling relationship between solar irradiance and DFD with changes in the thermal state of the atmosphere (Rind, 2002), and ENSO events have a significant impact on the Asian monsoon anomaly and natural disasters in China (Alexander et al., 2002;Wu and Yan, 2014). ...
Article
Full-text available
Drought and flood disasters (DFD) are the most important natural disasters in the Indian monsoon (IM) region, and often occur in the same year. This makes it difficult to accurately study the characteristics of DFD using the evaluation grades of disasters. Based on the statistical analysis of historical drought and flood data in Yunnan Province, combined with anomaly accumulation values, sliding t tests and wavelet analyses, the spatial–temporal characteristics and the possible dynamic mechanisms of the DFD in Yunnan Province are analysed during the past 620 years. The results show that the frequency of flood disasters in Yunnan Province was slightly higher than that of drought disasters, and disaster frequency has gradually increased over the past 620 years, especially after 1750 AD. The variations characteristics of the drought and flood index (DFI) have 2 ~ 10 year quasi‐periodic signal in the east and west regions of the Yunling‐Ailao Mountains, and they are consistent with the environmental records of tree rings and lacustrine deposits in the region. The DFD of the IM region may be influenced mainly by solar activity and El Niño‐Southern Oscillation (ENSO) on a century scale, and frequent human activities enhance the impact of DFD, especially in the east region of the Yunling‐Ailao Mountains. The results provide a method to further understand the mechanism and trends of drought and flood disasters in the monsoon region on a century scale.
... From these results, further studies were established during the 20 th century to find out if similar results could be obtained in other settings, in different time frames. These include moderate positive correlations obtained by Cohen & Sweetser (1975) in the North Atlantic and by Sanchez-Sesma (2006) using records of typhoons in Japan from 700 AD. Others use the geomagnetic and cosmic ray indices (i.e AA index, Mg II index) for the depiction in which same weak to moderate positive correlations were attained with severe cyclonic storms in the Bay of Bengal & Arabian Sea (Sudhir & Christiana, 2012), with the cyclonic activity the North Indian Ocean during 22 nd solar cycle (Selvaraj & Uma, 2011) and high inverse relationships were obtained in the Western North Pacific (Kavlakov, 2011). ...
Research
This research discusses the relationship between solar activity, represented by the sunspot number (SSN), and landfalling tropical cyclone frequency (LTCF) in the Philippines. It has found that there is a weak insignificant overall relationship between SSN and LTCF in the Philippines, taking into account both the entire solar cycle and its extremes (minimum and maximum), which were done in both annual and peak season approaches. An inverse relationship exists between SSN and LTCF during sunspot minimum. On the other hand, a direct correlation exists during sunspot maximum. Stronger correlations were obtained in the peak season approaches which supports the notion of considering only the peak months of the tropical cyclone season in determining the correlation between the two variables. It has also found that either the solar cycle is at its minimum or maximum, the variation in the LTCF doesn't affect much by the SSN. The effect of the extremes of the El Niño Southern Oscillation (ENSO) to the relationship between SSN and LTCF was also examined in this study, with a direct correlation obtained during La Niña years and inverse during El Niño years, but of weak and insignificant affair.
... So far, it is believed that the intensity of a TC or the active level of TCs during a season cannot be attributed to a single factor, such as the global warming or other environment change. Cohen and Sweetser (1975) suggested the correlation between solar cycle and Atlantic TC activities from the similarities in the spectra for the 7-yr running mean TC number in North Atlantic, the 7-yr running mean length of the cyclone season, and the 12-month running mean sunspot numbers. Ivanov (2007) later confirmed the correlation between magnetic storms and TCs in the Atlantic, and found that the linear correlation coefficient changed in different regions from positive to negative values. ...
Article
Full-text available
Studies on Sun-climate connection have been carried out for several decades, and almost all of them focused on the effects of solar total irradiation energy. As the second major terrestrial energy source from outer space, the solar wind energy flux exhibits more significant long-term variations. However, its link to the global climate change is rarely concerned and remain a mystery. As a fundamental and important aspect of the Earth's weather and climate system, tropical cyclone activity has been causing more and more attentions. Here we investigate the possible modulation of the total energy flux input from the solar wind into the Earth's magnetosphere on the global tropical cyclone activity during 1963--2012. From a global perspective, the accumulated cyclone energy increases gradually since 1963 and start to decrease after 1994. Compare to the previously frequently used parameters, e,g., the sunspot number, the total solar irradiation, the solar F10.7 irradiation, the tropical sea surface temperature, and the south oscillation index, the total solar wind energy flux input exhibits a better correlation with the global tropical cyclone activity. Furthermore, the tropical cyclones seem to be more intense with higher geomagnetic activities. A plausible modulation mechanism is thus proposed to link the terrestrial weather phenomenon to the seemly-unrelated solar wind energy input.
