SCSMEX Update

William K. M. Lau
Climate and Radiation Branch
NASA/Goddard Space Flight Center
Greenbelt, MD 20771, USA


The South China Sea Monsoon Experiment (SCSMEX ) is a large scale international monsoon experiment jointly sponsored and endorsed by the WMO/M1 Committe of Atmospheric Sciences, WCRP CLIVAR Monsoon Program, Pacific Science Association. It involves the participation of all major countries and regions of East and Southeast Asian, as well as Australia and the US.

The objective of SCSMEX is:

SCSMEX consists of five components:

SCSMEX OPERATIONAL PLAN SUMMARY

The Intensive Observing Period (IOP) of the South China Sea Monsoon Experiment (SCSMEX) will be executed as planned for May 1 to July 31, in 1998. SCSMEX will be closely coordinated with the GEWEX Asian Monsoon Experiment (GAME). GAME-T will launch an land -atmosphere field campaign from April through August of 1998. It will provide one of the upstream wind and moisture conditions that precedes the onset of the SCS monsoon.

One of the most significant observational platform is the setting up of an intensive flux array (IFA) consisting of a dual Doppler radar pair for detailed rainfall measurements over the open water of the South China Sea, ISS system for measurement of winds and Atlas mooring for oceanic and flux measurements . Currently planned is the deployment of the TOGA radar on board a ship and the BMRC polarimetric radar on Dongsha island in the northern SCS, situated to the southwest of Taiwan and southeast of Hong Kong. The dual radar coverage will be collocated with an ATLAS buoy, which measures surface meteorology and subsurface oceanic temperature and salinity. Spatial rainfall information will be provided by the TRMM satellite overflying the area. This configuration will provide a unique validation platform for TRMM Ground truth. The radars will be operated for the entire period from May -1 to July 31 to provide continuously rainfall coverage over the selected site. Additional raingauges will be deployed on island in the vicinity of the IFA, to provide ground truth for radar and satellite rainfall estimation.

Enhanced upper air soundings of 4 times daily will be provided for stations surrounding the SCS. Hourly surface radiation will be maintained in all coastal as well as island sites over the SCS during the entire period of the experiment.

Aerosonde flights will be carried out during the IOP to take atmospheric soundings for temperature and moisture for various weather conditions including disturbed and undisturbed periods, before and after the monsoon onset.

Three Atlas moorings will be deployed in a line from Dongsha to the vicinity of Nansha at the center of the SCS, to monitor thermal structures in the upper ocean and their changes accompanying the onset of the SCS monsoon. During the IOP, two oceanic ships will be conducting oceanic surveys in the northern and southern part of the SCS and drifting buoys will be deployed to measure ocean currents.

An Operation Center will be set up in Guangzhou for coordinating the logistics of the field phase of SCSMEX. An operations plan for SCSMEX is being drafted. This plan will be put forward for endorsement by the international SCSMEX Organization Committee and the Science Steering Committee in an upcoming meeting to be held in Hong Kong in the middle of September, 1997.

A web site for SCSMEX is now under construction - http://www.joss.ucar.edu/joss_psg/project/scsmex/.

Comments and feedbacks are welcomed. For more information on SCSMEX please contact:

Dr. William K. M. Lau
Climate and Radiation Branch
NASA/Goddard Space Flight Center
Greenbelt, MD 20771, USA
E-mail: lau@climate.gsfc.nasa.gov


Dr. William K. M. Lau, Head
Climate and Radiation Branch
Code 913, NASA/GSFC
Greenbelt, MD 20771, USA
Tel: 301-286-7208
Fax: 301-286-1759
E-mail: lau@climate.gsfc.nasa.gov