Acidic and related constituents in liquid water stratiform clouds

Journal Article · Mon Feb 20 04:00:00 EST 1984 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JD089iD01p01447· OSTI ID:6675010

Daum, P H; Schwartz, S E; Newman, L

Composition of cloud liquid water and interstitial air is reported for aircraft measurements near Charleston, South Carolina, in February 1982. Cloud water was collected by means of a slotted-rod impactor. Cloud-free interstitial air was obtained by a centrifugal separator. Principal ionic species in cloudwater were H/sup +/, SO/sub 4//sup -/, NO/sub 3//sup -/, and NH/sub 4//sup +/. The relative acidity of cloudwater, as measured by the ratio of H/sup +/ to NH/sub 4//sup +/, was much greater than that of the interstitial aerosol or of clear-air aerosol samples. Gaseous O/sub 3/, NO/sub 3/ (i.e., NO+NO/sub 2/), and SO/sub 2/ were present in interstitial air within clouds, whereas HNO/sub 3/ an NH/sub 3/ were below limit of detection (0.4 ppb for both species). Comparision of relative acidity of cloudwater samples with that of clear-air samples suggests that clear-air aerosol and HNO/sub 3/ are incapable of providing the levels of acidity observed in cloudwater. Such acidity would be consistent with in-cloud conversion of prevailing concentrations of SO/sub 2/ or SO/sub 2/+NO/sub 4/ to aqueous strong acid, although other hypotheses cannot be excluded. Comparison of absolute concentrations of cloudwater constituents to concentration in clear-air measurements gives no indication of accumulation of sulfur and nitrogen species by clouds.

• Research Organization: Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory
• OSTI ID: 6675010
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 89:D1; ISSN JGREA
• Country of Publication: United States
• Language: English

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500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AMMONIA
CHALCOGENIDES
CHEMICAL COMPOSITION
CLOUDS
DROPLETS
FEDERAL REGION IV
HYDRIDES
HYDROGEN COMPOUNDS
NITRATES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
OZONE
PARTICLES
PH VALUE
RAIN WATER
SOUTH CAROLINA
SULFATES
SULFUR COMPOUNDS
USA
WATER