Synoptic Scale Sensitivity of TIROS-N Moisture Channels in the Tropics
Abstract
Water vapor radiance data obtained from a satellite borne radiometer were evaluated for synoptic information content and accuracy over the tropical eastern Pacific Ocean. An upper moist layer was defined in terms of precipitable water by integrating sounding data downward from 300 mb. The varying pressure of this upper moist layer was correlated with collocated 6.7 and 7.3 micrometers water vapor brightness temperatures (BT)s. A persistent cluster of elevated BTs was observed over the subtropical Pacific adjacent to the western flank of a series of moisture bursts. Collocated rawinsonde soundings and satellite BTs consistently showed excellent agreement within this region, indicating extreme dryness in the middle and upper troposphere. The anomalous lack of upper tropospheric moisture, the tight clustering of abnormally large BTs, and the close proximity to a large area of active convection suggests these elevated BTs occur only as an occasional synoptically induced feature. Estimation of the influence of horizontal moisture advection on local BT changes resulted in maximum values of the same order of magnitude as the maximum observed BT changes. However, comparisons of these magnitudes at individual grid points showed little similarity. Theses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA196686
Entities
People
- Keith G. Blackwell
Organizations
- Air Force Institute of Technology