Open AccessShape measures of rain shields as indicators of changing environmental conditions in a landfalling tropical storm
Author(s) -
Matyas Corene
Publication year - 2008
Publication title -
meteorological applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 59
eISSN - 1469-8080
pISSN - 1350-4827
DOI - 10.1002/met.70
Subject(s) - tropical cyclone , environmental science , extratropical cyclone , meteorology , atmosphere (unit) , storm , landfall , rainband , shield , climatology , geology , geography , petrology
The atmosphere and land surface can alter the structure of a landfalling tropical cyclone (TC), resulting in complex spatial patterns of rainfall. Rather than average observations from many TCs, this study utilizes a Geographic Information System (GIS) to spatially analyse radar reflectivity data that define the rain shield of TC Dennis (1999). The effects of the atmosphere and land surface upon the rain shield are quantified through the calculation of six shape metrics: areal coverage, elongation, compactness, fragmentation, orientation, and distance and bearing of the polygon centroid from the storm circulation centre. Analysis of the data in hourly intervals reveals the extent to which the landfall process, vertical wind shear, dry air intrusion, interaction with mountains, and extratropical transition (ET) affect the location, size, and shape of the rain shield. Results illustrate the influences that multiple forcings can have upon TC structure and demonstrate that the calculation of the shape metrics can provide a method to evaluate the effects of environmental conditions upon multiple TCs. Copyright © 2008 Royal Meteorological Society