Is the cold winter coming? The most extensive cooling, rain and snow will begin next week!
In the next ten days, the middle and lower reaches of the Yangtze River will be affected by strong cold air in the later stage
It is expected that the weather in the middle and lower reaches of the Yangtze River (November 17-26) will be cloudy and rainless. The cumulative precipitation in the eastern part of Guizhou, Chongqing, Jianghuai, South China and South China will be 15 to 40 mm, with 50 to 80 mm in some areas and more than 100 mm in some areas of South China. In addition, the cumulative precipitation in the Yili River Valley of Xinjiang, the eastern part of northwest China, North China, Huang-Huai Valley and most of northeast China ranges from 5 to 15 mm, and in the southeastern part of northwest China, the Huang-Huai district reaches 20 to 40 mm. The rainfall in most of the above-mentioned areas is 3 ~ 70% more than that in the same period of the year, and some areas are 1 ~ 2 times more.
Before The 20th, the cold air was moving to the north. Except for northern Xinjiang, northeastern Inner Mongolia, and the north-central northeast, the average temperature in most other parts of the country was 2 ~ 4℃ higher than that of the normal period. From May 20 to 24, strong cold air will affect China, and the central and eastern parts of the country will see a wide range of rain, snow and strong winds to cool down, with temperatures in most areas turning from high to low.
Major weather processes:
From March 17 to 20, the cold air will affect the north, with temperatures in northern Xinjiang, eastern northwest, North China, northeast China and The Huang-Huaihe River dropping by 4 to 8 ° C, and temperatures in central and eastern Inner Mongolia and southern northeast China dropping by more than 10 ° C. These areas are accompanied by force 4 to 6 northerly winds. Light rain will appear in the eastern part of northwest China, North China, Huanghuai, Jianghuai and other places, with moderate rain in the eastern part of Huanghuai and parts of Jianghuai. Inner Mongolia, most of the northeast will appear small to moderate snow, local large to blizzard.
From May 20 to 24, the central and eastern regions will see a wide range of rain, snow and strong winds to cool down due to strong cold air. The middle and lower reaches of the Yangtze River and the areas to the north will have 4 ~ 6 northerly winds; The temperature in the central and eastern parts of China decreased by 6 ~ 10℃, and the local temperature dropped by more than 12℃. The southeast of northwest China, central and southern North China, Huanghuai, northwest Jianghan and other places will successively appear rain to sleet or snow, south of the South of the Yangtze River, South China will have moderate to heavy rain, south China part of the rainstorm.
This winter has been exceptionally cold. Experts predict China will have a "cold winter" this winter
The source of climate change is often far away. According to a variety of monitoring conditions, meteorological experts have judged that this winter may be a cold winter in China, the root cause is far away in the Arctic ice melt changes and the equatorial Middle East Pacific "La Nina" event.
1 Experts predict this winter may be a cold winter in China
"Arctic sea ice is an important part of the climate system, influencing changes in atmospheric circulation through albedo feedback mechanisms." The melting of arctic sea ice affects China's climate change, said Sui Cuijuan, head of the climate prediction group at the Marine Climate Prediction Office of the National Marine Environment Prediction Center. According to the current arctic ice melting situation, the winter of 2016/2017 is expected to be a cold winter in China.
After the rapid melting of arctic sea ice, the albedo decreases and more energy is stored in the ocean. On the one hand, the melting will be accelerated; on the other hand, more energy will be transferred from the ocean to the atmosphere, changing the air pressure difference between the Arctic region and the mid-latitude region and bringing cold air from the Arctic region to the mid-latitude region, Sui said. The effect of this rapid melting of Arctic sea ice on temperatures is known as the "warm Arctic - cold continent".
Lei Ruibo, an expert in sea ice research at the China Polar Research Center for many years, said that the decrease of arctic sea ice is closely related to China's winter temperature and precipitation. The decrease of arctic sea ice is mainly caused by global warming. For China, it leads to the increase of extreme cold temperatures and the occurrence of cold winters.
