Spatiotemporal variability and trends in global solar radiation over Poland based on satellite‐derived data (1986–2015)

Abstract

Incoming solar radiation is the most important factor shaping climate system on Earth and the main element of the surface heat balance. The main aim of this study was to investigate the changes in the amount of global solar radiation reaching the Earth's surface in Poland during the 30-year period 1986-2015. Trends in changes and fluctuations in the size of global solar radiation over Poland were determined. The solar radiation was described based on satellite products originating from the Surface Incoming Shortwave Radiation product from the Surface Solar Radiation Data Set-Heliosat, Edition 2 (SARAH-2). The average annual sum of global solar radiation over Poland amounted to 3,902 MJÁm −2. The average annual radiation sums were the smallest in northern Poland and mountain basins, while they were the largest in southern Poland. The average annual radiation sum over Poland increased by 7.16 MJÁm −2 Áyear −1 on average. The areas with the largest increase in the amount of solar radiation had the smallest average radiation sums during the multi-year period (Pomerania, Northern Poland), and those where the increase in radiation was moderate had the highest average radiation sums (Central and Southern Poland). This shows that the spatial differentiation of the amount of solar radiation over Poland was gradually decreasing during this period. A several-year cycle (of 12-13 years) of annual fluctuations in global solar radiation sums was observed using wavelet analysis. The cycle was visible between the early 1990s and 2005. It resulted from the medium-term cyclical component (an 11.3-year cycle which was the strongest until 2010) that occurred in summer. In the long term, the occurrence of cycles in the time series of solar radiation may result from cyclical or quasi-cyclical changes in aerosol concentration, but this requires a separate study and further in-depth research based on much longer data series.

Influence of air pressure patterns over Europe on solar radiation variability over Poland (1986–2015)

“…Average annual sums of GSR (MJ·m −2 ·year −1 ) over Poland in 1986–2015 (a), the slopes of the linear trend in GSR (MJ·m −2 ·year −1 ) over Poland during the multi‐year period 1986–2015 (b) and the statistical significance of this trend at a significance level of α = 0.05 (c) (statistically significant trend is highlighted) (source: Kulesza, 2020)…”

“…Spatiotemporal variability and trends in GSR over Poland in the period 1986-2015 are described in detail in our previous paper (Kulesza, 2020), a short recap is also presented here. In 1986-2015, the average annual sum of GSR over Poland amounted to 3,902 MJ•m −2 , and its spatial distribution reflected the arrangement of the main features of the topography: the average annual GSR sums were the smallest in lake districts and mountain basins, while they were the largest in southern Poland (Figure 3a).…”

“…I G U R E 3 Average annual sums of GSR (MJ•m −2 •year −1 ) overPoland in 1986Poland in -2015, the slopes of the linear trend in GSR (MJ•m −2 •year −1 ) over Poland during the multi-year period 1986-2015 (b) and the statistical significance of this trend at a significance level of α = 0.05 (c) (statistically significant trend is highlighted) (source:Kulesza, 2020) F I G U R E 4 The correlation coefficient between the average annual sum of GSR over Poland and SLP over Europe and the North Atlantic during the period 1986-2015. The areas where significant correlations were found are hatched, the area with the strongest positive correlation is marked with a plus, and the area with the strongest negative correlation is marked with a minusT A B L E 3The correlation coefficient between monthly mean NAO index values and GSR monthly anomalies over Poland during the period Statistically significant values at the level of significance α = 0.05 are in bold type.…”

Wavelet-Gaussian Process Regression Model for Regression Daily Solar Radiation in Ghardaia, Algeria

“…Because of the importance of choosing the type of wavelets to decompose the variable input into details and approximation components in the precision of the models [29,30], Table 2 presented the results of the application of eight mother wavelet, the highest precision concerns coif1 (Coiflet) (RMSE = 1.81 MJ/ m 2 Day).…”

Solar Climate Features Taking into Account the Morphometric Conditions of the Area and the Possibility of Using Them in Heliotherapy on the Example of the Cieplice and Kołobrzeg Health Resorts (Poland)

“…The research conducted in the field of remote sensing techniques has mainly included biometeorological and urban climate models [45][46][47], simple modeling of bioclimatic conditions using GIS software [48], estimation of radiation fluxes in complex-city structures [49,50] also taking into account the issues of urban heat islands (UHI) [51][52][53]. Long-term trends of solar radiation used satellite datasets were investigated for the Iberian Peninsula by Montero-Martin et al [54], for the Baltic region by Lindfors et al [55], and for the territory of Poland by Kulesza [56]. However, none of them analyzed in detail the relationship between the solar features of the climate and the morphometric conditions of the area with the possibility of using them in heliotherapy, which indicates the originality of the presented results.…”