Geoscience Reference
In-Depth Information
SATELLITE-OBSERVED 3D MOISTURE STRUCTURE
AND AIR-SEA INTERACTIONS DURING SUMMER
MONSOON ONSET IN THE SOUTH CHINA SEA
YONGSHENG ZHANG
International Pacific Research Center, SOEST,
University of Hawaii at Manoa, POST Bldg. 401,
1680 East-West Road, Honolulu, Hawaii 96822, USA
TIM LI
International Pacific Research Center and Department of Meteorology,
SOEST, University of Hawaii at Manoa, POST Bldg 401,
1680 East-West Road, Honolulu, Hawaii 96822, USA
In this chapter, water vapor and air temperature profiles observed by the
Atmospheric Infrared Sounder (AIRS), sea surface temperature (SST) and rain
rate observed by TRMM Microwave Imager (TMI), and QuikSCAT surface
wind for 2003-2006 are used to identify the 3D moisture structure and air-sea
interaction processes during the onset of the South China Sea summer monsoon
(SCSSM). Our analyses document an enhanced moisture accumulation in the
atmospheric boundary layer co-existing with the surface easterlies preceding
to the monsoon convection. Further analysis points out that, compared to the
warming of SST, the boundary layer convergence plays a more important role in
producing a warm and wet atmospheric boundary layer ahead of the monsoon
convection, which contributes greatly to the development and maintenance of
the northward propagation of the monsoon convection.
1. Introduction
As a semi-enclosed tropical sea surrounded by the Southeast-East Asian
landmass, the South China Sea (SCS) plays an important role in modulation
of climate anomalies in Asia. In middle May, accompanied by a switch of the
prevailing zonal wind from easterly to westerly, the onset of the SCS summer
monsoon (SCSSM) is characterized by an abrupt increase of precipitation
and an associated tropical convergence zone northward propagating from
the equator to northern SCS. The rainfall belt continues to move northward
and controls the central China and South of Japan in late May and early
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