89th American Meteorological Society Annual Meeting

Sunday, 11 January 2009
Analysis of daily monsoonal wind circulations in the lower troposphere over Estación Obispo, Mexico using wind profilers and the Gulf Surge Index
Phoenix Convention Center
Sandra Leticia Diaz, NCAR/SOARS, Boulder, CO; and L. M. Hartten
The North American Monsoon dominates over northwest Mexico during the summer and many people both depend on and can be endangered by the increasing rains associated with monsoons. General circulation models have not been able to accurately simulate monsoonal rains due to the poor representation of lower-tropospheric wind circulations. This project utilizes wind profiler data from the North American Monsoon Experiment for a better understanding of land/sea breeze characteristics and daily cycles. The 915-MHz wind profiler data is obtained from the 2005 North American Monsoon Experiment ‘supersite' along the coast of northwest Mexico near the mouth of the Gulf of California. Results show that 36 out of 58 days had sea breezes. Sea breezes in August occurred less often than in July or September. Before this “break”, prevailing winds were from the southeast going into the sea breeze, while after the “break” northwesterlies transitioned into the sea breeze. Sea breezes for the summer of 2005 commonly occurred from ~12:00PM to ~5:00PM LT. Finally, when hourly wind direction is plotted along with hourly Gulf Surge Index values there is no obvious relationship between surge events and occurrences of sea breezes. This new understanding of the lower-tropospheric wind patterns over northwestern Mexico will help monsoon forecasters evaluate the monsoon prediction models' likeness to real-time observations.

Supplementary URL: