GPS radio occultation technique for measurement of the atmosphere above tropical cyclones

Water vapour transport to the upper troposphere (UT) and lower stratosphere (LS) by deep convective storms affects the radiation balance of the atmosphere and has been proposed as an important component of climate change. The aim of the work presented here is to understand if the GPS Radio Occultation (RO) technique applied to a GPS receiver on the International Space Station (ISS) will be useful for characterisation of this process. Our initial assessment presented here, addresses the question if severe storms leave a significant signature in RO profiles in the upper troposphere/lower stratosphere (UT/LS). The result is positive, suggesting that the bending angle of a GPS signal contains interesting information on the atmosphere around the tropopause. The presentation is focused on one particular Tropical Cyclone (TC), the hurricane Bertha, which formed in the Atlantic Basin during July 2008 and reached a maximum intensity of Category 3.