Aerosol size distribution, composition, and CO sub 2 backscatter at Mauna Loa Observatory

Journal Article · Wed Mar 20 00:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JD02211· OSTI ID:5469979

Clarke, A D; Porter, J N ^[1]

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1. Univ. of Hawaii, Honolulu (USA)

Continuous measurements of aerosol size distributions were obtained during Jan-Mar and Nov-Dec periods of 1988 at Mauna Loa Observatory, Hawaii. These periods were chosen in order to characterize aerosol physiochemistry during periods representative of low-dust atmospheric conditions and periods associated with appreciable Asian dust transport to that site. Size distributions for particles with diameters between 0.15 and 7.6 {mu}m were accumulated in 256 size bins of a laser optical particle counter for 3-hour intervals during most of the period. The aerosol sample stream was heated to selected temperatures in order to provide size-discriminated measurements of aerosol volatility. Resulting data were used to assess the variability in aerosol concentrations and properties related to aerosol backscatter values at a wavelength of 10.6 {mu}m, {beta}{sub CO{sub 2}}, in the mid-troposphere. Low aerosol concentrations, considered representative of mid-tropospheric air, occurred in downslope flow between midnight and sunrise. Measurements for these time periods suggest that {beta}{sub CO{sub 2}} varied from a low of about 5 {times} 10{sup {minus}12}m{sup {minus}1}sr{sup {minus}1} to a high of 5 {times} 10{sup {minus}8}m{sup {minus}1}sr{sup {minus}1}. Coarse particles with diameters between 1.0 and 5.0 {mu}m account for most of the derived values of {beta}{sub CO{sub 2}} at all but the highest and lowest aerosol mass concentrations. Volatile aerosol appears to dominate aerosol mass during the cleanest periods but was a small fraction of the total during dust events. The authors estimate that minimum values for {beta}{sub CO{sub 2}} at about 8 km should usually fall in the range of 1-3 {times} 10{sup {minus}12}m{sup {minus}1}sr{sup {minus}1} and be dominated by a sulfate aerosol.

• OSTI ID: 5469979
• Journal Information: Journal of Geophysical Research; (United States), Vol. 96:D3; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROSOLS
CHEMICAL COMPOSITION
PARTICLE SIZE
HAWAII
AIR POLLUTION
ASIA
ATMOSPHERIC CHEMISTRY
BACKSCATTERING
CARBON DIOXIDE
DISTRIBUTION
DUSTS
ECOLOGICAL CONCENTRATION
LONG-RANGE TRANSPORT
SULFATES
TROPOSPHERE
VOLATILE MATTER
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMISTRY
COLLOIDS
DEVELOPED COUNTRIES
DISPERSIONS
EARTH ATMOSPHERE
ENVIRONMENTAL TRANSPORT
FEDERAL REGION IX
MASS TRANSFER
MATTER
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
POLLUTION
SCATTERING
SIZE
SOLS
SULFUR COMPOUNDS
USA
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)