On the other hand, SST in the equatorial Middle East and Pacific entered La Nina conditions in August, following a strong El Nino event. Monitoring shows that la Nina state is expected to continue to winter, winter temperature in China has a greater impact.
La Nina is a phenomenon that the ocean surface temperature in the equatorial Middle East and Pacific Ocean is unusually cold. To some extent, la Nina can be called an anti-El Nino phenomenon. The SST anomaly causes the anomaly of atmospheric circulation and affects the global climate. La Nina conditions are currently in place across the equatorial Middle East Pacific Ocean, with a weak to moderate La Nina event expected in December. There is a La Nina state or La Nina event, China's winter is prone to a cold situation.
For China, La Nina has a significant impact on the south, especially the middle and lower reaches of the Yangtze River, said Zhou Bing, a senior engineer and chief expert at the Climate Monitoring Office of the National Climate Center. Comparatively speaking, the degree of north China is more obvious.
Globally, "a combination of 14 La Nina events in history shows that after la Nina events, the probability of colder winters is more than 70 per cent, with relatively colder winters generally occurring." Said zhou bing has done.
Ding Yihui, an academician of the Chinese Academy of Engineering, said that a colder winter is likely to be the main theme this year, and the latter winter is likely to be colder than the former. Zheng Fei, a researcher with the Institute of Atmospheric Physics under the Chinese Academy of Sciences, said that in general, cold air activity is relatively obvious in northern China during la Nina years.
2 Ice melting in a key Arctic sea area could bring a cold winter to China
The variation of arctic sea ice is reflected in the variation of sea ice extent, sea ice thickness and ice age. Monitoring shows that the thickness of arctic sea ice is decreasing sharply, and the ice is getting younger and thinner in the spring.
Li Chunhua, a researcher with the Polar Environment Research and Forecast Office of the National Marine Environment Forecast Center, said that the minimum arctic sea ice extent in the summer of 2012 reached the lowest ever recorded since satellite observation records began, and the minimum arctic sea ice extent in the summer of 2016 was the second lowest ever.
Experts believe that changes in the melting of ice in key arctic sea areas could lead to cold winters in China. Meanwhile, more melting sea ice in the Arctic does not necessarily bring cold winters to our country.
Sui said that both diagnostic analysis and model results show that the Kara and Barents Seas of the Arctic Ocean are key sea areas, and if there is more ice melting in autumn and winter, the temperature in mid-latitude areas of Eurasia or East Asia in winter will be lower than usual. According to the current situation that the sea ice in the Kara Sea and the Barents Sea basically does not increase in October, it is expected that the sea ice extent in this region will be significantly lower in autumn and winter this year than usual, so it is estimated that the winter of 2016/2017 May be a cold winter in China.
"However, it is not the melting of arctic sea ice that brings cold winters to Eurasia. This is mainly related to the melting area." Sui said that the numerical tests show that the most significant ice melting occurs in the Barents sea-Kara Sea in the Atlantic ocean. If the Chukchi and Beaufort seas in the Pacific Ocean melt, there will be a weak cooling effect, which will affect the latitude further south.
As for the link between arctic ice melting and mid-latitude cooling, Sui said the cooling effect would not be significant if both regions had a particularly high amount of sea ice melting. This partly explains why it has not been a cold winter every year in recent years, although the Arctic sea ice extent has been less than it used to be.
3 Under the background of La Nina event, cold winter is a high probability event
According to the melting of ice in the key arctic region, it is predicted that China will have a cold winter this winter. La Nina events from the south also show that this winter is a cold winter event with high probability.
Wang Yongguang, chief expert of the National Climate Center, said la Nina causes about 70 percent of winter temperatures in China to be colder, with more cold air activity.
