Janusz Olejnik

Abstract

Data from 18 meteorological stations in the southern part of Germany were analysed. Long-term average data (1958-1987) were compared with altitude data for meteo-rological stations in the Main River catchment, which varied from 150 to 920 m above sea level. Linear regression analysis against altitude was carried out for each month for six meteorological parameters: air temperature, precipitation, vapour pressure, saturation vapour pressure deficit, wind speed and relative humidity. The regression shows a very significant correlation for the analysed meteorological parameters. The annual variation to the vertical gradients for these parameters is also shown. To estimate gradient variation a Fourier expan-sion of the annual cycle is applied (given by monthly values of the gradients) and terms up to the first harmonic retained. Using the proposed functions for vertical gradient estimation, the areal distributions of temperature are calculated and average values for those parameters within the Main River catchment shown at monthly and yearly resolution. The areal distribu-tion to mean annual temperature was determined and presented as a grid map.

Keywords: Fourier expansion, vertical gradient, annual variation

Janusz Olejnik, Agrometeorology Department of The Agricultural University in Poznan, ul. Witosa 45, 60-647 Poznan, Poland
Jacek Leśny, Agrometeorology Department of The Agricultural University in Poznan, ul. Witosa 45, 60-647 Poznan, Poland
Frank Eulenstein, Zentrum fur Agrarlandschafts- und Landnutzungsforschung, Eberswalder Str. 84, 15374 Muncheberg, Germany