Abstract (eng)
Quantification of the global atmospheric and oceanic energy budgets is one major branch of climate research. Especially the variability of the budgets on various timescales is of great
interest for fundamental research but also for climate change research. For example, validation of climate models requires sound observational estimates as reference. The two main aims of this study are to (i) give a new estimate of poleward atmospheric energy transports and (ii) to describe the variability of atmospheric and oceanic energy budgets in association with El Niño-Southern Oscillation (ENSO).
The first part of this thesis is concerned with the atmospheric energy budget as evaluated from the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis Interim (ERA-Interim). Based on this state-of-the-art dataset, a new estimate of climatological mean poleward atmospheric energy transports is given. While results for peak transports in the Northern Hemisphere agree well with earlier estimates, results for the Southern Hemisphere suggest stronger mean atmospheric poleward transports than earlier studies. Moreover, several aspects regarding physical consistency and temporal homogeneity of the ERA-Interim dataset
are discussed.
The second part of this thesis is concerned with the variability of atmospheric and oceanic energy budgets in the tropical belt. Novel results show quantitatively consistent energy exchanges between the three tropical ocean basins via the atmosphere in association with ENSO.
This thesis contributes to our understanding of large-scale climate dynamics and also provides results which can serve as a quantitative benchmark for validation of coupled climate models.