Climate Feedbacks in the Antarctic from Stratospheric Balloon GPS Radio Occultation Soundings

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

New efforts to assimilate satellite borne, high-resolution infrared (IR) sounding data from IASI and AIRS satellite radiances are providing much denser information on upper air temperature and humidity. Such efforts have the potential to greatly improve the skill of numerical weather prediction (NWP) model forecast and reanalysis products for the undersampled atmosphere of the southern hemisphere. This is one of the key aims of the CONCORDIASI campaign, a USAP supported IPY project. However, significant biases remain in the IR profiles due to cloud contamination and surface emissivity uncertainties that are specific to the Antarctic environment. This study seeks to improve the quality of global and regional reanalyses using GPS radio occultation profiling techniques made from stratospheric balloon platforms encircling Antarctica in the spring polar vortex. The study is intended to reduce biases in the satellite sounding observations, and to develop the capability for assimilating the balloon GPS RO profiles directly into NWP models. Improved satellite soundings, or balloon borne GPS radio occultation profiling, will help our characterization of southern hemisphere temperature, moisture and circulation features needed for better understanding of phenomena such as ozone depletion, and the workings of the polarity of the Southern Hemisphere annular mode (SAM). Uncertainty as to the future evolution of the climate systems in the polar regions limits our ability to project global climate variability and change.