Abstract

The North American Monsoon dominates over northwest Mexico during the summer and many people both depend on and can be endangered by increasing rains. Atmospheric General Circulation models have not been able to accurately simulate monsoonal rains due to the poor representation of lower-troposphe... Show moreThe North American Monsoon dominates over northwest Mexico during the summer and many people both depend on and can be endangered by increasing rains. Atmospheric 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 2004-2006 summers 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. Even though in previous work sea breezes are clearer in the seasonal mean, 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. Plots of all sea breezes for the summer of 2005 show a common existence from ~12:00PM to ~5:00PM LT. Finally, when hourly wind direction is plotted along with hourly Gulf Surge Index values they show 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. Show less