Air saturation deficit as an indicator of variability of air humidity in Kraków

Bibliogr. s. 287, streszcz. w jęz. pol.

The aim of this paper is to present the variability of air humidity conditions in Kraków by analysing long-term course and frequency of particular values of the air saturation deficit. Air temperature values from the period of 1901-2000 were used to calculate saturation deficit values. The basic statistical characteristic, the analysis of variability tendencies in the examined period and the probability of characteristic days (d//>10.0 hPa, dav>12.5 hPa), and extreme values occurrence in particular synoptic situations were worked out. The analysis showed that the air in the city is getting dryer. Statistically significant increasing tendency of summer months means (up to 3.0 hPa/100 years in August) and annual mean (1.4 hPa/100 years) values of the parameter, as well as growing occurrence of the frequency of days with characteristic air saturation deficit values, particularly after 1970, are the evidence. Statistically significant correlation with atmospheric circulation indices variability is noticeable mainly in winter, when the variability of air humidity is not clearly visible. It proves that local and anthropogenic factors have an essential impact on forming the humidity conditions in Kraków.