HR: 1340h
AN: A43C-0072    [Abstracts]
TI: Reanalysis of HOx Model Predictions Versus Observations: Adequacy of Modeling Approaches
AU: * Olson, J R
EM: Jennifer.R.Olson@nasa.gov
AF: NASA Langley Research Center, Chemistry and Dynamics Branch, Mail Stop 401B, Hampton, VA 23681 United States
AU: Crawford, J H
EM: James.H.Crawford@nasa.gov
AF: NASA Langley Research Center, Chemistry and Dynamics Branch, Mail Stop 401B, Hampton, VA 23681 United States
AU: Chen, G
EM: gao.chen-1@nasa.gov
AF: NASA Langley Research Center, Chemistry and Dynamics Branch, Mail Stop 401B, Hampton, VA 23681 United States
AU: Brune, W H
EM: brune@essc.psu.edu
AF: Penn State, Department of Meteorology 505 Walker Building, University Park, PA 16802 United States
AB: A unified analysis of the body of HOx observations from the Penn State Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) instrument is presented. Although prior analyses of individual field campaigns have been beneficial in revealing important components of the HOx budget previously neglected or unrecognized, a single integrated analysis is now desirable to establish consistency between data sets and the modeling approach. This analysis makes use of early HOx data sets that have been adjusted with minor corrections to the measurements to account for the evolution of understanding of instrument sampling characteristics. Additionally, a single photochemical model with current reaction rates is used for the predictive analysis. Results are examined for consistent trends in model/measurement agreement related to budget parameters such as HOx primary production. Trends are also inspected for possible artifacts related to parameters such as the solar zenith angle, or in the modeling approach itself. Under specific conditions, we show that extreme air mass heterogeneity can have a profound impact on conclusions regarding HOx dependencies on NOx concentrations. For these conditions (e.g. flights through aircraft contrails) the typically used 1-minute data average is not adequate, and the data analysis must proceed using much shorter time resolutions (e.g. 1-second). Other environmental conditions contributing to air mass heterogeneity at smaller time and spatial scales are examined for similar influences on the analysis.
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting