Workshop: Stratospheric predictability and impact on the troposphere

The trend analysis needs homogenous datasets without any artificial breakpoints. The aim of this study is a detection of breakpoints in the temperature time series from the MERRA -2 and ERA 5 reanalyses with the help of the Pettit homogeneity test for all pressure layers above 500 hPa in December, January and February. We are looking for grid points where these breakpoints occur and also for years when they occur (geographical and time distribution. It is expected the results will be better for the Northern Hemisphere due to the denser data. We are interested in the spatial and vertical distribution of breakpoints as well. These results give us the knowledge about the suitability of both reanalyses temperature data for trend analysis in the future.