P1.4
Water vapor transport within the atmospheric boundary layer from Raman lidar, radiosondes, wind profiler, and tower observations
Mariana Adam, Howard University, Washington, DC; and T. Dejene, M. Hicks, M. Robjhon, B. B. Demoz, J. D. Fuentes, E. Joseph, D. Venable, and R. Connell
This study develops a method for studying water vapor transport through the atmospheric boundary layer based on Raman Lidar, Radiosonde, flux tower, and wind profiler observations obtained during WAVES (Water Vapor Variability – Satellite/Sondes experiment) conducted 2006 (summer), 2007 (summer), and 2008 (winter) at the Howard University Beltsville Campus. The method enables evaluation of the water vapor fluxes entering the sub-cloud layer, which has valuable application in mesoscale and cloud resolving model studies, and some climate related studies (e.g., concerning the formation and evolution of clouds in polluted air masses). Up to present, a number of studies have been conducted to evaluate the latent heat flux in the surface layer, using water vapor measurements from a scanning Raman lidar and Monin-Obukhov similarity theory. A few studies were conducted to evaluate the water vapor fluxes, using DIAL and Doppler lidars measurements and eddy covariance method to estimate fluxes. In this work, first, a wavelet technique is applied to the virtual potential temperature, aerosol backscatter coefficient, and water vapor mixing ratio derived from radiosonde and Lidar measurements, respectively to estimate the atmospheric boundary layer attributes (such as the depth of the mixed layer, stable boundary layer, and residual layer). Within the mixed layer average quantities such as specific humidity and virtual potential temperature are computed throughout the course of a day. Second, the water vapor fluxes are determined from the lidar data based on the gradient method. The eddy diffusivity is estimated both in time and vertical using information from derived meteorological quantities measured on a flux tower. Also, the flux is determined using one dimensional diffusion equation for water vapor specific humidity.
Poster Session 1, Poster: Advances in Lidar Applications
Wednesday, 14 January 2009, 2:30 PM-4:00 PM, Hall 5
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