Beta gyres in global analysis fields |
| |
| Authors: | Sun-Hee Kim H Joe Kwon R L Elsberry |
| |
| Institution: | Department of Atmospheric Sciences/Typhoon Research Center, Kongju National University, Kongju, Chungnam, 314-701 Korea,Department of Atmospheric Sciences/Typhoon Research Center, Kongju National University, Kongju, Chungnam, 314-701 Korea,Department of Meteorology, Naval Postgraduate School, Monterey, CA 93943, USA |
| |
| Abstract: | A three-component decomposition is applied to global analysis data to show the existence of a beta
gyre, which causes Tropical Cyclone (TC) to drift from a large-scale environmental steering current. Analyses
from the Global Data Assimilation and Prediction System (GDAPS) of the Korea Meteorological Administration (KMA),
the Global Forecast System (GFS) of NCEP, and the Navy Operational Global Atmospheric Prediction System (NOGAPS)
are used in this study.
The structure of the beta gyre obtained in our analyses is in good agreement with the theoretical structure,
with a cyclonic circulation to the southwest of the TC center, an anticyclonic circulation to the northeast,
and a ventilation flow directed northwestward near the center. The circulation of the beta gyre is strongest
at the 850-hPa level where the cyclonically swirling primary circulation is strongest, and decreases with
height, in a pyramid shape similar to the primary circulation. The individual structure of the beta gyre is
case- and model-dependent. At a certain analysis time, one model may clearly reveal a well-defined beta gyre,
but the other models may not. Within one model, the beta gyre may be well defined at some analysis times,
but not at other times. The structure of the beta gyre in the analysis field is determined by the nature of
the vortex initialization scheme and the model behavior during the 6-h forecast in the operational data
assimilation cycle. |
| |
| Keywords: | tropical cyclone beta gyre GDAPS GFS NOGAPS TCM-90 final analyses |
| 本文献已被 维普 SpringerLink 等数据库收录！ |
| 点击此处可从《大气科学进展》浏览原始摘要信息 |
| 点击此处可从《大气科学进展》下载免费的PDF全文 |
|
