HR: 1340h
AN: GC23A-1302 [Abstracts]
TI: Variations of Vegetation and Rainfall in Thailand
AU: * Chokngamwong, R
EM: rchoknga@gmu.edu
AF: George Mason University, SCS/CEOSR, MSN 5C3, ST1-Rm211
4400 University Dr, farifax, VA 22030
United States
AU: Chiu, L
EM: lchiu@@gmu.edu
AF: George Mason University, SCS/CEOSR, MSN 5C3, ST1-Rm211
4400 University Dr, farifax, VA 22030
United States
AU: Chiu, L
EM: lchiu@@gmu.edu
AF: GSFC/DISC, Code 610.2 NASA/GSFC/Data and Information Service Center
Greenbelt Road, Greenbelt, MD 20771
United States
AB:
While variations in vegetation are dependent on climatic factors such as rainfall and temperature, recent studies have shown
a possible feedback of changing surface conditions on climate. For example, Sarkar et al. (2005) show variations of Asian
summer monsoon rainfall is preceeded by vegetation changes in the spring over cultivated croplands. In this study, we
further examine this feedback over Thailand. Thailand daily rain data collected over 100 gauges are examined and compared
with gauge analyses provided by the Global Precipitation Climatology Center (GPCC). Climatologically, Thailand monsoon
rainfall is influenced by the prevailing seasonal wind direction. In the northern region, most rainfall occurs during JJA. In
the southern region rain occurs mostly in SON. Normalized Difference Vegetation Index (NDVI) derived from AVHRR for the
period 1982-2000 is used to examine the vegetation changes. The seasonal cycle of NDVI lags behind that of precipitation by
about 2-3 months. The non-seasonal changes in NDVI show minima in 1982 and 1992, which may be related to the volcanic
eruptions of El Chichon in Mexico in 1981 and Mt. Pinatubo in the Philippines in 1991, respectively. Aerosol indices such as
Aerosol Optical Depth (AOD) and Aerosol Index (AI) derived from the Total Ozone Mapping Spectrometer (TOMS) will be used to
delineate the effect of the volcanoes. Other non-seasonal effects, such as that due to the El Nino/Southern Oscillation
(ENSO) will be incorporated in our analysis.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1637 Regional climate change
DE: 1640 Remote sensing (1855)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005