HR: 0830h
AN: A41C-03    [Abstracts]
TI: The Thermodynamic Structure of the Saharan Air Layer Simulated in the NCEP/NCAR Reanalysis
AU: * Wong, S
EM: swong@atmos.umd.edu
AF: ESSIC, University of Maryland, 2207 CSS Building #224, College Park, MD 20742 United States
AU: Dessler, A E
EM: dessler@atmos.umd.edu
AF: ESSIC, University of Maryland, 2207 CSS Building #224, College Park, MD 20742 United States
AB: The propagation of the Saharan air layer (SAL) across the tropical North Atlantic Ocean during boreal summer is related to the atmospheric variability associated with the African easterly wave. There is evidence showing the suppression of tropical cyclone (TC) activity that encounters the SAL. A model that does not appropriately simulate the SAL will therefore tend to overestimate the intensity of TCs that are interacting with the SAL. In this study, we apply the dust amount observed in the Moderate Resolution Imaging Spectrometer (MODIS) as a proxy to track the location of the SAL. Composites of NCEP/NCAR reanalysis temperature and moisture profiles are constructed to illustrate the thermodynamic structure of the SAL simulated in the reanalysis data. Comparison of the thermodynamic structure of the simulated SAL in the eastern and central tropical North Atlantic with the known sounding structure of the SAL can evaluate the ability of using reanalysis data to study the climatic effects of the SAL. Finally, principle component analysis (PCA) is applied to the reanalysis temperature at 850 hPa for August-September 2002 to identify the low-level temperature variation associated with the African easterly wave. The geographical pattern of the warm anomalies will then be compared with available MODIS daily observations of dust distribution for the same period as an evaluation of the propagation of the SAL simulated in the reanalysis data.
DE: 1610 Atmosphere (0315, 0325)
DE: 1620 Climate dynamics (3309)
DE: 3319 General circulation
DE: 3337 Numerical modeling and data assimilation
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly