Radiative-Dynamical Consequences of Dry Tongues in the Tropical Troposphere

Publisher Website
Google Scholar
Abstract
Dry layers are frequently observed in atmospheric soundings from the climatologically humid western Pacific warm pool region. Some 2400 soundings from the TOGA COARE field program were objectively examined for humidity drops (layers in which relative humidity decreases rapidly with height), indicative of the bases of dry layers. These occur throughout the lower and middle troposphere, with frequency peaks near 550 (the 0°C level), 800, and 950 mb. A composite constructed from these sounding data indicates the following. Almost all dry layers are too dry (and not warm enough) to be interpreted as conservative vertical displacements. Rather, they apparently consist of filaments or tongues of low moist static energy air advected into the column, often from the subtropics. Dry tongues are anomalously virtually warm near their bases with a slight cool layer below; that is, they sit atop sharp stable layers or inversions. The authors hypothesize that radiation is responsible for the thermal structure o... Abstract Dry layers are frequently observed in atmospheric soundings from the climatologically humid western Pacific warm pool region. Some 2400 soundings from the TOGA COARE field program were objectively examined for humidity drops (layers in which relative humidity decreases rapidly with height), indicative of the bases of dry layers. These occur throughout the lower and middle troposphere, with frequency peaks near 550 (the 0°C level), 800, and 950 mb. A composite constructed from these sounding data indicates the following. Almost all dry layers are too dry (and not warm enough) to be interpreted as conservative vertical displacements. Rather, they apparently consist of filaments or tongues of low moist static energy air advected into the column, often from the subtropics. Dry tongues are anomalously virtually warm near their bases with a slight cool layer below; that is, they sit atop sharp stable layers or inversions. The authors hypothesize that radiation is responsible for the thermal structure o...

This publication has 0 references indexed in Scilit: