Sulphate aerosol size distributions at Mumbai, India, during the INDOEX-FFP (1998)

被引:15
作者
Venkataraman, C [1 ]
Sinha, P [1 ]
Bammi, S [1 ]
机构
[1] Indian Inst Technol, Ctr Environm Sci & Engn, Bombay 400076, Maharashtra, India
关键词
sources; seasonal variation; urban/coastal site; Indian ocean experiment; regional climate;
D O I
10.1016/S1352-2310(00)00440-4
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Sulphate size distributions were measured at the coastal station of Mumbai (formerly Bombay) through 1998, during the Indian ocean experiment (INDOEX) first field phase (FFP), to fill current gaps in size-resolved aerosol chemical composition data. The paper examines meteorological, seasonal and source-contribution effects on sulphate aerosol and discusses potential effects of sulphate on regional climate. Sulphate size-distributions were largely trimodal with a condensation mode (mass median aerodynamic diameter or M MAD 0.6 mum), a droplet mode (M MAD 1.9-2.4 mum) and a coarse mode (MMAD 5 mum) Condensation mode sulphate mass-fractions were highest in winter, consistent with the high meteorological potential for gas-to-particle conversion along with low relative humidity (RH). The droplet mode concentrations and MMADs were larger in the pre-monsoon and winter than in monsoon, implying sulphate predomi nance in larger sized particles within this mode. In these seasons the high RH, and consequently greater aerosol water in the droplet mode, would favour aerosol-phase partitioning and reactions of SO2. Coarse mode sulphate concentrations were lowest in the monsoon, when continental contribution to sulphate was low and washout was efficient. In winter and pre-monsoon, coarse mode sulphate concentrations were somewhat higher, likely from SO2 gas-to-particle conversion. Low daytime sulphate concentrations with a large coarse fraction, along with largely onshore winds, indicated marine aerosol predominance. High nighttime sulphate concentrations and a coincident large fine fraction indicated contributions from anthropogenic/industrial sources or from gas-to-particle conversion. Monthly mean sulphate concentrations increased with increasing SO2 concentrations, RH and easterly wind direction, indicating the importance of gas-to-particle conversion and industrial sources located to the east. Atmospheric chemistry effects on sulphate size distributions in Mumbai, indicated by this data, must be further examined. (C) 2001 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:2647 / 2655
页数:9
相关论文
共 38 条
[1]  
[Anonymous], 1999, CLIMATIC EFFECTS AER
[2]  
Boucher O, 1998, ANN GEOPHYS-ATM HYDR, V16, P346
[3]   PRECIPITATION AND RADIATION MODELING IN A GENERAL-CIRCULATION MODEL - INTRODUCTION OF CLOUD MICROPHYSICAL PROCESSES [J].
BOUCHER, O ;
LETREUT, H ;
BAKER, MB .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1995, 100 (D8) :16395-16414
[4]   General circulation model assessment of the sensitivity of direct climate forcing by anthropogenic sulfate aerosols to aerosol size and chemistry [J].
Boucher, O ;
Anderson, TL .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1995, 100 (D12) :26117-26134
[5]   THE SULFATE-CCN-CLOUD ALBEDO EFFECT - A SENSITIVITY STUDY WITH 2 GENERAL-CIRCULATION MODELS [J].
BOUCHER, O ;
LOHMANN, U .
TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY, 1995, 47 (03) :281-300
[6]   OCEANIC PHYTOPLANKTON, ATMOSPHERIC SULFUR, CLOUD ALBEDO AND CLIMATE [J].
CHARLSON, RJ ;
LOVELOCK, JE ;
ANDREAE, MO ;
WARREN, SG .
NATURE, 1987, 326 (6114) :655-661
[7]   EFFECT OF ENVIRONMENTAL VARIABLES ON COLLECTION OF ATMOSPHERIC SULFATE [J].
COUTANT, RW .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1977, 11 (09) :873-878
[8]  
Hering S. V., 1995, AIR SAMPLING INSTRUM, P279
[9]   ORIGINS OF AEROSOL SULFUR SIZE DISTRIBUTIONS IN THE LOS-ANGELES BASIN [J].
HERING, SV ;
FRIEDLANDER, SK .
ATMOSPHERIC ENVIRONMENT, 1982, 16 (11) :2647-2656
[10]  
Hobbs P.V., 1993, AEROSOL CLOUD INTERA, P33