摘要:

We report data for the Enewetak site of the SEAREX program from the rainy season in 1979. The concentrations ofn‐alkanes,n‐alkanols, sterols,n‐alkanoic acids and their salts, and total organic compounds in rain are reported, as well as the apparent gaseous hydrocarbon concentrations. These data and information on the particulate forms are analyzed in conjunction with ancillary chemical and meteorological data to draw inferences about sources, fluxes, and chemical speciations. While the higher molecular weight lipid biomarker components are exclusively terrestrial, the organic carbon in rain may be derived from atmospheric transformations of terrestrial carbon. Distinctively marine components are nearly absent. Comparison of the scavenging ratios of the organic components in rain vs. those for clays reveals that the alkanoic acids and the higher molecular weight alkanols behave as essentially particulate materials, whereas lower alkanols and most hydrocarbons show much higher scavenging ratios, probably due to the involvement of a gaseous phase or sampling artifact. Vaporization in the atmosphere and scavenging of a gas phase would lead to higher scavenging ratios; vaporization during sampling would give low aerosol concentrations and high gas‐phase concentrations, leading to high scavenging ratios. The major fluxes at Enewetak result from rain rather than dry deposition, and extrapolating the measured values to meaningful annual averages requires adjustment for seasonally varying source intensity and rain dynamics. Aerosol data for other seasons and other substances are used to correct for source‐strength intensity variations, and a210Pb/organic compound correlation is established and extrapolated to adjust for rainfall volume effects. These corrections, assumed independent and applied together, yield inferred fluxes 2.5–9 times larger than the fluxes calculated for mean concentrations. The inferred fluxes to the ocean, while small compared to primary production, are large enough to have potential impacts in the cycle of dissolved organic carbon and the sedimentary geochemistry of refractory lipid

ISSN:0148-0227    

DOI:10.1029/JD090iD01p02409

年代:1985

数据来源: WILEY

摘要:

An aircraft measurement program was undertaken in the savanna regions of central South America in the dry season of 1980 to investigate the atmospheric effects of large‐scale biomass burning. The smoke from the fires was found to be largely confined within an approximately 3‐km‐deep boundary layer capped by a subsidence inversion or a stable layer. This condition typically persists for week‐long periods as a result of the synoptic subsidence occurring during the dry season. Photochemical production of ozone occurred in the polluted layer over the entire Cerrado region of central Brazil. The factors controlling the concentration of this ozone are examined, and an estimate of the amount of ozone produced is r

ISSN:0148-0227    

DOI:10.1029/JD090iD01p02425

年代:1985

数据来源: WILEY

摘要:

Three trace NOXspecies—HONO, N03.and N2O5—may play important roles in urban smog formation. Alternative mechanisms for these species have recently been proposed. This report presents a brief analysis of simulation results indicating that the traditional chemistry for these species can still explain the results of some recent observational stud

ISSN:0148-0227    

DOI:10.1029/JD090iD01p02430

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JD090iD01p02433

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JD090iD01p02434

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JD090iD01p02435

年代:1985

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JD090iD01p02438

年代:1985

数据来源: WILEY