The culprit caused an unusually hot and cold weather phenomenon

The Merchant Specialist, chairman of the World Meteorological Organization's Climate and Disaster Committee (WMO), explains the extreme weather phenomenon in cold weather in 2015 and the 2016 forecast.

According to Xinhua, winter this year, many areas in China appear short and deep cold waves. In North America and Europe also appeared local cold, Japan this weekend also expected a deep cold wave. However, at the World Conference on Global Climate Change held in Paris in early December, all reports stated that 2015 is the hottest year in modern history.

There are two causes of this cold and hot phenomenon, the first cause of polar cyclones (polar vortex) and the jet stream.

Reason

Polar cyclones are large, very cold gas masses present at the two poles (Arctic and Antarctic) , located above the troposphere and in the middle of the stratosphere. According to Mr. Tu, in the past, cold air masses in the two poles operated relatively stable but since the earth began to heat up, these gases have become more active. Therefore, the North Pole appears small cold air masses spread southward, causing local deep cold.

Picture 1 of The culprit caused an unusually hot and cold weather phenomenon
The Songhua River face in Jilin City closed into ice.(Photo: Rex).

The beam is a high-speed narrow air stream moving west to east around the Earth , located at the top of the troposphere and between the stratosphere. Beam currents are affected by the temperature difference between the Arctic Circle and the middle latitude region (latitude 30-60). The greater the difference in temperature, the stronger the speed of movement of the beam, forming a straight line. In contrast, the low temperature difference causes its speed to slow down, moving in a meandering shape. If the Arctic temperature rises, the temperature difference with the mid-latitude region will decrease, causing oscillation of the larger beam path, resulting in extreme extreme weather fluctuations of the amplitude. .

According to Thuong Tu, the unusual variation of polar currents and tornadoes is the reason that this year's seasonal weather appears extreme changes, at extremely hot, extremely cold.

The second reason is that the El Nino phenomenon increases the phenomenon of extreme weather.

Influence of El Nino and 2016 forecast

El Nino is the cause of sea temperature in the central and eastern Pacific region to warm abnormally, causing extreme weather around the world such as storms and floods last year in North and South America, or unusual heat in Asia in May.

Last Christmas in the east of the United States appeared "warm winter" , temperatures in some areas even reached more than 20 degrees C, cherry blossoms bloomed before the season. In the south, southwest and central parts of the United States, rainstorms, tornadoes and floods again appeared. On December 25, 2015 in Montreal, Canada, the highest temperature reached 16 degrees Celsius, but only three days later dropped deeply to -10 degrees C.

"The temperature change caused by abnormal cold air does not represent the year-round weather. The average temperature in 2015 in China has increased by almost 1 degree Celsius compared to the average. global warming and warm winters will continue to happen in China, " CRI quoted Zhu Dingzhen, Chinese meteorological expert.

Picture 2 of The culprit caused an unusually hot and cold weather phenomenon
The impact of El Nino to the world in 2015. (Graphics: Open Snow).

According to the British Meteorological Agency, taking the average temperature of the Earth from 1960 to 1990, the average temperature in 2014 increased 0.57 degrees Celsius, in 2015 increased by 0.75 degrees Celsius, expected to increase in 2016. 0.84 degrees C.

Mr. Thuong Tu judged that El Nino will also cause more extreme weather events in the coming time. 2016 is expected to be hotter this year, and the world will receive a new record heat wave.