... However, no description of a physical mechanism was put forward. [6] performed a spectral analysis of North Atlantic hurricane frequency from 1871-1973 with sunspot numbers from 1750-1963. Of their more interesting results were 11-year periodicities in both the annually-averaged sunspot totals and seasonal hurricane counts at 11.0 and 11.3 years, respectively. ...
Article
Full-text available
The authors define a spatio-statistical response of hurricane frequency to the solar cycle. Previous research indicates reduced (increased) hurricane intensities and frequency in the western (eastern) tropical Atlantic. However, no formal quantitative relationship has been spatially established between hurricane frequency and solar activity. The authors use a Bayesian hierarchical space–time model, an increasingly popular approach due to its advantage in facilitating regression modeling of space–time phenomena in the context of large data sets. Regional hurricane frequency over the period 1866–2010 is examined in response to September sunspot number (SSN) while controlling for other relevant climate factors. The response features a 13 % reduction in probability of annual hurricane occurrence for southeastern Cuba, the southern Bahama islands, Haiti, and Jamaica when the SSN is 80 sunspots. In contrast, hurricane risk in regions of the southeastern Atlantic is predicted to increase by 73 % when the SSN is 160 sunspots. The model can be ported to explore other relationships over contiguous space.
... The efficiency of this engine is largely controlled by the oceanographic and atmospheric conditions in which the storm is forming and through which it translates. Instrumental observations suggest that the life cycle (genesis, intensity, and track) of a hurricane is influenced by a few key climate systems: the El Niño-Southern Oscillation (ENSO) [Gray, 1984], the West African Monsoon [Bell and Chelliah, 2006], solar variability [Cohen and Sweetser, 1975], sea surface temperatures [Emanuel, 2005;Webster et al., 2005], volcanic aerosols [Elsner and Kara, 1999], and the Atlantic multi-decadel oscillation [Goldenberg et al., 2001]. Yet, given the short length of reliable instrumental records (>1850 A.D.), the extent to which these climatic forcings influence or even dominate hurricane behavior on geologic timescales remains poorly known. ...
Article
Full-text available
Available overwash records from coastal barrier systems document significant variability in North Atlantic hurricane activity during the late Holocene. The same climate forcings that may have controlled cyclone activity over this interval (e.g., the West African Monsoon, El Niño-Southern Oscillation (ENSO)) show abrupt changes around 6000 yrs B.P., but most coastal sedimentary records do not span this time period. Establishing longer records is essential for understanding mid-Holocene patterns of storminess and their climatic drivers, which will lead to better forecasting of how climate change over the next century may affect tropical cyclone frequency and intensity. Storms are thought to be an important mechanism for transporting coarse sediment from shallow carbonate platforms to the deep-sea, and bank-edge sediments may offer an unexplored archive of long-term hurricane activity. Here, we develop this new approach, reconstructing more than 7000 years of North Atlantic hurricane variability using coarse-grained deposits in sediment cores from the leeward margin of the Great Bahama Bank. High energy event layers within the resulting archive are (1) broadly correlated throughout an offbank transect of multi-cores, (2) closely matched with historic hurricane events, and (3) synchronous with previous intervals of heightened North Atlantic hurricane activity in overwash reconstructions from Puerto Rico and elsewhere in the Bahamas. Lower storm frequency prior to 4400 yrs B.P. in our records suggests that precession and increased NH summer insolation may have greatly limited hurricane potential intensity, outweighing weakened ENSO and a stronger West African Monsoon—factors thought to be favorable for hurricane development.
... Cohen and Sweetser [9] performed a spectral analysis of North Atlantic hurricane frequency from 1871 to 1973 with sunspot numbers from 1750 to 1963. Of their more interesting results were 11-year periodicities in both the annually averaged sunspot totals and seasonal hurricane counts at 11.0 and 11.3 years, respectively. ...
Article
Full-text available
The authors define the spatial response of hurricanes to extremes in the solar cycle. Using an equal-area hexagon tessellation, regional hurricane counts are examined during the period 1851–2010. The response features fewer hurricanes across the Caribbean, Gulf of Mexico, and along the eastern seaboard of the United States when sunspots are numerous. In contrast fewer hurricanes are observed in the central North Atlantic when sunspots are few. The sun-hurricane connection is as important as the El Niño Southern Oscillation toward statistically explaining regional hurricane occurrences.
... This trend may be changing in the middle 1990s as noted in Kimberlain and Elsner (1998). More recently, Cohen and Sweetser (1975) examined the relationship for the entire North Atlantic basin. They E L S N E R E T A L . ...
