New meteorological data resources suitable for the next generation of air quality models

During the last decade, the National Weather Service modernization program invested several billion dollars in upgrading the nation's weather observationa, telecommunication and numerical prediction infrastructure. At the same time, there were dramatic advances in high performance desktop computing allowing many organizations to run advanced meteorological and dispersion models, both of which are highly sensitive to the quality of their meteorological inputs. Many newer dispersion models, typified by Urban Airshed, Models 3, CALMET and point source codes such as AERMOD, can utilize more advanced meteorological information that has been the traditional practice. Rather than employing distant NWS observations or on-site data with restricted vertical coverage, it is deemed advantageous to use data extracted from gridded meteorological fields produced by either the NWS and/or regional models. As part of its daily operations, the NWS continuously assimilates all available meteorological observations into 3-D analyses on scales of 40 km or less. These analyses can yield pseudo-soundings capable of driving most new regulatory dispersion models. Moreover, the NWS gridded fields can themselves serve as the bases for reanalyses onto much finer grids (sub 10 km) which may incorporate additional data (aerometric network, sodar and profiler winds, etc.). SSESCO/FMA's Environmental Data Information Services (EDIS) have been routinely archiving and cataloging all relevant NWS data and products for several years to serve the needs of the dispersion modeling community. In addition to gridded fields, digital satellite data of value to photochemical modelers are also available.

In a parallel development, FMA is running the MM5 meteorological model in a continuous mode using a sub 3-km horizontal mesh driven by an advanced initialization system employing satellite (and eventually radar) data. Model output are archived onto DVD disks. The Front Range Modeling Consortium will permit users access to a fine scale, 3-D digital climatological database of the atmosphere within the airshed stretching from Colorado Springs to Cheyenne WY. These files can be reformatted as input into target air quality models. Such a resource should greatly facilitate the running of air quality models in the region by various modeling groups by providing ready access to high quality gridded meteorological data.