Open AccessImpact of biomass burning on rainwater acidity and composition in Singapore
Author(s) -
Balasubramanian R.,
Victor T.,
Begum R.
Publication year - 1999
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd900247
Subject(s) - haze , particulates , environmental science , precipitation , environmental chemistry , biomass burning , air quality index , biomass (ecology) , atmosphere (unit) , inorganic ions , trace gas , plume , rainwater harvesting , aerosol , atmospheric chemistry , pollutant , atmospheric sciences , chemistry , meteorology , ion , geology , ozone , geography , ecology , oceanography , organic chemistry , biology
The Indonesian forest fires that took place from August through October 1997 released large amounts of gaseous and particulate pollutants into the atmosphere. The particulate emissions produced a plume that was easily visible by satellite and significantly affected regional air quality in Southeast Asia. This prolonged haze episode provided an unprecedented opportunity to examine the effects of biomass burning on regional atmospheric chemistry. We undertook a comprehensive field study to assess the influence of biomass burning impacted air masses on precipitation chemistry in Singapore. Major inorganic and organic ions were determined in 104 rain samples collected using an automated wet‐only sampler from July through December 1997. Mean pH values ranged from 3.79 to 6.20 with a volume‐weighted mean of 4.35. There was a substantially large number of rain events with elevated concentrations of these ions during the biomass burning period. The relatively high concentrations of SO 2− 4 , NO − 3 , and NH + 4 observed during the burning period are attributed to a long residence time of air masses, leading to progressive gas to particle conversion of biomass burning emission components. The decrease in pH of precipitation in response to the increased concentrations of acids is only marginal, which is ascribed to neutralization of acidity by NH 3 and CaCO 3 .