Article
The annual record of hurricane activity in the North Atlantic basin for the period 1886-1996 is examined from the perspective of time series analysis. Singular spectrum analysis combined with the maximum entropy method is used on the time series of annual hurricane occurrences over the entire basin to extract the dominant modes of oscillation. The annual frequency of hurricanes is modulated on the biennial, semidecadal, and near- decadal timescales. The biennial and semidecadal oscillations correspond to two well-known physical forcings in the local and global climate. These include a shift in tropical stratospheric winds between an east and west phase (quasi-biennial oscillation (QBO)) and a shift in equatorial Pacific Ocean temperatures between a warm and cold phase (El Nino-Southern Oscillation (ENSO)). These climate signals have previously been implicated in modulating interannual hurricane activity in the North Atlantic and elsewhere. The near-decadal oscillation is a new finding. Separate analyses on tropical-only (TO) and baroclinically enhanced (BE) hurricane frequencies show that the two components are largely complementary with respect to their frequency spectra. The spectrum of TO hurricanes is dominated by timescales associated with ENSO and the QBO, while the near-decadal timescale dominates the spectrum of BE hurricanes. Speculations as to the cause of the near-decadal oscillation of BE hurricanes center on changes in Atlantic SSTs possibly through changes in evaporation rates. Specifically, cross- correlation analysis points to solar activity as a possible explanation. ''The hurricanes . . . used to come every seven years, or every five years, but they have become more frequent following the settlement of the Antilles.''
... Solar-related decadal and interdecadal changes are ubiquitous in climate records of land and sea surface temperatures [e.g., Newell et al., 1989;•4llen and Smith, 1994;Mann and Park, 1994], U.S. drought [e.g., Mitchell et al., 1979], rainfall [e.g., Curtie and O'Brien, 1988;Seleshi et al., 1994;Perry, 1994], forest fires [e.g., •4uclair, 1992], and cyclones [e.g., Cohen and Sweester, 1979]. However, the limited geographical coverage of ature response to changing solar irradiance and estimates for depths to which the temperature response penetrates into the upper ocean on both timescales. ...
Article
Full-text available
By focusing on time sequences of basin-average and global-average upper ocean temperature (i.e., from 40øS to 60øN) we find temperatures responding to changing solar irradiance in three separate frequency bands with periods of >100 years, 18-25 years, and 9-13 years. Moreover, we find them in two different data sets, that is, surface marine weather observations from 1990 to 1991 and bathythermograph (BT) upper ocean temperature profiles from 1955 to 1994. Band-passing basin-average temperature records find each frequency component in phase across the Indian, Pacific, and Atlantic Oceans, yielding global-average records with maximum amplitudes of 0.04 ø _+ 0.01øK and 0.07 ø _+ 0.01øK on decadal and interdecadal scales, respectively. These achieve maximum correlation with solar irradiance records (i.e., with maximum amplitude 0.5 W m -2 at the top of the atmosphere) at phase lags ranging from 30 ø to 50 ø. From the BT data set, solar signals in global-average temperature penetrate to 80-160 m, confined to the upper layer above the main pycnocline. Operating a global-average heat budget for the upper ocean yields sea surface temperature responses of 0.01ø-0.03øK and 0.02ø-0.05øK on decadal and interdecadal scales, respectively, from the 0.1 W m -2 penetration of solar irradiance to the sea surface. Since this is of the same order as that observed (i.e., 0.04ø-0.07øK), we can infer that anomalous heat from changing solar irradiance is stored in the upper layer of the ocean.
... NE America (Fig. 3c and Table 3) comprises the only other major area in which indications of a solar cycle in MSL have been obtained, all bins along the east coast of the USA showing an effect approximately in phase with the sunspot cycle. While 11-yr cycles have been reported in other climatic variables in this area (such as the number of tropical cyclones and the length of the cyclone season, see Cohen & Sweetser 1975), the amplitude of the observed effect (Fig. 3c) is incapable of being described by SLP changes analogousto those discussed above for Europe (Parker 1976: Kelly & Jones 1983. A variance analysis such as that made for Europe shows the American data to contain a strong signal centred at a period of 12.5 yr rather than 10.6 yr, and an inspection of peaks in the MSL time series shows most of the effect to be correlated with the interannual variation in river runoff for the area as reported by Meade & Emery (1971). ...
Article
Tide gauge records from throughout the world have been examined for evidence of the 11-yr solar cycle in mean sea-level (MSL). In Europe an amplitude of 10–15mm is observed with a phase relative to the sunspot cycle similar to that expected as a response to forcing from previously reported solar cycles in sea-level air pressure and winds. At the highest European latitudes the MSL solar cycle is in antiphase to the sunspot cycle while at mid-latitudes it changes to being approximately in phase. Elsewhere in the world there is no convincing evidence for an 11-yr component in MSL records.
... It should be mentioned that other workers have suggested correlations between the sunspot cycle and atmospheric conditions over the North Atlantic such as the occurrence of tropical cyclones, sea level pressure, sea surface temperatures, and average sea levels [Cohen and Sweetser, 1975;Kelly, 1977;Colebrook, 1976;Muir, 1977]. Comparison of these North Atlantic data including the Iceland ice index together with our Newfoundland data shows similar longterm trends. ...
Article
Full-text available
Sea ice conditions off the east coast of Newfoundland for the last 130 years are presented, forming what is believed to be the longest ice record for the Northwestern Atlantic. Because of differences in how these data were originally collected, the series is divided into two sets, before and after 1920. Times series for solar activity and air temperature at St. John's have also been compiled and correlation coefficients between the sea ice extent and solar activity are discussed in the context of the Iceland ice index and recent findings in the atmosphere-ocean-ice system in the northern hemisphere. The association with the quasi-biennial oscillation (QBO) and the similarity with the fluctuating rends of sea levels, sea surface temperatures, and storms in the North Atlantic are noted. Predictions for the sea ice extent are made for the next few years based on the relationship with solar activity. y
Book
The Earth's climate system depends entirely on the Sun for its energy. Solar radiation warms the atmosphere and is fundamental to atmospheric composition, while the distribution of solar heating across the planet produces global wind patterns and contributes to the formation of clouds, storms, and rainfall. The Sun's Influence on Climate provides an unparalleled introduction to this vitally important relationship. This accessible primer covers the basic properties of the Earth's climate system, the structure and behavior of the Sun, and the absorption of solar radiation in the atmosphere. It explains how solar activity varies and how these variations affect the Earth's environment, from long-term paleoclimate effects to century timescales in the context of human-induced climate change, and from signals of the 11-year sunspot cycle to the impacts of solar emissions on space weather in our planet's upper atmosphere. Written by two of the leading authorities on the subject, The Sun's Influence on Climate is an essential primer for students and nonspecialists alike.
Article
The purpose of this study is to propose a documentation on the monsoon flow in the North of the Mozambica Channel and in particular the modes of apparition of this monsoon flow. As a matter of fact, the meridian wind at the 850 hPa pressure levels, issued from the data analysis of the European centre ECWMM has been specifically studied. In a first setting, the superposition of the average and the standard deviation of the meridian wind permits, on one hand, to see the modulation and the significativity of the monsoon flow in the North of the Channel, and on the other hand, to define the strong variability of this flow. This zone is located between the longitudes 39°- 44° E and the latitudes 0°-10°S. The spectral analysis by using the Fast Fourier Transform (FFT) and the Maximum Entropy Method (MEM) has been made in the second instance in order to highlight the 3 modes of the Cross-equatorial monsoon flows: 6-10 days, 15-25 days and 25-45 days.
Article
Each year, approximately 210 000 American men are diagnosed with prostate cancer and 41 800 die from the disease — numbers roughly equal to the incidence and mortality for breast cancer in women. Prostate cancer usually shows no symptoms in early stages, when it is most treatable. To detect the disease early, physicians usually recommend that every man 50 years and older have an annual examination consisting of a digital rectal examination and a prostate specific antigen (PSA) blood test. Conventional treatments such as surgical removal of the diseased prostate, external beam radiation, radioactive seed therapy and hormonal and/or chemotherapy treatment regimens are most successful for early stage prostate cancer and have limited effectiveness in advanced stages of the disease. For this reason, accurate staging of primary and recurrent prostate cancer is mandatory for proper therapeutic decisions. Nuclear medicine imaging of prostate cancer using the radiolabelled monoclonal antibody, 111In-capromab pendetide, has proven useful in newly diagnosed patients with biopsy-proven prostate cancer in which there is high suspicion of distant metastatic disease and for prostatectomy patients with rising PSA levels and/or suspicion of recurrence or metastatic disease. Although not intended as a screening tool, it is used in conjunction with standard evaluation procedures for improved staging of patients. The monoclonal antibody, designated 7E11-C5, binds the prostate specific membrane antigen (PSMA) expressed on the surface of prostate epithelial cells and up-regulated in tumour cells. The sensitivity and specificity for prostate cancer involved lymph node detection has been reported as 62 to 75% and 72 to 86%, respectively, compared with sensitivities of 4% and 15% for computerised tomography and magnetic resonance imaging, 111In-capromab pendetide imaging has proven to be an accurate, non-invasive tool for detecting and staging sites of recurrence in the post-prostatectomy patient as well as metastatic sites in the patient with newly diagnosed prostate cancer.
