Accession Number : ADA249839


Title :   An Observational Study of a Prefrontal Convective Rainband Using Tamex Single-and Dual-Doppler Data


Descriptive Note : Master's thesis,


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH


Personal Author(s) : Beeson, Michael R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a249839.pdf


Report Date : Jan 1991


Pagination or Media Count : 115


Abstract : The kinematic structure of a prefrontal rainband that caused heavy rainfall over Northern and Central Taiwan on 25 June 1987 was investigated using TAMEX single-and dual-Doppler data. Fields of winds and reflectivity were derived in a 50 km by 50 km grid using an objective analysis scheme with 1 km grid spacing in three directions. Vertical velocities were computed from the analastic continuity equation by integrating downward with variational adjustment. Results showed that the convective activity in the prefrontal region was deep with moderate intensity and heavy rainfall. The convective activity over the front was weak and confined to the lower layers, and rainfall decreased dramatically after the frontal passage. Vertical motions below 2 km were weak and were mostly caused by lifting along the frontal slope. In the prefrontal area the vertical motions were stronger and extended to higher levels. The eastern part of the frontal system lagged behind due to the influence of the Central Mountain Range, causing a curved front. The flow was from rear-to-front at all levels, except for the part near the coastline, where front-to-rear flow was seen at lower levels. In the lower levels a strong southwesterly Monsoon flow supplied the inflow of moist air, and strong veering with height was seen. The slow movement of the system, the orientation of the rainbands, and the terrain effects combined to produce periods of very heavy rainfall on the west coast of Central Taiwan.


Descriptors :   *MONSOONS , *CONVECTION(ATMOSPHERIC) , *TAIWAN , *RADAR METEOROLOGY , *RAINFALL , INTENSITY , THESES , TERRAIN , REGIONS , MOUNTAINS , RAIN , FLOW , CONTINUITY , REFLECTIVITY , HEIGHT , DOPPLER RADAR , STRUCTURES , GRIDS , FRONTS(METEOROLOGY) , KINEMATICS , VELOCITY


Subject Categories : Meteorology


Distribution Statement : APPROVED FOR PUBLIC RELEASE