全球变化知识资源中心

In recent years, several unusual (or at least very rare) weather events occurred in the Carpathian Basin, e.g., the severe snow in March 2013. We are assuming that this anomaly may be a part of the climate change-related macro-scale circulation changes, especially the changes in the characteristics of polar jetstream. For evaluating this hypothesis, we performed a detailed statistical analysis of the high level wind fields of the region for 22 vertical layers above the 500 hPa pressure level, including the detailed analysis of average wind speed and wind directions, trend analysis of daily wind speed values, and extreme wind speed values. The results show negative trends in the mean wind speed at the higher tropospheric levels, and positive trends at the very high stratospheric levels in the Carpathian Basin. Furthermore, statistically significant trends mostly occurred in westerly winds, which is the most frequent wind direction.