AEROSOL ABUNDANCES AND OPTICAL CHARACTERISTICS IN THE PACIFIC BASIN FREE TROPOSPHERE

被引:37
作者
PUESCHEL, RF
LIVINGSTON, JM
FERRY, GV
DEFELICE, TE
机构
[1] SRI INT,MENLO PK,CA 94025
[2] UNIV WISCONSIN,MILWAUKEE,WI 53201
关键词
ATMOSPHERIC AEROSOLS; BACKGROUND CONCENTRATION; OPTICAL PROPERTIES;
D O I
10.1016/1352-2310(94)90253-4
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
During NASA's Global Backscatter Experiment (GLOBE) mission flights in November 1989 and May 1990, a DC-8 research aircraft probed the Pacific Basin free troposphere for about 90 flight hours in each month between +72 and -62 degrees latitude, +130 and -120 degrees longitude, and up to 39,000 feet pressure altitudes. Aerosols were sampled continuously in situ by optical particle counters to measure concentration and particle size, and during 48 10-min intervals during each mission by wire impactors for concentration, size, composition, phase and shape analyses. The optical particle counters cover a particle diameter range between 0.3 and 20 mum; wire impactors extend the range down to 0.03 mum. Results of particle number, size, shape, together with the assumption of a refractive index corresponding to (NH4)2SO4 to account for the prevalence of aerosol sulfur, were utilized in a Mie algorithm to calculate aerosol extinction and backscatter for a range of wavelengths (0.385 < lambda < 10.64 mum). Computations for 22 randomly selected size distributions yield coefficients of extinction E0.525 = (2.03 +/- 1.20) x 10(-4) km-1 and backscatter beta0.525 = (6.45 +/- 3.49) x 10(-6) km-1 sr-1 in the visible, and E10.64 = (8.13 +/- 6.47) x 10(-6) km-1 and beta10.64 = (9.98 +/- 10.69) x 10(-8) km-1 sr-1 in the infra-red, respectively. Large particles (D > 0.3 mum) contribute two-thirds to the total extinction in the visible (lambda = 0.525 mum), and almost 100% in the infra-red (lambda = 10.64 mum). These results have been used to define an IR optical aerosol climatology of the Pacific Basin free troposphere, from which it follows that the infra-red backscatter coefficient at lambda = 9.25 mum wavelength fluctuates between 5.0 x 10(-10) and 2.0 x 10(-7) km-1 sr-1 with a modal value 2.0 x 10(-8) km-1 sr-1.
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收藏
页码:951 / 960
页数:10
相关论文
共 11 条
[1]   CLIMATE FORCING BY ANTHROPOGENIC AEROSOLS [J].
CHARLSON, RJ ;
SCHWARTZ, SE ;
HALES, JM ;
CESS, RD ;
COAKLEY, JA ;
HANSEN, JE ;
HOFMANN, DJ .
SCIENCE, 1992, 255 (5043) :423-430
[2]   OCEANIC PHYTOPLANKTON, ATMOSPHERIC SULFUR, CLOUD ALBEDO AND CLIMATE [J].
CHARLSON, RJ ;
LOVELOCK, JE ;
ANDREAE, MO ;
WARREN, SG .
NATURE, 1987, 326 (6114) :655-661
[3]   LATITUDINAL VARIATIONS OF STRATOSPHERIC AEROSOLS [J].
FARLOW, NH ;
FERRY, GV ;
LEM, HY ;
HAYES, DM .
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 1979, 84 (NC2) :733-743
[4]   GLOBAL OPTICAL CLIMATOLOGY OF THE FREE TROPOSPHERIC AEROSOL FROM 1.0-MU-M SATELLITE OCCULTATION MEASUREMENTS [J].
KENT, GS ;
MCCORMICK, MP ;
SCHAFFNER, SK .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1991, 96 (D3) :5249-5267
[5]  
Matsumoto T., 1987, Journal of Atmospheric and Oceanic Technology, V4, P336, DOI 10.1175/1520-0426(1987)004<0336:ATS>2.0.CO
[6]  
2
[7]  
PUESCHEL RF, 1993, P IRS 92 CURRENT PRO
[8]  
RUSSELL PB, 1993, UNPUB J GEOPHYS RES
[9]   DIMINISHED EFFECTS OF EL-CHICHON ON STRATOSPHERIC AEROSOLS, EARLY 1984 TO LATE 1986 [J].
SNETSINGER, KG ;
PUESCHEL, RF ;
FERRY, GV ;
VERMA, S .
ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS, 1992, 26 (16) :2947-2951
[10]  
WILLIAMS SF, 1990, GLOBAL BACKSCATTER E