Influence of planetary waves in the troposphere on temperature extreme events at the ground

Kurzfassung

Climate change leads to various changes in temperature and temperature distribution in the troposphere, as can be seen in increasing temperature extremes in higher latitudes. As temperature in the troposphere and large-scale weather phenomena at higher altitudes influence each other, it is likely that climate change also affects large-scale temperature atmospheric waves, Planetary Waves. ERA-5 Temperature data between 1979 and 2019 is being used to identify temperatures that differ more than 2Sigma from the mean over all years and over a 10° latitude range for different altitudes. The result is a time-longitude map within the Northern Hemisphere that can be analyzed for clusters of extreme temperatures, which represent extreme temperature events. With a spectral analysis, the harmonic analysis, the amplitude and phase of the 9 largest wave numbers can be determined, and the contribution of single waves to extreme events can be investigated. Examples of the extremest between 1979 and 2019 on surface-level will be identified in the temperature data and the planetary waves governing those extreme temperature events will be identified. A broader picture will be given by discussing the general rate of individual waves overlapping with extreme events. The visibility of those events in higher altitude Planetary Waves will be discussed. This work received funding from the Bavarian State Ministry of the Environment and Consumer Protection.