Article
Previous studies have identified possible linkages between solar activity and tropical cyclone activity in the United States and Caribbean. This study used historical typhoon records dating back to the early 1700s, the Central Weather Bureau records (since 1897), and the JTWC (Joint Typhoon Warning Center) (since 1945) to investigate the relationship between solar activity and the number of typhoons in Taiwan. The results show that a negative relationship exists between solar activity and typhoon frequency in Taiwan at decadal time scales. Fewer typhoons occurred during the periods 1770 to 1790 and 1930 to 1960, with a higher number of typhoons occurring during 1810 to 1830 and 1870 to 1930. A likely mechanism for the relationship is that more intense solar activity can warm the lower stratosphere and the upper troposphere through absorption of solar radiation by atmospheric ozone. This would decrease the convective available potential energy and reduce the frequency of typhoon occurrence. As a consequence, fewer typhoons form over the western North Pacific with fewer affecting Taiwan. The negative correlation between solar activity and the number of typhoons affecting Taiwan is important to understand changes in the frequency and behavior of typhoons resulting from climate change.
Article
Full-text available
The solar cycle (quantified by sunspot number) has been suggested to be a contributing factor in tropical cyclone frequency and/or intensity, with an active sun (more sunspots) causing heightened activity. Here we analyze the relationship between North Atlantic tropical cyclones and extreme minimum and maximum sunspot years. Sunspot numbers are tested with other common predictors to determine their utility in seasonal tropical cyclone prediction. It is found that the complete sunspot cycle is not consistently related to basin-wide tropical cyclone activity (r = 0.024). However, sunspot extreme years show stronger correlations, with minimum years having the highest correlations to tropical cyclone frequency. Minimum sunspot years and the AMO index can combine to explain more than 54 percent of the variations in total tropical cyclones and nearly 46 percent of the variation in tropical cyclone days. Solar cycle extremes should be considered for more accurate seasonal tropical cyclone predictions.
Article
THE dominant large scale phenomena determining the climate of the North Atlantic Ocean are the current systems of the Gulf Stream and the North Atlantic Drift as well as the pattern of atmospheric circulation associated with the semi-permanent centres, the Iceland low and the Azores high. Recently, three long time series of data have become available which throw some light on the interactions between these ocean-atmosphere systems and which appear to indicate the importance of advective processes, as opposed to upwelling, in determining long term variations in the surface temperature of the ocean.
Article
The mean latitude at which surface depressions cross a given longitude in the N.E. Atlantic/N.W. Europe sector during the winter months of the year has been found to show a solar cycle dependence over the last five cycles. The average track crossing the region at latitudes north of 50°N is some 2° of latitude further south at sunspot maximum than at sunspot minimum. The effect arises from an increase at sunspot maximum in the proportion of depressions that are diverted from a main track across the Norwegian Sea into a subsidiary track further south crossing the North Sea. For the much smaller number of depressions which follow a more southerly route (south of 50°N) towards the Mediterranean there is a suggestion of a latitude change with the solar cycle in the opposite sense to that found for the northerly depressions.This phenomenon has also been examined in relation to the possible steering of cyclone tracks by the mean tropospheric flow at the 500 mb level. The results are discussed in relation to other published work, and some suggestions are made linking the phenomenon with other aspects of solar activity influences on the general circulation of the atmosphere.
Article
Based on monthly average air temperature of Shapingba in Chongqing over the period from 1958 to 2007, the cycles on various scales of temperature fluctuation patterns are analyzed by Empirical Mode Decomposition(EMD). After applying EMD to the data, a series of cycle modes and a trend are obtained respectively, including short periodic oscillations and medium periodic oscillations. Their corresponding average periods are calculated by the Fast Fourier Transform Algorithm (FFT). Those components of periods like 1 year, 1.5 years and 2.78 years belong to the former; while the periods of 7.14 years and 10 years belong to the latter. Besides, the monthly average air temperature in Shapingba of Chongqing took on descending trend before 1984, while ascended since then, which coincide with the previously obtained consequence. All the above results indicate the air temperature fluctuate on various time scales and enlighten us to find its possible reason.
Article
Many and varied claims have been made over many years for a relationship between weather or climate and solar variations, notably sunspot cycles. Those relating primarily to the single and double sunspot cycles (of about 11- and 22-year quasi-periodicities) are critically reviewed in the light of what is known about solar variations, the observed variability of weather and climate, and possible physical connections between the two. Various pitfalls in the application or lack of application of statistics to the problem are discussed and illustrated from the literature. Following a survey of the literature it is concluded that despite the great number of recent papers on the subject, little convincing evidence has yet been produced for real correlations between sunspot cycles and the weather/climate on the 11- and 22-year time scales, although evidence for correlations with solar events on time scales of days appears to exist. The state of the literature in this particularly controversial area must raise doubts as to the prevailing standards of objectivity and critical analysis in other areas of science as well. Clearly, in the case of sun-weather relationships, further research requires much higher standards of objectivity, with the rigorous and critical application of statistics, and step by step investigation of hypothetical mechanisms. This criticism is not addressed to the recent studies of apparently significant correlations between certain meteorological indices and the passage of interplanetary magnetic sector boundaries; however, the relevance of such correlations to time scales of climatic interest has yet to be demonstrated.
