Branch Seminar Series: Nikisa S. Jordan, Raymond M. Hoff, and Julio T. Bacmeister

CREST, Joint Center for Earth Systems Technology, University of Maryland Baltimore County
Preliminary work that compares the Planetary Boundary Layer (PBL) height produced by the version 5 Goddard Earth Observing System (GEOS-5) with Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) is presented. Part of GEOS-5 is a Global Circulation Model (GCM). The model utilizes the Lock et al. (2000) scheme to parameterize the PBL height. Prediction of quantities such as precipitation rates, cloud height, and chemical species concentrations at the surface are dependent on the estimated boundary layer parameter. Recently, developers have noted some anomalies in the PBL height predictions (Tassone et al. 2007). Thus, verification of PBL outputs from the model is extremely important. We have developed two PBL products for CALIPSO data based on (1) a wavelet technique and (2) a hybrid technique, which looks at the signal variability through the local standard deviation of the backscatter constrained by the magnitude of the backscatter itself. These results have been compared with radiosondes and ground-based lidar to justify the use of the techniques. Comparisons between the model parameter and satellite observations have been performed for regions over land and water for the western hemisphere in 2006. Lock, A. P., A. R. Brown, M. R. Bush, G. M. Martin, and R. N. B. Smith (2000). A new boundary layer mixing scheme. Part I: Scheme description and single column model tests. Mon. Wea.Rev., 128, 3187-3199. Tassone, C.M., J. T. Bacmeister, and L. L. Takacs (2007). The impact of the boundary layer parameterization on the weather and climate of the GEOS-5 model, AMS meeting- 19th Conference on Climate Variability and Change, Abstract 2A.9