HR: 0800h
AN: A31A-02    [Abstracts]
TI: Role of Mesoscale Convective Systems During Gulf of California Moisture Surges
AU: * Mejia, J F
EM: john.mejia@noaa.gov
AF: CIMMS/University of Oklahoma, National Weather Center 120 David L. Boren Blvd., Norman, OK 73072, United States
AU: Douglas, M
EM: michale.douglas@noaa.gov
AF: NSSL/NOAA, National Weather Center 120 David L. Boren Blvd., Norman, OK 73072, United States
AB: This paper studies the influence of organized convective activity in modulating moisture surges that develop during the North American Monsoon System along the Gulf of California using a multiyear set of surge events. As seen in different observational case studies during the North American Monsoon Experiment, multiple effects can be present simultaneously, which constitutes a challenge in identifying surges based on their forcings because they may have occurred as a superposition of forcing effects. A surge classification technique will be developed to discriminate surge events based on the convective activity taking place during the surge lifetime in different sector along the Gulf of California. The occurrence of organized convection in the form of Mesoscale Convective Systems (MCS's) can be identified by using cloud top temperature thresholds from International Satellite Cloud Climatology Project (ISCCP) products (this data consist of a 23 years of GOES imagery with 10km horizontal resolution at 3-hourly intervals available from 1983). Using direct inspection of the observations and other systematic approaches (such as discriminant analysis) permits stratifing the surges that are synoptically forced by either TEW's, TCs, or MCS events; the later presumably triggers or impacts surges more locally. Mean surge environments are composed by surge type using the NCEP North American Regional Reanalysis (NARR) products available from 1979 to the present at 3-hourly periods with horizontal resolution of 32 Km. Validation of the NARR are performed using NAME data sets (e.g. using aircraft data) in order to examine its utility as a diagnostic tool in the composites. The time resolution used to identify and diagnose surges, permits an exploration of the surge lifetime and diurnal variability. The large-scale dynamics acting of the surge will be revised and quantified for the different types of forcing. The results highlight the relative impact on the wind field produced by MCSs in the surge evolution.
DE: 3314 Convective processes
DE: 3329 Mesoscale meteorology
DE: 3374 Tropical meteorology
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly