Masters Thesis Abstract: Ali Shareef
Analysis of mesoscale flow regimes over the Maldives using a numerical model
Maldives is an archipelago of low lying islands in a double chain of coral atolls spanning between 1o S and 8o N situated in the southern Indian Ocean (maximum elevation 2m above sea level). The climate regime of these islands is described as monsoonal. The dry season known as the northeast monsoon (NE monsoon) goes from December to February and the wet season known as the southwest monsoon (SW monsoon) goes from May to September. These islands experience the severe weather events such as severe thunderstorms and flooding associated with them. Not much is known or has been studied about the mesoscale weather patterns around Maldives.
Due to the paucity of observational data in the Indian Ocean, numerical models are used to study the mesoscale phenomena. In this research, the Weather Research and Forecast (WRF) model of Pennsylvania State University and the Regional Atmospheric Modelling Systems (RAMS) of Colorado State University are used.
WRF model is used with 5 nested domains of 27, 9, 3, 1 km and 250 m resolution. As a case study, a severe day with a downfall of more than 100 mm, in the central and southern atolls is simulated. The model predicted the synoptic situation reasonably well. Precipitation associated with convergence at the lower levels was observed in “streets” along with the wind pattern in the finest domain. Another simulation with no land mass was carried to verify if the input island is having any effect on the circulations. Currently the ongoing work is, using the RAMS model to conduct idealised runs.