Why is it snowing so heavily in Shanghai this year?

"The national average temperature has reached a record high." "Rainfall intensity in some areas has set a new record." "The death toll caused by lightning disaster is the highest in history."

On August 8, Song Lianchun, spokesperson of China Meteorological Bureau and director of the Department of Forecasting and Disaster Reduction, said at the "online news conference" that since the beginning of this year, China's climate has been abnormal, extreme weather has occurred frequently, many meteorological records have been broken, and meteorological disasters have been characterized by multiple occurrences, wide range and high intensity.

phenomenon

Count the "most" cases of abnormal weather

10-July, the national average temperature was 65438 0.4 degrees higher than the same period of last year, and the average temperatures in Shanghai, Jiangsu, Zhejiang, Jiangxi, Hunan, Xinjiang and other provinces and cities all reached record highs.

Strong thunderstorms occur frequently. On July 17, the 24-hour precipitation in Chongqing reached 267mm, which was the highest since the meteorological record in Chongqing 1 15. On July 18, the maximum precipitation in Jinan 1 hour reached 15 1mm, breaking the historical extreme.

Strong convective weather such as thunder and lightning, strong wind and hail has many points, wide area and high frequency, and the death toll caused by thunder and lightning is the highest in the past years.

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Counting the "worst" climate this year, a set of figures just reflects the "evil" of this year's climate-

As of July 24th, 30.37 million people in Anhui, Jiangsu and Henan provinces were affected by the Huaihe River flood, and1130,000 people were resettled urgently, resulting in direct economic losses of171900,000 yuan.

The drought-affected area of crop farmland in Hunan, Jiangxi, Zhejiang and Fujian provinces is 6.5438+0.067 million hectares, with 6.5438+0.93 million people and 654.38+0.0 1.0000 large livestock. The drought in Jiangxi and Hunan provinces is serious, with 210.3 million hectares and 207,000 hectares of late rice respectively.

Dr Gao Hui from the Climate Prediction Office of the National Climate Center said: "The abnormal weather in China this year is mainly manifested in two points. One is strong convective weather, such as lightning and extreme rainstorm; First, high temperature and drought. "

-The reason is-

Why does the high temperature area in China expand?

With the temperature rising figures released by the meteorological department, a new list of "three stoves" appeared among the people: Fuzhou, Guangzhou and Hangzhou. No matter how authoritative the ranking is, it is an indisputable fact that there is a heat wave in areas where there is no high temperature in the traditional sense this summer.

In this regard, Gao Hui believes that there are two main reasons: First, the background of global warming. Under the background of global warming, the frequency and intensity of some extreme weather events, especially extreme rainstorm, high temperature and drought, have increased; Second, the previous high temperature, snow cover and recent abnormal atmospheric circulation. From August last year to May 438+10 this year, a weak El Ni? o event occurred in the equatorial eastern Pacific, and there was a lot of snowfall on the Qinghai-Tibet Plateau in winter of 2006 and 2007. Recently, the subtropical high is on the south and the summer monsoon is weak, which makes this year's precipitation tilt to the south of the Yellow River. At the same time, the emergence of new stoves is closely related to the stable control of South China by subtropical high, which leads to the continuous high temperature in these areas.

Why are local floods frequent all over the country?

Jiao, director of the National Meteorological Center and director of the Central Meteorological Observatory, believes that this year's main flood season is a year of heavy rains and floods, especially in the Jianghuai-Jiang Yan area and the eastern part of southwest China, which caused local floods. At the same time, China is one of the countries most seriously affected by monsoon, and it is easy to produce heavy precipitation in summer. However, the summer rainfall is relatively concentrated in a certain area or basin for a certain period of time, which determines that the areas affected by the summer rain belt in China are prone to local floods and basin floods. Since June, the main rainfall belts in China have experienced the change process of "South China begins-North Lift-South Fall-North Lift".

Why are the floods and droughts in Chongqing so clear?

Last year, there was a severe drought in Chongqing, and this year, it was hit by 1 10. Experts believe that the main reason is that from February 65438+ in 2005 to February 2006, the snow-covered area on the Qinghai-Tibet Plateau was nearly 10% less than normal, and the number of snow-covered days was also 10-30 days less than normal. The abnormal situation of snow makes the surface temperature over the plateau 2-4 degrees Celsius higher than normal in winter. However, due to the strong summer monsoon in East Asia and the northerly position of the wind and rain belt, the precipitation in Chongqing is relatively small. This year, the situation is just the opposite, resulting in more precipitation in Chongqing.

