WHAT CAUSES HEAT WAVE FROM JUNE 1st TO JUNE 6th 2017 IN THE NORTH VIET NAM

Abstract

In this article, the FNL data of the National Oceanic and Atmospheric Administration, US (NOAA) was used in analysing the reasons of the heat wave from 1 june to 6 june 2017 in the North Viet Nam. According to meteorological experts, this heat wave causeed new temperature recorded during over last 40 years and the higher than the previous record of 1.5^oC in Hanoi [7-8]. The research results showed that this heat wave is caused by topographic effects for weather patterns in the medium to large scale. The local low pressure occurred at the 850 hPa in the North, the activity of this low pressure caused the advantage condition for hot-dry west wind from Myanmar moving into Viet Nam. Because of Interacting with high terrain, this west wind caused the foehn effect; especially caused the very high temperature over nothern delta region. At the 200 hPa, the sub-tropical high pressure dominated over the North Viet Nam. Because of activity of this high pressure, which caused the advantage condition for increasing the direct solar radiation to heat up the surface and preventing the development of hot air masses in low elevation (at the 850 hPa). Over 6 june 2017, this high pressure moved completely out of the East Sea and the heat wave was ended in the North Viet Nam.