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ABSTRACT For a better understanding of multidecadal climate change, as well as for the production of solar power, there is a growing need for knowledge of the trends in incident sunlight at the Earth's surface, but a lack of a long-term sunlight time series dictates that a proxy measure is needed. In this study, variations of sunshine duration and diurnal temperature range ( DTR) are used as proxies for surface solar radiation. Annual and seasonal composites of both variables from 29 stations are analyzed from 1961 through 2009 across the different types of climates of Iran. The annual sunshine duration mean time series shows a decrease from the early 1960s to the late 1970s, in line with the widespread dimming of surface solar radiation observed during this period. By the early 1980s, there is an increase in sunshine through the end of the 20th century, aligning with a well-known and well-documented brightening period. In addition, a renewed dimming is observed during the 2000s, with a sharp drop in 2009. A linear trend estimated over the 1961-2009 period was not found to be statistically significant. However, the annual DTR time series shows a widespread and statistically significant decrease since the 1960s, although the series ends without relevant variations after the 1990s. An agreement in the interannual variability of sunshine and DTR is observed except for the summer season. On decadal time scales, only the spring DTR series shows a partial agreement with sunshine series. Nevertheless, the recent leveling off in the DTR series supports a transition in the radiative regime. [ABSTRACT FROM AUTHOR]

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The present paper studies the variability and trends of Tropical Nights (>20 °C) (TNs) on the Iberian Peninsula (IP) over the 1961-2007 period during the extended summer (defined as June, July, August, and September, JJAS). The analyses were performed with the mean series calculated for the whole IP and for different subregions. We conducted a regionalisation by means of a S-Mode Principal Component Analysis (PCA), which identified three subregions where the variability of TNs behaves similarly: the Mediterranean (M) region, the centre-north of the Peninsula (CN) region, and the Atlantic (A) region. Throughout the entire period, the mean summer TN series for the whole IP shows a significant increase; there are, however, some regional differences, as the CN and M regions present higher rates of warming than the A region. Using Canonical Correlation Analysis (CCA) we detected the large-scale atmospheric circulation patterns controlling the interannual variability of TNs over the IP. The occurrence of TNs in the M and CN subregions is highly dependent on anticyclonic conditions over Western Europe in the mid-troposphere level. The increase in the positive phase of this canonical mode during the last three decades might explain part of the positive trend of the TNs detected in summer on the IP. Copyright © 2011 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP) with an average elevation of over 4,000 m asl is the highest and most extensive highland in the world. We used monthly mean sunshine duration from the Chinese Meteorological Administration to examine the spatial and temporal variability of sunshine duration at 71 stations with elevations above 2,000 m asl in the eastern and central TP during the 1961–2005 period. The temporal evolution of the mean annual sunshine duration series shows a significant increase from 1961 to 1982 at a rate of 49.8 h/decade, followed by a decrease from 1983 to 2005 at a rate of −65.1 h/decade, with an overall significant decrease at a rate of −20.6 h/decade during the whole 1961–2005 period, which is mainly due to the summer and spring seasons. This confirms the evidence that sunshine duration in the TP ranges from brightening to dimming in accordance with sunshine duration trends in the rest of China. The surface solar radiation downwards from ERA-40 reanalysis data in the same region confirms the brightening/dimming phenomenon shown by the sunshine duration before/after the 1980s. Otherwise, additional climatic variables such as low cloud amount, total cloud amount, precipitation, relative humidity and water vapor pressure, in most cases, exhibit significant negative correlation with sunshine duration in the TP on an annual and seasonal basis before and after 1982, respectively. The trends of these variables suggest that changes in some of them might be related to the brightening and dimming detected with the use of sunshine duration measurements over the TP. We also hypothesize that the impact of anthropogenic aerosols upon the climatic variables analyzed cannot be rejected, especially in the significant increase in low cloud cover since approximately 1980. [ABSTRACT FROM AUTHOR]

Suicide is a serious public health problem around the world. Since the nineteenth century, the impact of socio-environmental factors on suicide has attracted much public attention, especially in the context of global climate change. We have performed a retrospective correlation study that analyzes the demographic pattern of suicide in Cantabria, a northern coastland region of Spain. Moreover, we have created a multivariable binomial regression model to study the relationship between suicide and environmental factors (atmospheric pollutants and meteorological variables) among January 1, 2000, and December 31, 2013 in the province. During the 14-year study period, there was a suicide annual incidence of 4.9 cases per 100,000 population in Cantabria. The incidence was highest in adults aged 70-74 years old (11.8 per 100,000 population). The most common method group of suicide was hanging, strangulation and suffocation, accounting for 49.3% of all suicide deaths. When correlating suicide and meteorological variables, a statistically significant association was found with the level of cloudiness (p = 0.007). According to our results, an increase of one eighth of sky cloud-cover correlated to a 7% increase in total deaths by suicide and the association was especially strong during spring.