Zmienność inwersji temperatury powietrza nad Krakowem w świetle warunków cyrkulacyjnych

Variability of air temperature inversions over Cracow in relation to the atmospheric circulationTemperature inversion is a phenomenon in which air temperature increases with altitude. The studies on air temperature inversions in Cracow were based on various data and methods e.g. data from standard and automatic meteorological stations, radiosonde observations, lidar and sodar measurements. They showed the annual and diurnal variability of temperature inversions, but most of them did not investigate the multi-annual trends in the occurrence of temperature inversions. Due to the relationship between meteorological conditions and air quality, it is important to study the multi-annual, annual and diurnal variability of air temperature inversions. The main aim of this article is to determine the multi-annual variability of air temperature inversions in Cracow and its relation to synoptic situation. Moreover, the annual and diurnal variability of temperature inversions is shown. The study is based on data derived from NCEP - NCAR reanalysis and the classification of synoptic situation types by T. Niedźwiedź. In this paper two parameters of inversions are presented – frequency and intensity. The study confirmed that the frequency and intensity of inversions have annual and diurnal variation. Multi-annual changes in the numbers of days with temperature inversion were also observed – a statistically significant increase in the 1000 – 925 hPa layer as well as in the intensity of temperature inversions – a statistically significant increase in the 1000 – 925 hPa, 1000 – 850 hPa and 925 – 850 hPa layers. It was proved that a very strong relationship exists between the days with temperature inversion and the anticyclonic situation, especially with the air-flow from south, south-west and south-east.