Daniel Kirshbaum's webpage
Orographic and island precipitation in the tropics
Main collaborators: Ron Smith (Yale) Frank Robinson (Yale) Steve Sherwood (UNSW)
Tropical islands generally receive far more precipitation than the surrounding open ocean. This precipitation enhancement can arise from a number of different mechanisms. For example, the lower heat capacity of land compared to water causes it to warm faster during the day, which leads to convergent circulations and vertical ascent that can initiate deep convection. Orographic effects are also important over tropical islands, which often rise high above the sea. Baroclinicity associated with elevated heating drives convergent motions that may enhance the preexisting island convergence, and forced lifting and/or blocking of trade-wind flow can trigger frequent convective squalls.
Our study of island convection is currently focused on Dominica, a narrow and mountainous island that lies in the trade-wind belt of the eastern Caribbean sea. Using operational radar data from surrounding islands (courtesy of Meteo-France), along with a transect of tipping-bucket rain gauges across the high terrain, the characteristics of the island rainfall enhancement has been observed from 2007-2009. These observations are completed by large-eddy simulations (see figure below), which capture the mechanisms behind the island flow modification.
An NSF-funded field programme led by Ron Smith of Yale University is planned for early 2011 to study the convective processes over Dominica through in situ observations.
Please see my publications page for a full list of my publications.
Last updated 28th Feb 2010