Evolution of a Southeast Australian Coastally Trapped Disturbance |
| |
Authors: | C J C Reason K J Tory P L Jackson |
| |
Institution: | (1) School of Earth Sciences, University of Melbourne, Parkville, Australia, AU;(2) Environmental Studies, University of Northern British Columbia, Prince George, Canada, CA |
| |
Abstract: | Summary The southeast Australian coastally trapped disturbance (CTD) of 9–11 November 1982 that was previously studied by Holland
and Leslie is re-visited. Additional observational data not considered by these authors and a numerical simulation using the
Colorado State University Regional Atmospheric Modeling system (RAMS) are used for this purpose. Following initiation of the
event on the south coast, mesoscale ridging propagated along the east coast to just north of Brisbane. Associated with the
arrival of the event were a marked increase in surface pressure, drop in temperature and a shift and strengthening of the
wind. While the simulation does not appear to capture the details of the boundary layer as well as one would like, it does
represent the main features of the event, including the speed of propagation along the coast, reasonably well. Similar to
the observed, the model event shows gravity current-like characteristics.
The significance of topographic variability (e.g., large gap in the coastal mountains at the Hunter Valley) is considered.
It is suggested that the topography and ambient stratification in southeastern Australia are less favourable for CTD occurrence
than those in southern Africa and western North America where these systems have been extensively studied. Consequently, when
CTD do occur in southeastern Australia, the less pronounced topography and weaker stratification may enable local effects
to mask the CTD signal to some extent, thereby posing challenges in observation and forecasting.
Received March 2, 1999 |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|