-Forecast-

Abnormal weather will not disappear in a short time.

As for the future high temperature trend, meteorologists said that although it has arrived in beginning of autumn, the power of the "autumn tiger" cannot be underestimated, the disastrous weather will not disappear in a short time, and the droughts in Jiangnan, Northeast China and Northeast China may continue or develop. "During high temperatures, some areas are prone to disastrous weather, such as thunderstorms; After the high temperature, tropical cyclones may reappear, bringing strong winds and heavy rains. " The National Climate Center predicts that in the future, floods may occur in parts of western Huanghuai and southeastern Northwest China. Strong convective weather such as thunderstorms, hail, lightning strikes and tornadoes may occur frequently, and relevant departments need to further do relevant preventive work.

When will the typhoon cool down the "high fever" south China Jiangnan? The National Climate Center predicts that there will be 4-6 typhoons or tropical storms in the northwest Pacific and South China Sea in August, and 2-3 may land in China's coastal areas. From 9th to12nd, affected by tropical storm No.7 "Pabu" and No.8 "Butterfly" this year, Leizhou Peninsula and Shandong Peninsula in Guangdong Province were hit by heavy rain, and some areas suffered severe floods. According to the latest statistics of the National Defense General on June 5438+02, Guangdong Province1165,000 people were affected, more than 3,600 houses collapsed, and the direct economic loss was13.4 billion yuan. In Shandong province, 2510.4 million people were affected, and 357 houses collapsed, resulting in a direct economic loss of 272 million yuan.

People must first adapt to climate change.

Relevant experts pointed out that in order to minimize disaster losses and ensure the safety of people's lives and property, it is necessary to put the prevention of extreme weather and climate disasters in an important position to deal with climate change. However, there is a strong uncertainty about climate change, and the current understanding of climate is only the tip of the iceberg. Therefore, the first thing people should do is to adapt to climate change, that is, on the basis of understanding climate change, understand its impact on ecology, environment, economy and human health, and take corresponding countermeasures. In the process of dealing with climate change, we need not only the efforts of scientists and government departments, but also the collective efforts of the public. Reducing greenhouse gas emissions, planting trees, using advanced energy-saving technologies, turning off lights and driving small-displacement cars are all things we can do to mitigate the impact of climate change.

-opinions-

Song Lianchun (spokesperson of China Meteorological Bureau, director of the Department of Prediction and Disaster Reduction): There are many extreme weather and climate phenomena related to global warming this year. Because according to the fourth scientific assessment report of IPCC, with global warming, the frequency of extreme weather and climate will increase. This is an indisputable fact. It should be said that our country is also a victim of global warming. Global warming leads to abnormal atmospheric circulation, which leads to some abnormal changes in our meteorological elements and some meteorological disasters. We can predict that extreme weather and climate events in China will become more and more frequent in the future.

Gao Hui (Ph.D., Climate Prediction Office, National Climate Center): August is an active month for typhoons, and the activities of tropical storms or typhoons have obviously increased. The eastern coast where typhoons are easy to land should strengthen its defense against strong typhoons; In view of the possible floods in the western part of Huanghuai and parts of the southeastern part of the northwest, strengthen the defense work against the storms, floods, mudslides and landslides caused by them; In the period of frequent strong convective weather such as thunderstorms, hailstorms, lightning strikes and tornadoes, we should pay close attention to weather changes and take effective measures to reduce casualties and property losses; In August, the temperature in southeastern Jiangnan and northeastern South China was higher than 1 Celsius. Relevant departments and the public should take effective measures in time to do a good job in heatstroke prevention and cooling. Special attention should also be paid to the high fire risk rating of forests and grasslands in central Jiangnan and southern Daxinganling.

-Related links

In recent years, China's meteorological disaster monitoring and early warning capabilities have been significantly improved. At present, China has built more than 1 10 new generation weather radars and more than 15000 automatic weather stations, and we also have Fengyun series meteorological satellites. According to these modern detection methods, the monitoring ability of meteorological disasters is improved, and the prediction level based on numerical prediction model is also improved. The means of meteorological services have been improved, the scope of services has been continuously broadened, and the public coverage of meteorological information has been significantly improved.