This is a joint project with the University of Bremen

Main research topics

The main aim of this project is to study the recent distribution of water vapour in the Antarctic troposphere, of precipitation and accumulation at the earth surface and to determine the mass balance of the Antarctic ice sheet on the basis of high resolution model simulations with a regional atmospheric model and radiosonde and satellite observations. Information from passive microwave sensors on satellites will be used to validate simulated hydro-meteorological parameters like total water vapour and temperature profiles over the sparse data region of the Antarctic continent.

To simulate the water vapour distribution accurately a very good simulation of synoptic-scale cyclones is required. The hydrological cycle on a regional scale is poorly represented with present-day coarse resolution GCMs as well as in the re-analysis products. The general objective of this project was to implement and validate the regional climate model HIRHAM with a 50 km horizontal resolution for the Antarctic area.

The whole project combines the following 3 work packages.

1. Regional model simulations

A strong focus is on the regional coupling processes between the driving large-scale circulation patterns, the meso-scale cyclones and the atmospheric water cycle. An atmospheric model is a very useful tool for achieving these objectives since precipitation and sublimation are determined by atmospheric processes. 40 year long simulations with the improved and validated model are carried out to understand the causes of ongoing changes in the Antarctic area.

2. Remote sensing with satellites

Development of retrieval algorithm for the computation of water vapour and temperature profiles over Antarctica and Arctic on the basis of passive micro wave sensors on satellites.

3. Validation of total water vapour

A further focus covers the simulation of the atmospheric water vapour distribution and the accumulation distribution over Antarctica in the simulations and here validation by the use of satellite derived water vapour distributions in both polar regions.An example of the comparison of simulated and observed total water vapour for selected days: