| Popis: |
This diploma thesis is concerned with long-term changes in precipitation phase in Europe since 1961 to 2004. Precipitation phase is described by the ratio of snow to total precipitation (S/P) between November and April. The first part is engaged in changes in precipitation phase in the Czech Republic. The S/P ratio in the Czech Republic is decreasing (not significantly) by 0,19%/year. In the second part are used temperature and precipitation data from 10 Czech meteorological stations to determine the threshold temperature. This threshold temperature is 1,1řC (daily average temperature) and is used as indicator of precipitation phase. If there is a daily temperature higher than the threshold temperature, daily precipitation sum is signed as rain and vica versa. This threshold temperature is afterwards applied to temperature and precipitation data at 148 European stations and there is also found out relation between S/P ratios and indexes of 4 the most important teleconnections in Europe. It is shown that long-term trend of S/P ratio is negative and significant, however regionally different. There is a southwest - northeast gradient and the biggest decline is recorded in the central Europe and adjacent areas of Scandinavian Peninsula, but the decline of S/P ratio is slowing toward northwest Russia... |
