Summer rain events in south-east Asia: Spatial and temporal variations

Yeung, MC; Lee, SC; Lun, BH; Tanner, PA

HERO ID

102066

Reference Type

Journal Article

Year

2007

HERO ID 102066
In Press No
Year 2007
Title Summer rain events in south-east Asia: Spatial and temporal variations
Authors Yeung, MC; Lee, SC; Lun, BH; Tanner, PA
Journal Atmospheric Research
Volume 86
Issue 3-4
Page Numbers 241-248
Abstract During the summer monsoon period in south-east Asia marine airstreams normally prevail at the south China coast. However, when tropical cyclones approach then polluted airmasses from south-eastern China can impart high ionic concentrations and high acidity to rainwater. This is illustrated by two examples and the small-scale horizontal variations in rainwater composition are minor during these episodes. Since long-term quality-assured studies of the composition of rainwater in south-cast Asia are scarce, the results at three sampling sites in Hong Kong during summer monsoon periods are compared with previous data from the same season. The results for the mid- to end- 1990's show a similar trend to those for the ambient concentrations of sulphate and nitrate in aerosol in Hong Kong, which show flattened trends from 1995 to 1999. A marked increase in acidity is found in the summer monsoon period of 2004 which is attributed to the greater proportion of approaching cyclone weather systems in the dataset, reflecting both the increased local emission sources and the burgeoning economic growth of the Pearl River Delta Region. Comparison of the rainwater composition with that at other south-cast Asian cities during the summer monsoon period shows that it is most acidic in Hong Kong. (c) 2007 Elsevier B.V All rights reserved.
Doi 10.1016/j.atmosres.2006.09.011
Wosid WOS:000251464200005
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword east Asia; bulk deposition; nitrate; sulphate; pH
Is Qa No