Viet Nam Institute of Meteorology, Hydrology and Climate change

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In this article, the rainfall deficiency in October, November over the Central Vietnam during the 1997 - 1998 El Nino event are investigated based on large-scale moisture transport circulation, wind at 10m and 850hPa levels and sea-level pressure.The results show that there were 9 months in total of 12 months from May1997 to April1998 of this El Nino event observed the rainfall deficiency over some climatic regions of Viet Nam. In which, the most significant deficiency occurred in October, November 1997 in the Central Vietnam in a range of 100 - 150 mm, especially the deficiency reached up to 200 mm at some heavy rainfall centers such as Ky Anh, Hue, Tam Ky, Tra My, Ba To. This deficiency seems to be caused by a weakening of the North East monsoon circulation in comparison to the long-term mean, which leads to formation of an anomalous anticyclonic vortex over the East Sea. The appearance of anticyclonic vortex causes a decrease in moisture transport that suppling to rainfall in the Central Viet Nam.  In addition, there is only a main source of moisture from East Sea that favors rainfall formation over Central Viet Nam is lower than climatology.


Cite this paper

Nguyen Van Thang, Vu Van Thang (2018), An Investigation of Rainfall Deficiency in October and November in the Central Vietnam During the 1997 - 1998 El Nino Event. Vietnam Journal of Hydrometeorology, 01, 30-34.


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