Article
The tropical ocean-atmosphere system is an essential component of the Earth's climatic system. High quality instrumental records are generally limited to the past decades and to isolated sites. Fortunately, chemical tracers and coral growth can be used for high resolution studies of environmental Parameters such as sea surface temperature, salinity, rainfall, nutriment and river input. Corals also act as useful monitors of man's impact on reef environments. Interest in the use of actual and fossil corals for environmental studies has rapidly increased during the past 20 years with technical progress. Realisation of the full potential of corals as sources of proxy climate information requires ongoing development of the necessary understanding of how information is stored in coral skeletons and how it can be distorted by physiological growth processes. This paper briefly reviews the possibilities offered by reefs to investigate environmental variabilities at different scales (from season to century).
Article
We show that the aliasing criticism is inadequate because the real quasi-biennial oscillation departs from an ideal sine wave in a way that reduces aliasing effects to insignificant levels. The nonuniqueness of identification of the 11-year solar cycle as the period of the arctic forcing for the Arctic winter stratospheric temperatures is a problem only for the short 33-year record of polar temperatures; in much longer time series of unstratified climate data the periods of 11 and 22 years are prominent. Highly unique signatures of solar wind forcing of tropospheric dynamics exist on the day-to-day time scale via two independent inputs to atmospheric electricity. These are (1) through changes in tropospheric ion production as a result of solar wind modulation of galactic cosmic rays and (2) through changes in the potential difference between the polar ionospheres and the surface, forced by the solar wind By component. The product of the cosmic ray flux and the ionospheric potential determines the vertical air-earth electrical current. -from Authors
Article
The Earth's atmosphere evolution through geological times has induced significant changes in its composition. The properties of today's atmosphere, due in particular to the presence of oxygen, show strong evidence of the Sun–Earth relationship. The influence of solar activity will be presented, concerning the neutral and ionised atmosphere including the magnetosphere, the thermosphere down to the troposphere, and climate as well as the various consequences on our environment (space weather).
Article
By how much does changing radiation from the sun influence the earth's climate, presently and in the recent past, compared with other natural and anthropogenic processes? Current knowledge of the amplitudes and timescales of solar radiative output variability needed to address this question is described from contemporary solar monitoring and historical reconstructions. The 17-yr observational database of space-based solar monitoring exhibits an 11-yr irradiance cycle with amplitude of about 0.1%. Larger amplitude solar total radiative output changes-of 0.24% relative to present levels-are estimated for the seventeenth-century Maunder Minimum by parameterizing the variability mechanisms identified for the 11-yr cycle, using proxies of solar and stellar variability. The 11- and 22-yr periods evident in solar activity proxies appear in many climate and paleoclimate records, and some solar and climate time series correlate strongly over multidecadal and centennial timescales. These statistical relationships suggest a response of the climate system to the changing sun. The correlation of reconstructed solar irradiance and Northern Hemisphere (NH) surface temperature anomalies is 0.86 in the pre-industrial period from 1610 to 1800, implying a predominant solar influence. Extending this correlation to the present suggests that solar forcing may have contributed about half of the observed 0.55°C surface warming since 1900 and one-third of the warming since 1970. Climate model simulations using irradiance reconstructions provide a tool with which to identify potential physical mechanism for these implied connections. An equilibrium simulation by the Goddard Institute for Space Studies GCM predicts an NH surface temperature change of 0.51°C for a 0.25% solar irradiance reduction, in general agreement with the preindustrial parameterization. But attributing a significant fraction of recent climate warming to solar forcing presents serious ambiguities about the impact of increasing greenhouse gas concentrations whose radiative forcing has been significantly larger than solar forcing over this time period. Present inability to adequately specify climate forcing by changing solar radiation has implications for policy making regarding anthropogenic global change, which must be detected against natural climate variability.
