[Correlation of delta18O in precipitation and moisture sources at Yunfu, Western Guangdong Province, China].
Fifty-nine samples of atmospheric precipitation were collected at Yunfu, Western Guangdong province during the period of April 5, 2005 to April 1, 2006 and their oxygen isotopic compositions were analyzed. Results show that delta18O values range from -12.47 per thousand to -0.18 per thousand with an average of -4.91 per thousand; the delta18O values of summer and autumn (from May to September) are relatively lower, ranging from -10.00 per thousand to -5.00 per thousand with an average of -6.30 per thousand; the delta18O values of winter and spring (from October to next April) are relatively higher, ranging from - 3.00 per thousand to - 1.00 per thousand with an average of - 2.20 per thousand. These delta18O values have relatively marked negative correlation with the corresponding temperatures and water vapour pressure and their coefficients are both -0.60; but they have had negative correlation with the precipitation amount, the coefficient is -0.33. Comparing with the monthly delta18O value of Guangzhou atmospheric precipitation, those of Yunfu City is relatively lower, maybe the reason is that Yunfu City is influenced by stronger South-West Asian Monsoon. The results of HYSPLIT back trajectory analysis indicated that the differences of delta18O values are determined by different water vapour sources during the pre-rainy season (from April to June), post-rainy season (from July to September) and non-rainy season (from October to next April), so the delta18O values can be considered as an indicator of denoting their water vapour sources, relatively higher delta18O values denote the water vapour sources are denaturalized tropical hot air mass located in the subtropical sea areas (including the South China Sea), western Pacific Ocean; relatively lower delta18O values indicate denaturalized tropical hot air mass from the India Ocean and Bengal Gulf.
School of Geography Science, South China Normal University, Guangzhou 510631, China. nhzym2@163.com
Yan-Ming
YM
Zheng
Wei
W
Zhong
Xiao-Ying
XY
Peng
Ji-Bin
JB
Xue
Yin-Juan
YJ
Zhao
Qiao-Hong
QH
Ma
Ying
Y
Cai
D000392:Air Movements; D011232:Chemical Precipitation; D002681:China; D004784:Environmental Monitoring; D010103:Oxygen Isotopes / Q000032:analysis*; D011891:Rain / Q000737:chemistry*; D012621:Seasons; D014919:Wind
D010103:Oxygen Isotopes