Zbigniew Sabatowski

Atmospheric dryness in Karkonosze Mountains

In the paper the occurrence of phenomenon of atmospheric dryness in Karkonosze Mountains in 1965-2000 is presented. This study used data on daily sums of precipitation from Meteorological Observatory of Meteorology and Climatology Department of Wroc³aw University in Karkonosze on Szrenica Mt. (1362 m asl). The data was analysed in three ways. First method based on water deficit in environment from long-term mean sums. Next, on the series of days with no precipitation observed (by A. Schmuck), while the third - on indicators of humidifying and dryness of atmosphere by S. Bac. The criteria allowed to discriminate days and periods highly above or beyond of standards. Results cannot described categorically the intensity of the phenomenon investigated. Still, it proclaims that the phenomenon occurs on every kind of terrain, even in mountains, but its impact is not so strong.

Time differentiation of precipitation during year and during many years period is similar in Karkonosze and in other parts of Odra River basin. Hence, it can be said that droughts in Karkonosze Mountains are rather typical, although irregularly occurred phenomenon. moreover, they are connected with typical atmospheric circulation over south-western part of Poland.

Due to high altitude over mean sea level this phenomenon is not so intense as elsewhere. The periods with no precipitation are rare, and the dryness last shorter.  Although the water balance showed no negative value during the year it is hard to tell what negative consequences may occur due to high deviation of the water balance.