Article
Discusses the major environmental hazards affecting island ecosystems, with varying magnitudes and on differing spatial and temporal scales. Vulcanicity and earthquakes are spatially concentrated at present, but can be devastating, especially in continental-marginal areas. Island area and elevation are subject to changes in sea level, notably on Pleistocene time scales but continuing to the present. Tsunamis are episodic sea-level disturbances which may have catastrophic effects. Of climate factors variability in rainfall has greatest ecological consequences: the authors examine temporal variation in annual rainfall on islands, rainfall seasonality and its variability, the magnitude and frequency of daily rainfalls, and the magnitude and frequency of droughts. Some perturbations are linked to El Nino, and many show regional and temporal coherence. The most extreme climatic disturbances experienced on islands are hurricanes, which vary in frequency both spatially and temporally. This inherent environmental variability and associated extreme conditions has major consequences for the establishment and survival of plants and animals on islands, especially through the control of vegetation growth by rainfall. -from Authors
Article
Aspects of solar variability and the variation of the geomagnetic field are examined in the context of solar-terrestrial relations. Known and suggested periods, characteristic times, and events in solar-terrestrial relations are presented in a table. Changes in the solar wind and in the geomagnetic field cause variations in the magnetosphere. A description of magnetospheric variability is presented, taking into account dipole scaling relations, nondipolar models, and interior neutral points. Possible applications of the study of long-term solar terrestrial relations are also discussed, giving attention to the helium budget, long-term solar terrestrial relations and weather, trapped particle radiation, implications for archeology, and solar proton events, ozone, geomagnetic reversals, and life.
Article
The authors tried to find a connection between the solar activity and the outbreaks and daily light-trap catches of Scotia segetum Schiff. It has been established by means of autocorrelation and cross-correlation functions that, the outbreaks are connected with the solar cycle. A moderate increase of solar radio flux measured at 2800 MHz in preceeding day coincided with an increase however, a slight decrease or marked increase of the radio flux with a decrease in the light-trap catches. On nights following the solar H-alpha flares of importance (class) 2 and 3, the yield of light-trap catches also decreased. The results of this paper may find an application in the plant-protecting forecasting. Einfluß der Sonnenaktivität auf die Gradation und Lichtfallenfänge von Scotia segetum Schiff. (Lep., Noctuidae) Die Autoren untersuchten, ob ein Zusammenhang zwischen der Sonnentätigkeit und der Gradation bzw. den täglichen Ergebnissen der Lichtfallenfänge von Scotia segetum besteht. Es wurde mit Hilfe von Auto- und Kreuzkorrelationsrechnungen gefunden, daß die Gradationen mit dem Sonnenzyklus im Zusammenhang stehen. Eine mäßige Zunahme des Sonnenfluxus, gemessen im Frequenzbereich von 2800 MHz am vorangehenden Tag, erhöhte -, eine stärkere Zu- oder Abnahme dagegen verminderte die Lichtfallenfänge. Die H-alfa chromosphärischen Eruptionen (Flare) der Intensitätsklasse 2 und 3 verminderten die Lichtfallenfänge am folgenden Tag. Die Ergebnisse dieser Arbeit können für die Pflanzenschutzprognose Verwendung finden.
Article
Cohen and Sweeter (1975) found the 20 to 22-year Hale (double sunspot) cycle signal in the maximum entropy spectra of sunspot and Atlantic tropical cyclone data. Currie (1996) corroborated and extended their analysis, but he argued that this signal is the 18.6-year luni-solar tidal constituent. Currie maintains that Cohen and Sweeter mistakenly conjectured that this long term periodicity was induced by the 20 to 22-year Hale cycle signal. However, no further investigation of periodicity in the extracted wave forms corresponding to the 18.6-year luni-solar signal was conducted. In this study, we follow Currie's signal processing procedures to extract the wave forms corresponding to the 18.6-year luni-solar signal. In order to investigate the periodicity in the extracted wave forms, multi-taper method (MTM) is used for harmonic analysis. Band pass filters are then designed to extract the wave forms corresponding to the individual components identified in the MTM harmonic analysis. The investigation results of the monthly precipitation and Palmer's drought severity index (PDSI) data in three of the midwestern states – Illinois, Indiana and Ohio – show that two periodic components, the 20 to 22-year Hale cycle signal and the other component with periods between 16.9 and 13.5 years, are identified. The bistability phenomenon, which Currie found in these wave forms, is more likely to result from the superposition of these two periodic components, rather than from a nonlinear mechanism. Besides, a periodic component with an approximate period of 33 years is detected.
Article
Annual landings of shrimp (Crangon crangon) in the Lancashire and Western Sea Fisheries District (UK) have previously been predicted 1 year in advance on the basis of rainfall and air temperature records of the previous year. For the port of Lytham, abundance of shrimp has been found to be correlated with mean sunspot number. Since sunspot number can be predicted fairly accurately, this correlation has given the prediction of landings a greater accuracy than was formerly possible. Sunspot numbers can be predicted for a considerable period of time in advance, and therefore abundance of C. crangon at Lytham can be estimated for several years.
