Extended Abstract (596K)P2.27
DIURNAL VARIABILITY OF SATELLITE DERIVED PRECIPITABLE WATER IN THE AMAZON BASIN
Tracy L. DeLiberty, Univ. of Delaware, Newark, DE; and J. A. Callahan
The Amazon Basin plays a pivotal role in the functioning of the global hydrology and climate system. Its abundant rainfall feeds the largest freshwater stream in the world, and the release of latent heat associated with rainfall makes the overlying atmosphere one of the most powerful fuel boxes driving the general circulation. Atmospheric water vapor is an important link connecting various components of the hydrological cycle and one of the less studied components in comparison to precipitation and river discharge. Biomass burning and deforestation activities in recent decades are raising concerns of its effect on water vapor transport and local recycling of moisture.
This study provides a bridge between site-specific observational studies and large-scale modeling experiments or data assimilation analysis to present a regional scale view of the temporal and spatial variability of precipitable water across the Amazon Basin. Remote sensing from satellites offers the opportunity to examine atmospheric water vapor at higher temporal and spatial resolution than conventional radiosonde measurements or large-scale data assimilation products.
A climatology of atmospheric moisture is assembled from two large-scale datasets using NCEP/NCAR and NVAP data to provide a baseline reference for comparison of seasonal and interannual variations and identify anomalous areas within the basin. A physical split-window technique (PSW) estimates atmospheric water vapor from geostationary imagery at a three-hour temporal interval for two months during 1988 and 1995. Spatially continuous fields are then generated during the daylight hours using a geographic information system. The diurnal and seasonal variations are examined along with the spatial variability across the Amazon Basin.
Poster Session 2, Climatology and Long-term Satellite Studies
Monday, 15 October 2001, 2:15 PM-4:00 PM
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