El-Nino Phenomena and 500 hPa Atmospheric Circulation in Northern Hemisphere

In this paper, the teleconnection between sea surface temperatures in the eastern equatorial Pacific and 500 hPa geopotential height fields over the northern hemisphere has been discussed. The teleconnection patterns show that there are a positive correlation zone over the low latitudes and a negative correlation zone over the middle latitudes. The positive correlation region is located over the southwestern part of the Northern Pacific and the negative correlation region over the northern and central parts of Northern Pacific. It is found that there is a “large semicircular belt” which passes through the Northern Pacific, the North Pole, the Eastern America and the Northern Atlantic with positive and negative correlation regions alternatively. It is also shown that the conditions of subtropical high of the NW Pacific and Meiyu (bai-u) of Yangtze River Valley etc. are influenced by El-Nino phenomena