ARL Begins Mississippi Coastal Atmospheric Dispersion Study

NOAA Air Resources Laboratory (ARL) scientists are collaborating with researchers from the Jackson State University (JSU) Trent Lott Geospatial Visualization and Research Center on a joint investigation of atmospheric dispersion, the Mississippi Coastal Atmospheric Dispersion Study (MCADS). The week-long study will begin June 15 in Gulfport, MS and focus on the prediction of pollutant plume movement and dispersal in the coastal environment using regional ensemble models or multi-model ensemble systems. A suite of instruments at two inland monitoring stations will measure ground-level ozone, sulfur dioxide, nitric acid, and fine particulate matter (PM2.5), while portable upper air sounding systems and Doppler sodar will be deployed to measure planetary boundary winds and temperatures. The planetary boundary is the mixed layer of the atmosphere closest to the ground that is influenced by many factors, including local topographical features, surface type, large-scale weather patterns, and cloud cover. In coastal areas, inland transport of marine air may significantly affect the temporal and spatial development of the mixed layer. The MCADS will develop a regional (and coastal) meteorological evaluation database for the Weather Research and Forecasting model and will explore the development of planetary boundary layer mixing height during sea breeze conditions. This study also allows ARL to prepare for a large air quality and climate field study planned in California in 2010 (CalNex 2010).

Background: The research partnership between ARL and the JSU Trent Lott Center to investigate coastal environment meteorology builds upon earlier ARL studies of coastal dispersion, such as those at Cape Canaveral (FL) and Vandenberg Air Force Base (CA). While these studies significantly improved the understanding of sea breeze regimes, there remains a need to better understand the evolution of the planetary boundary layer and the dynamics of sea breeze circulations. Two existing MCADS monitoring stations will be joined by an additional 4 stations installed along US Route 49 to provide a dense north-south surface observation network. The timing of the field study (mid-June), optimizes the probability of observing sea breeze conditions, as well as facilitates participation of a large student cadre from Jackson State University.

Significance: A large proportion of the nation’s population lives within reach of the local sea breeze (as far as 30 km inland).The MCADS study will enhance NOAA’s provision of accurate and timely dispersion forecasts associated with the need to protect the public in the event of a release of harmful materials into the air. The MCADS observations and research will directly benefit efforts of the National Weather Service and the broader meteorological research community to develop ensemble forecasting methods.

For More Information, contact:

Will Pendergrass