Scavenging of urban pollutants by thunderstorm rainfall: Numerical experimentation

Journal Article · Mon May 01 04:00:00 EDT 1978 · J. Appl. Meteorol.; (United States)

DOI:https://doi.org/10.1175/1520-0450(1978)017<0699:SOUPBT>2.0.CO;2· OSTI ID:6543909

Hane, C E

Rainfall collected for the squall line case of 21 August 1972 in the St. Louis area has been analyzed for certain pollutants known to be present in urban air. To aid in the interpretation of these measurements a two-dimensional time-dependent squall line model is utilized to approximate the internal air flow and rainwater distribution within the storm. At a particular time when a typical mature circulation is present, a steady state is assumed and a pollutant plume with dimensions and concentrations characteristic of the St. Louis urban plume is allowed to interact with the model thunderstorm circulation. The study focuses upon the effect of internal storm motion upon precipitation scavenging and treats microphysical processes in a relatively simple manner.Two extreme situations are considered :1) the pollutant does not interact with the water substance in the storm, but is merely redistributed by the storm circulation; and 2) all pollutant enters into cloudwater immediately upon entering the cloud boundary. In the second case, scavenging of pollutants by precipitation is calculated along with the deposition of pollutant on the ground in rainfall. The deposited amounts are compared with the limited number of measurements from the same storm. The trend and order of magnitude of deposition arrived at in the model compare favorably with the observations. Areas where additional observations are greatly needed are specified and desirable directions for model development are discussed.

• Research Organization: Atmospheric Sciences Department, Battelle-Northwest Laboratories, Richland, Wash. 99352
• OSTI ID: 6543909
• Journal Information: J. Appl. Meteorol.; (United States), Journal Name: J. Appl. Meteorol.; (United States) Vol. 17:5; ISSN JAMOA
• Country of Publication: United States
• Language: English

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500100* -- Environment
Atmospheric-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
ATMOSPHERIC PRECIPITATIONS
DISASTERS
FLUIDS
GASES
MIDWEST REGION
MISSOURI
NORTH AMERICA
PLUMES
POLLUTION
PRECIPITATION SCAVENGING
RAIN
SEPARATION PROCESSES
STORMS
TWO-DIMENSIONAL CALCULATIONS
USA
VAPORS
WASHOUT
WATER VAPOR