The Surface Mass Balance in a Regional Climate Modelof Antarctica

Understanding the Earth's climate system andparticularly climate variability presents one ofthe most difficult and urgent challenges in science.The Antarctic plays a crucial role in the globalclimate system, since it is the principal region ofradiative energy deficit and atmospheric cooling. Theregional climate model HIRHAM has been used forinvestigating the climate of Antarctica. Incomparison with the observations, the evaluationshows that the simulations with the HIRHAM modelcapture both the large and regional scale circulationfeatures with generally small bias in the modeledvariables. The decadal scale processes were studiedbased on trend calculations. To better understandthe horizontal structure of mean sea level pressure,temperature and netmass balance trends the influence of the AntarcticOscillation (AAO) on the Antarctic climate wasinvestigated. For detailed investigation of globalteleconnection, two positive and one negative periodsof AAO phase were chosen. The differences in MSLP and2m temperature between positive and negative AAOyears during the winter months partly explain thesurface cooling during the last decades.

Autorentext

From 2000 Annette Mortensen worked as the Refugee Health Coordinator in Auckland, New Zealand. In 2007, Annette was presented with the Supreme Harmony award for her contribution to Muslim relations in New Zealand. Annette continues to work to improve health outcomes for refugee, Asian and migrant communities in the Auckland region.

Klappentext
Understanding the Earth's climate system and particularly climate variability presents one of the most difficult and urgent challenges in science. The Antarctic plays a crucial role in the global climate system, since it is the principal region of radiative energy deficit and atmospheric cooling. The regional climate model HIRHAM has been used for investigating the climate of Antarctica. In comparison with the observations, the evaluation shows that the simulations with the HIRHAM model capture both the large and regional scale circulation features with generally small bias in the modeled variables. The decadal scale processes were studied based on trend calculations. To better understand the horizontal structure of mean sea level pressure, temperature and net mass balance trends the influence of the Antarctic Oscillation (AAO) on the Antarctic climate was investigated. For detailed investigation of global teleconnection, two positive and one negative periods of AAO phase were chosen. The differences in MSLP and 2m temperature between positive and negative AAO years during the winter months partly explain the surface cooling during the last decades.