Article
The EMD (empirical mode decomposition) method has exhibited superiority and potential in applications related to the processing of nonlinear and unsteady time sequences. For the research of periodicity of solar activity by means of the EMD method, the monthly mean values of sunspot numbers in 110 years (1894-2003) and 55 years (1949-2003) are analyzed, resulting in a series of modes and one trend term. For all of them the periodic components of 1.3-1.4 years, QBO (quasi-biannual oscillation) components of 25-30 months, the 11-year solar cycle component as well as the 22-year Hale cycle component are possibly included. The amplitude of the component of the 11-year cycle is the largest, and the characteristics of variation of this component are highly correlated with the original data of sunspot numbers. Being different from traditional methods, the EMD technique can provide the characteristics of isolated features on various time scales.
Article
Full-text available
A possible relationship between sunspot number and total annual precipitation from the Izana Observatory has been found. The annual precipitation period ranges from 1916 to 1998, thus including nearly eight 11-year solar cycles. When points of total precipitation for a given year at Izana are plotted on the ordinate axis versus the yearly sunspot number on the abcisa axis three years back from the precipitation one, nearly all of them lie in the lower left hand corner of the diagram. This seems to indicate a relationship between the above mentioned variables. If this relationship is confirmed it would permit the prediction of a maximum annual precipitation at Izana three years in advance.
Article
By utilizing the maximum entropy method of Burg, evidence has been found for the solar cycle signal in power spectrums of late nineteenth and twentieth century surface air temperature data from the North American continent. Nominal amplitude (uncertain by a factor of 2) is 0.1°C, and the period is 10.6 ± 0.3 years.
Article
The estimated spectral maximum was found to shift in relation to the true maximum. The frequency shifts depend upon the initial phase and the length of the sinusoid. The influence of the number of terms in the prediction error filter, the number of the data samples, and the noise intensity are also considered. Conventional methods of power spectral estimation have certain drawbacks when it comes to analyzing short time seriesß For estimates based on the periodogram, Toman [1965] shows that the spectral maximum of a truncated sinusoid occurs at zero frequency when the length is less than 0.58 times the period of the sinusoid. In addition to the spectral shift problem there is a loss of' resolution whenever the data lengths are comparable to the period [Ulrych, 1972]. In the case of the autocorrelation method, which estimates the power spectrum by Fourier-transforming the autocorrelation, it sometimes indicates negative power at some frequencies if the data samples are inadequate. Burg [1967, 1968] suggested a radically different approach for the estimation of power spectrum. This technique is especially valuable for the short data samples frequently encountered in geophysical problems. Basically, the new approach generates a unique filter based upon the information contained within the available data samples. The filter is applied to the time series and serves to whiten the input data samples. Since the output spectrum is a constant, the spectrum of the input data is proportional to the reciprocal of the power response of the filter. Some discussions about this new technique can be found in Lacoss [1971] and Ulrych [1972]. The purpose of the present work is to present the results of some experiments with Burg's new approach applied to short sinusolds. A simpler version of the present work has been reported by Ulrych [1972]. However, the present results are different from his in several respects. In view of the potential value of Burg's new technique for analysis of geophysical data it seems warranted to present a detailed discussion of some of its advantages and limitations. THEORETICAL BACKGROUND
Article
In his presidential address before the Royal Meteorological Society, Sutcliffe [1956] stated: ‘In accounts of the general circulation it (the tropical cyclone) is usually ignored or added as an embroidery of no basic importance except for areas subject to its violence’ He also called attention to the importance of tropical storms as climatic elements. As part of the same paper he quotes data from J. K. Bannon on the precipitable water contents of the atmosphere in January and July over the two hemispheres. For the northern hemisphere the average precipitable water in midwinter and midsummer amounts to 20 mm and 35 mm, respectively. For the southern hemisphere the spread is much smaller. The midwinter value is the same as in the north, but the summer value is only 5 mm larger.
Article
The frequency shifts observed in the power spectra of truncated sinusoids, when the sinusoids are computed by using the periodogram, are obviated when the power spectra are determined by means of a maximum entropy algorithm.
Article
THE existence of a long period undulation (~179 yr) in the solar cycle (Fig. 1, based on data from Waldmeier1,2 is suggested by the planetary theory of sunspots. Jose3, for example, postulated an association between the 178.8-yr periodicity in orbital positions of the planets and the phase of the solar cycle. Wood4 used the presumed existence of a cycle of 170–180 yr in solar activity to predict the peak dates of future sunspot cycles. Our work indicates that although a 179-yr periodicity does exist in the sunspot cycle, it is not caused by a primary long term excitation function but is, instead, a beat phenomenon. This can be seen by computing the spectrum for the data shown in Fig. 1.
North Atlantic Tropical Cyclones, 1973, from NOAA Climatological Data, National Summary, 24 (NOAA
  • P J Herbert
  • PJ Herbert