Wednesday, February 09, 2011
Spatial grids for hurricane climate research
We demonstrate a new framework for studying hurricane climatology. The framework consists of a spatial tessellation of the hurricane basin using equal-area hexagons. The hexagons are efficient in covering hurricane tracks and provide a scaffolding to combine attribute data from tropical cyclones with spatial climate data. The framework's utility is demonstrated using examples from recent hurricane seasons. Seasons that have similar tracks are quantitatively assessed and grouped. Regional cyclone frequency and intensity variations are mapped. A geographically-weighted regression of cyclone intensity on frequency and SST (results shown here) emphasizes the importance of a warm ocean in the intensification of cyclones over regions where the heat content is greatest. The largest differences between model predictions and observations occur near the coast. The framework would be ideally suited for comparing tropical cyclones generated from different numerical simulations (see U.S. CLIVAR hurricane working group). The hexagons have equal area and are plotted on a map using the Lambert conformal conic projection with standard parallels of 23 and 38 degrees.