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Data Analysis and Comparison between the Meteorological Tower and Acoustic Sounder in Lewiston, Idaho
P.I.: D. Koracin
Duration: May 96 - September 96
Agency: Idaho Department of Health and Welfare - Division of Environmental Quality, 1410 North Hilton, Boise, ID 83706-1255

The acoustic sounder in Lewiston (western Idaho) was operational for a limited time from 10 January to 9 July 1995, while the meteorological tower is in continuous operation at the same location. Besides generating detailed statistics and tables, the study provided a comparison between these two systems. Analysis of the comparison between the tower and the acoustic sounder data in Lewiston showed a fairly good agreement between these two different types of measurements. Correlation coefficients were generally between 0.7 and 0.8 for wind speed and between 0.6 and 0.7 for wind direction. A frequency distribution of the wind direction indicated the characteristics of the wind regime in the area, with significant westerly flow during the nighttime and more westerly than easterly flow during the day. Sodar also measured more frequent lower and higher wind speeds compared to tower measurements. The study also revealed that there is a possible technical problem with the sensor at 245 m AGL. All this information is needed to calculate the transport and dispersion of atmospheric pollutants in this area. The same method of analysis was applied to a sodar that was located in Pocatello from 18 December 1994 to 28 February 1995. The average wind speeds were generally less than 7 m/s and the dominant flows were southeasterly.

Initial Forecasting of Mesoscale Atmospheric Phenomena in the Truckee Meadows Basin Using a Numerical Model
P.I.: D. Koracin (P.I); M. Cairns (NWS) (co P.I.)
Duration: December 95 - May 96
Agency: University Cooperation for Atmospheric Research (UCAR) and National Oceanographic and Atmospheric Agency (NOAA) - COMET Program

The main objective of this study was to set up and evaluate a regional mesoscale numerical model for the prediction of the atmospheric flows in the complex topography of the Truckee Meadows basin and simulate a case study using data from an intensive field program and the available NWS network data. In order to provide a look at the mesoscale features in the Truckee Meadows basin, we used the Colorado State University's Regional Atmospheric Modeling System (RAMS). The RAMS model was run with a horizontal resolution of 1 km on the nested grid centered at Reno. The model results determined the level of the coupling of the basin flow with synoptic flow, which is a critical parameter for the study of winter inversions and stagnant conditions associated with significant impacts on the estimation of and prediction of air quality.

Characterization of Stable and Low Wind Speed Meteorological Conditions Conducive to Wintertime CO Buildup in the Truckee Meadows Basin
P.I.: D. Koracin (P.I.); D. Egami (co P.I.)
Duration: February 95 - June 95
Agency: Washoe County Health Department

The purpose of this study was to characterize the meteorological conditions that lead to high CO concentrations in the Truckee Meadows Basin. The primary objective of the proposed study was to characterize and explain the three-dimensional structure of the atmosphere in the Reno Basin during the buildup and disintegration of high wintertime CO episodes. As a second objective, model results provided realistic wind fields for possible input to urban air quality grid models such as UAM. The peak in CO concentrations usually does not correlate directly with the peak in CO emissions, a fact which we must attribute to local meteorology. Available information from the National Weather Service is based on synoptic observations and does not include small-scale topography and circulation patterns, which are essential mechanisms of the atmospheric flow in complex terrain. Upper flow is consequently less significant in its effects on local meteorology and air quality during conditions of winter inversion with low winds. Surface stations supply valuable information, but do not show the horizontal and vertical variability of wind, temperature and turbulence fields. The Regional/mesoscale Atmospheric Modeling System (RAMS) was used in this study to resolve topography and atmospheric features on a scale of 2-3 km. Model results determined the level of coupling of the basin flow with synoptic flow, which is a critical parameter for winter inversions and stagnant conditions associated with significant levels of CO concentrations. Simulated wind and temperature fields as well as inversion depth will be also used as an improved input for UAM modeling in a future step.

Modeling of Atmospheric Flow over Complex Terrain in Southern Idaho
P.I.: D. Koracin (P.I.); Judy Chow (co P.I.)
Duration: January 95 - September 96
Agency: Idaho Department of Health and Welfare - Division of Environmental Quality, 1410 North Hilton, Boise, ID 83706-1255

For the first time in studying the Pocatello non-attainment area, located in the complex terrain of southeast Idaho, two high-resolution atmospheric regional/mesoscale models (Regional Atmospheric Modeling System /RAMS/ and Mesoscale Model 5 /MM5/) were successfully applied to several cases of episodic high concentration of PM10. The models were evaluated using data taken during the field program in January 1995. The three-dimensional wind fields in this highly complex terrain, as generated by these numerical models, provided detailed input for the dispersion models. We used a Lagrangian particle dispersion model to simulate the transport and dispersion of the pollutants emanating from two large industrial sources with a variety of emission materials. The results from the atmospheric models indicated increased vorticity at the entrance to the Portnaeuf valley as well as the possible transport of pollutants toward Pocatello, both from the northwest and along the southern canyons. The Lagrangian particle model visualized recirculation at the entrance of the Portnaeuf valley and a return flow in the northeast-southwest direction. Another technique of tracing the pollution backward from the receptor to the most probable source area has also been used. The results showed that the smaller emission sources in complex terrain can contribute significantly to degradation of air quality allong the valleys due to the existence of the channeled and coherent plume. The outputs of the atmospheric numerical model were also reformatted and adjusted for use as input to the EPA-supported dispersion model CALPUFF, which can predict the formation of secondary aerosols.

Development of New Parameterization for Inhomogeneous Turbulence Structure in the Cloud-Capped Boundary Layer
P.I.: D. Koracin
Duration: December 94 - December 96
Agency: DRI - Instutional Project Assignment

Entrainment in the Cloudy Marine Atmosphere
P.I.: D. Koracin
Duration: January 92 - December 92
Agency: DRI - Instutional Project Assignment

Modeling the Dispersion of Vapor and Aerosol Particulates in the Atmospheric Boundary Layer
P.I.: S. Chai and D. Koracin (P.I.s)
Duration: May 98 - May 00
Agency: Department of Defense - DEPSCoR - Office of Naval Research
Budget: $216,859 (DoD:$144,572; Cost share: $72,287)

The Relationships Among Air Quality, Meteorology and Climate in an Arid Environment
P.I.: D. Lowenthal (P.I.); M. Wetzel and D. Koracin (co P.I.s)
Duration: September 94 - September 96
Agency: Envirnmental Protection Agency - EPSCoR Program

Improvement of the Microphysical and Radiation Components of the Regional Atmospheric Modeling System (RAMS)
P.I.: D. Mitchell (P.I.); D. Koracin (co P.I.)
Duration: October 93 - May 97
Agency: Department of Energy - Atmospheric Radiation Measurements Program

Transport and Dispersion of Atmospheric Pollutants from the Mohave Power Project (Colorado River Valley)
P.I.: J. Watson (P.I.); D. Koracin (supporting staff)
Duration: January 96 - December 96
Agency: Southern California Edison and EPA Project MOHAVE

Cloud Seeding Program over Sierra Nevada
P.I. Arlen Huggins (P.I.); D. Koracin (supporting staff)
Duration: January 96 - May 97
Agency: National Oceanic and Atmospheric Agency