Kinematic characteristics of air flowing into and out of precipitating convection over the west Pacific warm pool: An airborne Doppler radar survey

Citation
De. Kingsmill et Ra. Houze, Kinematic characteristics of air flowing into and out of precipitating convection over the west Pacific warm pool: An airborne Doppler radar survey, Q J R METEO, 125(556), 1999, pp. 1165-1207
Citations number
65
Categorie Soggetti
Earth Sciences
Journal title
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
ISSN journal
00359009 → ACNP
Volume
125
Issue
556
Year of publication
1999
Part
B
Pages
1165 - 1207
Database
ISI
SICI code
0035-9009(199904)125:556<1165:KCOAFI>2.0.ZU;2-0
Abstract
Air flowing into and out of 25 cloud systems over the west Pacific warm poo l was sampled by Doppler radars on board two NOAA WP-3D aircraft and the NC AR Electra aircraft during the Tropical Ocean/Global Atmosphere Coupled Oce an-Atmosphere Response Experiment (TOGA-COARE). In convective cells, updrau ght inflows and downdraught outflows tended to be positioned adjacent to ea ch other at sharp updraught-downdraught interfaces sloping at various angle s and directions. The updraught inflows were sometimes shallow and sometime s deep, often extending well above the boundary layer. Downdraught outflow magnitudes were usually stronger than updraught inflows, and the horizontal directions of the inflow and outflow were frequently offset from each othe r at angles of similar to\90 degrees\. In stratiform precipitation regions, the dominant airflow features were des cending mid-level inflows, located at the bases of anvils and often extendi ng into the interior of the precipitation system. These stratiform inflows originated at levels between 5 and 10 km and descended to about 3 km. A few extended down to the surface. Stratiform inflows were typically strong and sandwiched between weaker stratiform outflows at upper and lower altitudes . The stratiform-region inflow and outflow directions were frequently offse t by similar to\90 degrees\ in the horizontal. The mid-level inflow current s entered the stratiform regions horizontally from a direction similar to t hat of the large-scale ambient wind. The mid-level stratiform inflow tended to occur in the same vertical plane as the convective downdraught outflow, although the mid-level stratiform in flow appeared to be slowed by horizontal pressure gradients before connecti ng with the convective downdraught outflow. In other respects, the mesoscal e systems differed from a simplified two-dimensional model of airflow. The systems moved primarily by discrete propagation, and updraughts and downdra ughts tended to have orthogonal horizontal relative airflow.