Recorded presentation10.2
The structure of the moist troposphere from COSMIC radio occultation signals
Sergey Sokolovskiy, UCAR, Boulder, CO; and C. Rocken, D. Lenschow, Y. H. Kuo, R. Anthes, W. Schreiner, D. Hunt, and P. Guo
The structure of the moist troposphere is characterized by stable horizontally extended layers accompanied by significant changes of humidity across the layers, and temperature inversions (the top of the atmospheric boundary layer (ABL), as well as other inversion layers in the free troposphere). In the presence of convective clouds, the moist troposphere is characterized by turbulence generated by latent heat release. In this study we use the COSMIC radio occultation (RO) signals transformed from time or space to impact parameter representation for monitoring these tropospheric structures. The phase of the transformed RO signal is sensitive to the mean vertical refractivity gradients (inversion layers), while fluctuations of the amplitude of the transformed RO signal indicate turbulence (moist convection). In the presence of a strong capping inversion, the turbulence is commonly limited by the inversion, while in the absence of an inversion, moist convection can penetrate to large heights in the troposphere. Monitoring of both the inversion layers and the convective layers in the troposphere is important for understanding processes of convective transport in the troposphere, weather forecasts including storm development, aircraft operations, and radio wave propagation. Despite their importance, inversions and convective layers are not always well reproduced by atmospheric models, due in part to the lack of global observations possessing sufficiently high vertical resolution. RO observations, with their high vertical resolution, can play an important role in identifying these layers. The six COSMIC satellites, which record L1 GPS RO signals in the troposphere in the open-loop mode, enable retrieval of the atmospheric profiles almost down to the surface, providing a unique opportunity for global observations of inversion layers and moist convection in the troposphere. Recorded presentation
Session 10, Data Impacts: Cosmic Observations and Applications-II
Wednesday, 23 January 2008, 10:30 AM-12:00 PM, 204
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