On the seasonal variation of local relationships between temperature, temperature range, sunshine and cloudiness

Abstract

This paper discusses the cloud cover and its relation to atmospheric circulation over Spitsbergen during 1983Spitsbergen during -2015. It focuses on monthly and seasonal cloud covers and on the frequency of days with specific cloud cover (cloudless, clear, cloudy and completely overcast sky) and their relation to various circulation types. In the research period the cloud cover characteristics were differentiated over the island on both monthly and seasonal scales, and they strongly depended on the direction of air advection. The highest mean daily cloud cover was reported for circulation types with air advection from the south (S+SWc and S+SWa). The greatest variation in the cloud cover distribution was observed during the polar night (at Svalbard Lufthavn and Ny-Ålesund) or in the autumn (Hornsund). The long-term variability in the cloud cover significantly depends on the frequency of N+NEa type (negative correlation) and on S+SWc and W+NWc and Cc+Bc types (positive correlation), particularly in spring.

Disaggregating climatic trends by classification of circulation patterns

“…The cloudiness and sunshine changes fit the trends observed in other regional and local central European series well (Brázdil et al, 1994a;Weber, 1994). Cloudiness rises in both seasons at both stations, its increase being only significant in Prague.…”

Influence of cloudiness on sunshine duration

“…According to Brázdil et al (1994), it is very important to analyze changes in sunshine duration driven by changes in cloudiness in the era of global warming. Weber (1994) puts forth the hypothesis that increasing cloudiness is more likely to impede outgoing long-wave radiation than incoming solar radiation during the winter. This is believed to cause a net warming of the atmosphere.…”

“…Stanghellini (1981) developed a universal model designed to estimate monthly sunshine duration totals based on daytime cloudiness and was able to show that the model works and can be used in other areas, especially in countries with a more stable climate. Weber (1994) used data collected in Berlin to show that 'sunshine duration may therefore be a more accurate indicator of daytime cloudiness than cloud cover observations themselves. Moreover, sunshine duration should only be compared to daytime cloudiness.'…”

Trends of minimum and maximum temperature in Poland

“…According to TAR (2001), the night-time air temperature over land increased by about 0.2°C decade -1 between 1950 and 1993 and the daytime air temperature increased by only 0.1°C decade -1 . Since the analysis of Karl et al (1993) did not concern Central Europe, only a few papers seem to fill this gap (Böhm & Auer 1994, Brázdil et al 1994, Lapin & Fa$ko 1994, Miȩtus & Owczarek 1994, Niedźwiedź & Ustrnul 1994, Weber 1994. Brázdil et al (1996), summing up these papers, stated that the tendencies in Central and South-Eastern Europe did not follow that suggested by Karl et al (1993).…”