Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region
Journal article, 2012
We evaluate the rates of secondary production and primary emission of formaldehyde (CH2O) from petrochemical industrial facilities and on-road vehicles in the Houston Texas region. This evaluation is based upon ambient measurements collected during field studies in 2000, 2006 and 2009. The predominant CH2O source (92 +/- 4% of total) is secondary production formed during the atmospheric oxidation of highly reactive volatile organic compounds (HRVOCs) emitted from the petrochemical facilities. Smaller contributions are primary emissions from these facilities (4 +/- 2%), and secondary production (similar to 3%) and primary emissions (similar to 1%) from vehicles. The primary emissions from both sectors are well quantified by current emission inventories. Since secondary production dominates, control efforts directed at primary CH2O emissions cannot address the large majority of CH2O sources in the Houston area, although there may still be a role for such efforts. Ongoing efforts to control alkene emissions from the petrochemical facilities, as well as volatile organic compound emissions from the motor vehicle fleet, will effectively reduce the CH2O concentrations in the Houston region. We do not address other emission sectors, such as off-road mobile sources or secondary formation from biogenic hydrocarbons. Previous analyses based on correlations between ambient concentrations of CH2O and various marker species have suggested much larger primary emissions of CH2O, but those results neglect confounding effects of dilution and loss processes, and do not demonstrate the causes of the observed correlations. Similar problems must be suspected in any source apportionment analysis of secondary species based upon correlations of ambient concentrations of pollutants.
carbonyls
ambient air
air-quality
stratosphere
airborne
statistical-analysis
emission inventories
nox
hydrocarbons
ozone formation
Author
D. D. Parrish
National Oceanic and Atmospheric Administration
T. B. Ryerson
National Oceanic and Atmospheric Administration
Johan Mellqvist
Chalmers, Earth and Space Sciences, Optical Remote Sensing
John Johansson
Chalmers, Earth and Space Sciences, Optical Remote Sensing
A. Fried
National Center for Atmospheric Research
D. Richter
National Center for Atmospheric Research
J. G. Walega
National Center for Atmospheric Research
R. A. Washenfelder
National Oceanic and Atmospheric Administration
University of Colorado at Boulder
J. A. De Gouw
National Oceanic and Atmospheric Administration
University of Colorado at Boulder
J. Peischl
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
K. C. Aikin
National Oceanic and Atmospheric Administration
University of Colorado at Boulder
S. A. McKeen
National Oceanic and Atmospheric Administration
University of Colorado at Boulder
G. J. Frost
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
F. C. Fehsenfeld
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
S. C. Herndon
Aerodyne Research, Inc.
Atmospheric Chemistry and Physics
1680-7316 (ISSN) 1680-7324 (eISSN)
Vol. 12 7 3273-3288Subject Categories
Meteorology and Atmospheric Sciences
DOI
10.5194/acp-12-3273-2012