Authors

Affiliations

1Viet Nam Institute of Meteorology, Hydrology and Climate change

Abstracts

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.

Keywords

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.

References

1. Liu, J., and R. E., Stewart, 2003. Water Vapor Fluxes over the Saskatchewan River Basin. J. Hydrometeor, 4: 944 - 959.

2. Liu, J., R. E, Stewart., and K. K. Szeto, 2004. Moisture Transport and Other Hydrometeorological Features Associated with the Severe 2000/01 Drought over the Western and Central Canadian Prairies. J. Climate.17: 305 - 319.

3. Nguyen, D. N., 2017. 2015/2016 El Niño event and Its impact on Vietnam. Journal of climate change science. 1: 29-36.

4. Nguyen, V.T., Nguyen, T.H., Mai, V. K., Vu, V. T., 2017. The characteristics of atmospherical circulation and status of rainfall deficit in Viet Nam during 2014 - 2016 El Nino event. Journal of climate change science. 4: 2-14.

5. Nguyen, T. H. T., 2004. Calculatingmoisture transport in the atmosphere. The report of scientific workshop 11th in Viet Nam Institute of Meteorology, Hydrology and Environment.

6. Nguyen,T. H., 2014. Research the basic characteristics and impact of ENSO to drought, heavy rainfall at Vietnam and the prediction. Associate Report for the basic mechanism, teletercodeNCCB-DHUD.2011-G/12.

7. Valsala, V. K., and M. Ikeda, 2005. An Extreme drought event in the 2002 summer monsoon rainfall and its mechanism proved with a moisture flux analysis. SOLA. 1: 173- 176, doi:10.2151.

8. Vu, V.T., Nguyen, V.T., Pham, T.T.H., Nguyen, T.H., 2012. Characteristics of moisture transport in Vietnam under El Nino condition. The report of scientific workshop 11th in Viet Nam Institute of Meteorology, Hydrology and Enviroment. Scientifc and Technical Publisher.

9. Vu, V.T., Nguyen, V.T., Nguyen, T.H., Nguyen, V. H., Do, T.N., Nguyen, T.H., Hoang, D.C., 2014. The shortage of rainfall in May during El Nino periods in the Central Highlands and role of moisture transport. Scientific and Technical hydro – MeteorologicalJournal. 644: 1- 4.

10. Vu, V.T., 2016. Characteristics of moisture transport in the ENSO events in Vietnam. Earth sciences dissertation.

11. Vu, V. T., Nguyen, H. T., Nguyen, T. V., Nguyen, H. V., Pham, H. T. T., & Nguyen, L. T., 2016. Effects of ENSO on autumn rainfall in Central Vietnam. Advances in Meteorology.

12. Simonds, I., D. Bi, and P. Hope, 1999. Atmospheric water vapour flux and its association with rainfall over China in summer. J. Clim. 12: 1353-1367.

13. Sminov, V., and G. Moor, 2000. Shortterm and seasonal variability of the atmospheric water vapour transport through the Mackenzie River Basin. J. of Hydromet. 2: 441- 452.

14. Xiaoxia, Z., Y. Ding, and P. Wang, 2010. Moisture transport in the Asian summer monsoon region and its relationship with summer precipitation in China. Acta Meteor. Sinica. 24 (1): 31-42.

15. Zhang, R., and A. Sumi, 2002. Moisture Circulation over East Asia during El Nin˜o Episode in Northern Winter,Spring and Autumn. J. Meteor. Soc. Japan. 80 (2): 213 - 227.

16. Zhou, T. J., and R. C. Yu, 2005. Atmospheric water vapor transport associated with typical anomalous summer rainfall patterns in China. J. Geophys. Res. 110: D08104, doi:10.1029/2004JD005413.