Measurements of tropospheric nitric acid over the Western United States and Northeastern Pacific Ocean

Technical Report · Mon Jan 01 04:00:00 EST 1990

OSTI ID:6374503

Lebel, P J; Huebert, B J; Schiff, H I; Vay, S A; Vanbramer, S E; Hastie, D R

Over 240 measurements of nitric acid (HNO{sub 3}) were made in the free troposphere as well as in the boundary layer. Marine HNO{sub 3} measurement results were strikingly similar to results from GAMETAG and other past atmospheric field experiments. The marine boundary layer HNO{sub 3} average, 62 parts-per-trillion by volume (pptv), was 1/3 lower than the marine free tropospheric average, 108 pptv, suggesting that the boundary layer is a sink for tropospheric nitric acid, probably by dry deposition. Nitric acid measurements on a nighttime continental flight gave a free tropospheric average of 218 pptv, substantially greater than the daytime continental free tropospheric 5-flight average of 61 pptv. However, the nighttime results may be influenced by highly convective conditions that existed from thunderstorms in the vicinity during that night flight. The continental boundary layer HNO{sub 3} average of 767 pptv is an order of magnitude greater than the free tropospheric average, indicating that the boundary layer is a source of free tropospheric HNO{sub 3}. The distribution of continental boundary layer HNO{sub 3} data, from averages of 123 over rural Nevada and Utah to 1057 pptv in the polluted San Joaquin Valley of California suggest a close tie between boundary layer HNO{sub 3} and anthropogenic activity.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (USA). Langley Research Center
• OSTI ID: 6374503
• Report Number(s): N-90-26399; NASA-TM--103470; NAS--1.15:103470
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AIR POLLUTION
CONVECTION
DEPOSITION
DRYING
EARTH ATMOSPHERE
ENERGY TRANSFER
HEAT TRANSFER
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MASS TRANSFER
MONITORING
NITRIC ACID
PACIFIC OCEAN
POLLUTION
SEAS
SURFACE WATERS
TROPOSPHERE