Evaluations of NOx and highly reactive VOC emission inventories in Texas and their implications for ozone plume simulations during the Texas Air Quality Study 2006
Journal article, 2011
Satellite and aircraft observations made during the 2006 Texas Air Quality Study (TexAQS) detected strong urban, industrial and power plant plumes in Texas. We simulated these plumes using the Weather Research and Forecasting-Chemistry (WRF-Chem) model with input from the US EPA's 2005 National Emission Inventory (NEI-2005), in order to evaluate emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs) in the cities of Houston and Dallas-FortWorth. We compared the model results with satellite retrievals of tropospheric nitrogen dioxide (NO2) columns and airborne in-situ observations of several trace gases including NOx and a number of VOCs. The model and satellite NO2 columns agree well for regions with large power plants and for urban areas that are dominated by mobile sources, such as Dallas. How-ever, in Houston, where significant mobile, industrial, and inport marine vessel sources contribute to NOx emissions, the model NO2 columns are approximately 50 %-70 % higher than the satellite columns. Similar conclusions are drawn from comparisons of the model results with the TexAQS 2006 aircraft observations in Dallas and Houston. For Dallas plumes, the model-simulated NO2 showed good agreement with the aircraft observations. In contrast, the model-simulated NO2 is similar to 60 % higher than the aircraft observations in the Houston plumes. Further analysis indicates that the NEI-2005 NOx emissions over the Houston Ship Channel area are overestimated while the urban Houston NOx emissions are reasonably represented. The comparisons of model and aircraft observations confirm that highly reactive VOC emissions originating from industrial sources in Houston are underestimated in NEI-2005. The update of VOC emissions based on Solar Occultation Flux measurements during the field campaign leads to improved model simulations of ethylene, propylene, and formaldehyde. Reducing NOx emissions in the Houston Ship Channel and increasing highly reactive VOC emissions from the point sources in Houston improve the model's capability of simulating ozone (O-3) plumes observed by the NOAA WP-3D aircraft, although the deficiencies in the model O-3 simulations indicate that many challenges remain for a full understanding of the O-3 formation mechanisms in Houston.
wrf model
campaign
ensemble
industrial emissions
tropospheric no2
organic-compounds
monitoring instrument
column retrieval
houston
aerosol
field
Author
S. W. Kim
National Oceanic and Atmospheric Administration
University of Colorado
S. A. McKeen
University of Colorado
National Oceanic and Atmospheric Administration
G. J. Frost
University of Colorado
National Oceanic and Atmospheric Administration
S. H. Lee
University of Colorado
National Oceanic and Atmospheric Administration
M. Trainer
National Oceanic and Atmospheric Administration
A. Richter
Universität Bremen
W. M. Angevine
University of Colorado
National Oceanic and Atmospheric Administration
E. Atlas
University of Miami
L. Bianco
University of Colorado
National Oceanic and Atmospheric Administration
K. F. Boersma
Eindhoven University of Technology
Royal Netherlands Meteorological Institute
J. Brioude
National Oceanic and Atmospheric Administration
University of Colorado
J. P. Burrows
UK Centre For Ecology & Hydrology (UKCEH)
Universität Bremen
J. A. De Gouw
National Oceanic and Atmospheric Administration
University of Colorado
A. Fried
National Center for Atmospheric Research
J. Gleason
National Aeronautics and Space Administration (NASA)
A. Hilboll
Universität Bremen
Johan Mellqvist
Chalmers, Earth and Space Sciences, Optical Remote Sensing
J. Peischl
National Oceanic and Atmospheric Administration
University of Colorado
D. Richter
National Center for Atmospheric Research
Claudia Rivera
Chalmers, Earth and Space Sciences, Optical Remote Sensing
T. B. Ryerson
National Oceanic and Atmospheric Administration
S. T. L. Hekkert
Sensor Sense
J. G. Walega
National Center for Atmospheric Research
C. Warneke
National Oceanic and Atmospheric Administration
University of Colorado
P. Weibring
National Center for Atmospheric Research
E. Williams
National Oceanic and Atmospheric Administration
University of Colorado
Atmospheric Chemistry and Physics
1680-7316 (ISSN) 1680-7324 (eISSN)
Vol. 11 22 11361-11386Subject Categories (SSIF 2011)
Meteorology and Atmospheric Sciences
DOI
10.5194/acp-11-11361-2011