Simulation of the New England Sea Breeze: The Effect of Grid Spacing

Abstract

The fifth-generation Pennsylvania State University?National Center for Atmospheric Research (Penn State? NCAR) Mesoscale Model (MM5) was run for seven cases from 2001 in which a sea breeze develops along the eastern New England coast. The results from model runs with 36-, 12-, and 4-km grid spacing are compared with observations as well as output from the National Centers for Environmental Prediction (NCEP) Eta Model on a 40-km grid. As expected, analysis of the individual cases shows that the higher-resolution grids are able to resolve realistic details in the flow, details that the 36-km grids and the 40-km NCEP Eta Model miss entirely. Contrary to expectations, the error statistics show that the ability to forecast specific variables at specific locations does not improve very much when using higher resolution. Even more surprisingly, the 4-km grids produced the biggest errors in forecasting surface dewpoint.