HR: 1330h
AN: A42B-0765    [PDF]
TI: An Analysis and Model Evaluation of the Marine Boundary Layer Height in the Eastern Pacific
AU: * Brunke, M A
EM: brunke@atmo.arizona.edu
AF: Department of Atmospheric Sciences, The University of Arizona, 1118 E. 4th St. P.O. Box 210081, Tucson, AZ 85721 United States
AU: Zeng, X
EM: xubin@gogo.atmo.arizona.edu
AF: Department of Atmospheric Sciences, The University of Arizona, 1118 E. 4th St. P.O. Box 210081, Tucson, AZ 85721 United States
AU: Zhou, M
EM: mingyuzhou@yahoo.com
AF: National Research Center for Marine Environmental Forecasts, No. 8 Da Hui Si Haidan District, Beijing, 100081 China
AU: Fairall, C
EM: Chris.Fairall@noaa.gov
AF: National Oceanic and Atmospheric Administration, Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Bond, N A
EM: bond@pmel.noaa.gov
AF: National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115 United States
AU: Lenschow, D H
EM: lenschow@ncar.ucar.edu
AF: National Center for Atmospheric Research, Mesoscale and Microscale Meteorology Division, P.O. Box 3000, Boulder, CO 80307 United States
AB: The atmospheric boundary layer (ABL) couples ocean surface processes with clouds and convection over the eastern Pacific. The determination of the boundary layer height is therefore crucial in the parameterization of the ABL in numerical weather prediction and climate models. Here, a method to determine the boundary layer height h objectively for clear and cloudy conditions and for stable and unstable cases from sounding data is developed. Using this technique, h is thus determined from about 1000 radiosondes taken between 1995 and 2001 during 11 cruises in the eastern Pacific Ocean. An analysis of this data reveals seasonal, interannual, meridional, and zonal variations in h in the cold tongue region, the intertropical convergence zone, and the subtropical stratocumulus region off of the coasts of California and Mexico. Furthermore, it will be shown that this method can also be used in other regions such as the central and western Pacific and over land. Additionally, the marine boundary layer height in the eastern Pacific determined by the Community Climate System Model version 2 (CCSM2) is compared to the objective h determined from radiosondes. Both model results and output from an offline version of the model's parameterization are overall underestimated. It is thus found that a doubling of the model's resolution in approximately the lowest 2 km (from 5 to 10 layers) as well as the adjustment of h within clouds to cloud base or top would significantly improve the determination of h by the model.
DE: 3307 Boundary layer processes
DE: 3309 Climatology (1620)
DE: 3374 Tropical meteorology
DE: 3394 Instruments and techniques
DE: 9355 Pacific Ocean
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting