ausblenden:
Schlagwörter:
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Zusammenfassung:
Climate change leads to latitudinal differing temperature trends in the troposphere. A changing meridional temperature gradient influences large-scale atmospheric waves, the planetary waves (PW), which are linked to large weather patterns. Therefore, PW can impact weather extremes. The questions “to what extent can temperature extremes be attributed to PW” and “what are the leading PW?” will be addressed in this presentation. In order to identify temperature extremes (temperatures that differ more than from the mean of a specific day over all years), ERA5 data of the northern hemisphere (surface level) between 1979 and 2019 is used. The result of comparing every daily temperature value with the mean for the specific date of the year is a time-longitude matrix that can be analyzed for clusters of extreme temperatures. Those clusters represent extreme events. With a spectral analysis, the harmonic analysis, amplitude and phase of the nine largest PW numbers can be determined. This is done based on ERA5 data from 1979 until 2019 within the troposphere. Examples of extreme temperature extreme events between 1979 and 2019 on surface level will be presented and the PW on surface level governing those extreme temperature events will be addressed. It will be discussed, to which extent the extremes in the PW at surface level are visible in PW at higher altitudes.
