HR: 13:40h
AN: A33F-01    [Abstracts]
TI: Chemical Data Assimilation in Support of Air Quality Forecasts
AU: * Carmichael, G R
EM: gcarmich@engineering.uiowa.edu
AF: The University of Iowa, CGRER 424 IATL, Iowa City, IA 52242 United States
AU: Chai, T
EM: tchai@cgrer.uiowa.edu
AF: The University of Iowa, CGRER 424 IATL, Iowa City, IA 52242 United States
AU: Tang, Y
EM: ytang@cgrer.uiowa.edu
AF: The University of Iowa, CGRER 424 IATL, Iowa City, IA 52242 United States
AU: Sandu, A
EM: asandu7@vt.edu
AF: Virginia Polytechnical University, Department of Computer Science, Blacksburg, VA 24061 United States
AU: Daescu, D
EM: daescu@pdx.edu
AF: Portland State University, Department of Mathematics, Portland, OR 97207 United States
AU: Seinfeld, J
EM: seinfeld@caltech.edu
AF: California Institute of Technology, Department of Chemical Engineering, Pasadena, CA 91125 United States
AU: Hess, P
EM: hess@ucar.edu
AF: National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307 United States
AU: Anderson, T
EM: tadand@u.washington.edu
AF: University of Washington, Department of Atmospheric Science, Seattle, WA 98195 United States
AB: Significant advancements have been made in recent years in our ability to measure and model atmospheric chemistry. Not only is our ability to characterize a fixed atmospheric point in space and time expanding, but the spatial coverage is also expanding through growing capabilities to measure atmospheric constituents remotely using sensors mounted at the surface, in aircraft, and from satellites. Our ability to model atmospheric chemistry has also advanced. In recognition of the role that aerosols play in radiation, meteorology/climate, and health impact areas, chemical transport models (CTMs) now include a detailed description of aerosol dynamics, and calculate size-resolved aerosol composition, and radiances. However, CTMs are often poorly constrained due to a variety of reasons including incomplete emissions information, and poorly parameterized processes. Improvements in our analysis capability requires a an intimate and close integration of modeled and measured quantities The close integration of observational data is recognized as essential in weather/climate analysis and forecast activities, and this is accomplished by meteorological data assimilation. In this paper we report on recent advances in chemical data assimilation. Results from studies aimed at implementing data assimilation techniques using recent field data will be presented. Results of analysis of the extensive field data obtained during the 2004 ICARTT study using our regional scale chemical transport model with chemical data assimilation will be presented. This research supports the ICARTT experiment by providing: 1) an evaluation of the quality of our 3-D regional-scale forecast of trace gas and aerosol distributions, and meteorological fields in support of the intensive aircraft measurements; 2) an updated evaluation of the experiment-specific emission products for primary aerosol and gaseous precursors, as well as preliminary results from inverse studies needed to increase the accuracy of the 3-d modeled trace gas and aerosol fields, and to aid in flight planning; and 3) analysis using a newly developed chemical data assimilation component of our regional model to produce 4-dimensional reanalysis fields using the ICARTT aircraft data, along with surface, ozonesonde, and satellite data. This presentation will focus on a) (briefly) the major finding and new results derived from items 1) and 2), above, and b) the new results and findings using our data assimilation system. We will demonstrate how this analysis can provide added value to the experiments by a closer integration of modeled and measured quantities, with the two merged together to provide a consistent and best estimate of the chemical state of the atmosphere. Reanalyzed distributions of select chemical species will be discussed. The potential use of these techniques to improve air quality forecasting will also be addressed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005