COMPARISON OF SATELLITE AND TERRESTRIAL DATA OF OBSERVATIONS OF SUNSHINE DURATION ON THE EXAMPLE OF THE TERRITORY OF UKRAINE

Abstract

In this article, a comparison of satellite and terrestrial data on the sunshine duration is determined on the example of the territory of Ukraine for the period of the calendar summer of 2011-2019. In particular, it was established that the value of the correlation coefficient of satellite and terrestrial ancient of sunshine duration is within 0.50 – 0.80, which corresponds to a moderate and significant correlation, and therefore a sufficiently large dependence between these types of obtaining meteorological and actinometric information of the studied parameter. Attention is also focused on the possibilities of improving the accuracy of ground data using universal multi-purpose solar radiation sensors, for example BF5 type sensors; and high accuracy of satellite data is confirmed. The average total error of the sunshine duration was determined based on satellite data and data from terrestrial weather stations. The obtained results indicate that ground weather stations have several times lower accuracy of measurements, in contrast to satellite data. After all, the average maximum total error of the sunshine duration of terrestrial data is four times higher than the average maximum total error of satellite data of the studied quantity. This, in turn, allows us to use satellite data for a qualitative assessment of the sunshine duration on the territory of Ukraine and allows us to assert that, in addition to ground data, it is possible to use satellite data of the sunshine duration as a studied quantity, as well as satellite data of any quantity in general. In addition, the influence of weather and climate anomalies on the obtained comparison results was investigated. As a result of the research, it was noted that mostly the months with the best correlation correspond to a more homogeneous anomaly of air temperature and precipitation, and the months with the minimum correlation are merked by significant heterogeneity in the space of anomalies of the fields of these meteorological quantities. On a territorial scale, when analyzing data on the sunshine duration, it is necessary to detail meteorological values that depend on the studied parameter by region or individual areas.