NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Large-Scale Distributions of Tropospheric Nitric, Formic, and Acetic acids Over the Westerm Pacific Basin During WintertimeWe report here measurements of the acidic gases nitric (HNO3), formic (HCOOH), and acetic (CH3COOH) over the western Pacific basin during the February-March 1994 Pacific Exploratory Mission-West (PEM-West B). These data were obtained aboard the NASA DC-8 research aircraft as it flew missions in the altitude range of 0.3 - 12.5 km over equatorial regions near Guam and then further westward encompassing the entire Pacific Rim arc. Aged marine air over the equatorial Pacific generally exhibited mixing ratios of acidic gases less than 100 parts per trillion by volume (pptv). Near the Asian continent, discrete plumes encountered below 6 km altitude contained up to 8 parts per billion by volume (ppbv) HNO3 and 10 ppbv HCOOH and CH3COOH. Overall there was a general correlation between mixing ratios of acidic gases with those of CO, C2H2, and C2Cl4, indicative of emissions from combustion and industrial sources. The latitudinal distributions of HNO3 and CO showed that the largest mixing ratios were centered around 15 deg N, while HCOOH, CH3COOH, and C2Cl4 peaked at 25 deg N. The mixing ratios of HCOOH and CH3COOH were highly correlated (r(sup 2) = 0.87) below 6 km altitude, with a slope (0.89) characteristic of the nongrowing season at midlatitudes in the northern hemisphere. Above 6 km altitude, HCOOH and CH3COOH were marginally correlated (r(sup 2) = 0.50), and plumes well defined by CO, C2H2, and C2Cl4 were depleted in acidic gases, most likely due to scavenging during vertical transport of air masses through convective cloud systems over the Asian continent. In stratospheric air masses, HNO, mixing ratios were several parts per billion by volume (ppbv), yielding relationships with 03 and N2O consistent with those previously reported for NO(y).
Document ID
19980019625
Acquisition Source
Langley Research Center
Document Type
Contractor Report (CR)
External Source(s)
Authors
Talbot, R. W.
(New Hampshire Univ. Durham, NH United States)
Dibb, J. E.
(New Hampshire Univ. Durham, NH United States)
Lefer, B. L.
(New Hampshire Univ. Durham, NH United States)
Scheuer, E. M.
(New Hampshire Univ. Durham, NH United States)
Bradshaw, J. D.
(Georgia Inst. of Tech. Atlanta, GA United States)
Sandholm, S. T.
(Georgia Inst. of Tech. Atlanta, GA United States)
Smyth, S.
(California Univ. Irvine, CA United States)
Blake, D. R.
(California Univ. Irvine, CA United States)
Blake, N. J.
(California Univ. Irvine, CA United States)
Sachse, G. W.
(NASA Langley Research Center Hampton, VA United States)
Collins, J. E.
(NASA Langley Research Center Hampton, VA United States)
Gregory, G. L.
(NASA Langley Research Center Hampton, VA United States)
Date Acquired
August 17, 2013
Publication Date
December 20, 1997
Publication Information
Publication: Journal of Geophysical Research
Publisher: American Geophysical Union
Volume: 102
Issue: D23
ISSN: 0148-0227
Subject Category
Environment Pollution
Report/Patent Number
NAS 1.26:207353
Paper-96JD02975
NASA/CR-97-207353
Funding Number(s)
CONTRACT_GRANT: NAG1-1233
Distribution Limits
Public
Copyright
Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available