When La Nina occurs, the anomalous atmospheric cyclone circulation and the north wind in the western Pacific are likely to occur, the east Asian trough is strengthened, the western Pacific subtropical high is weakened, the meridional circulation in the middle and high latitudes in East Asia is obvious, the winter wind is stronger, and China's offshore is prone to cold air waves and cold water freezing damage, Sui said.
Weather experts warned that the cold weather will increase the consumption of energy such as coal, electricity, oil and gas, transportation and livestock farming in the north will also be affected, and should be prepared.
How does agriculture cope with freezing rain and snow to ensure winter wheat safety over the winter
To strengthen the investigation of winter wheat seedling, moisture content, disease and cordyceps sinensis, to guide farmers to conduct classified management, scientifically regulate and control fertilizer and water, and promote the transformation and upgrading of seedling situation. We will further refine and implement the technical plan for drought and frost resistance, pay close attention to the changes of weather and soil moisture, organize farmers to clear the gully moisture in time, ensure the unimpeded gully system, and improve the ability of drainage and moisture reduction as well as drought and cold resistance. We will strengthen the monitoring and forecasting of wheat stripe rust and other pests and the market supervision of pesticides. We will adhere to the strategy of "finding one spot and controlling one patch" to minimize the overwintering base and reduce the pressure of spring prevention and control. It is an effective measure to spread 300 to 400 kilograms of wheat bran, broken straw or other plant waste in each mu of wheat row in dry land, which can not only keep soil moisture but also prevent from freezing, but also can improve the soil and fertilize the soil after the mulch decays. For upland wheat, along the wheat box ditch spread a layer of manure, also known as "warm dung", can avoid wind moisture, increase temperature antifreeze, and for the wheat seedlings green growth supplement nutrients. The thickness that covers excrement with 3, 4 centimeters advisable.
Rapeseed: heavy in anti - freeze to remove stains
Taking anti-freezing and desoiling as the key point in the field management of rapeseed in south China at present, desiccating, draining, dehumidifying and chemical control were adopted to alleviate the effects of freezing injury. Timely fertilizer application promotes seedling conversion. Take effective measures such as covering and loosening soil to keep heat and prevent freezing. The occurrence of early moss and early flower can be delayed by deep tillage and damage of some roots in the plots with signs of early moss and early flower. The rapeseed with early mosses and early flowers can be selected after the Spring Festival when the weather is sunny and the temperature is high to pick mosses, and apply quick nitrogen fertilizer in time to promote the plant to restore vitality and reduce the loss of freezing damage.
Open vegetables: Clear the ditch to remove stains
The key management is to prevent freezing and keep warm, dredge box ditch, edge ditch, waist ditch to remove water, enhance box air permeability, improve the ground temperature, the area where conditions can be taken to cover cultivation. Strengthen vegetable mulch insulation management in large and small sheds. Can be taken in the greenhouse buckle small arch shed, covered with film at night; Or cover straw curtain on the film method, heat preservation dehumidification. Apron is made of plastic film at the bottom of the shed to reduce cold air invasion at the bottom; Plug the gap, as far as possible to reduce gap heat; In the north of the greenhouse with crop straw pile into a wind barrier, wind and cold.
Citrus: To protect the tree body temperature
One is canopy coverage. Cover the plant with straw and agricultural film to protect the temperature of the tree. The second is to cover the rhizome with soil 10-15 cm thick. Young trees can build triangular supports and cover them with straw. The third is smoke heating. 4 to 6 heaps per mu; Fourth, spraying steam inhibitor and heat preservation agent. Before the advent of low temperature, spray antievaporating and heat preservation agent on the citrus canopy to reduce heat loss. Five is the trunk coated white or bandaged, white-coated agent is generally prepared according to the proportion of 10 kg of quick lime, 1 kg of sulfur powder, 0.2 kg of salt, 30 to 40 kg of water, in sunny days will be the base of the trunk big branches evenly coated brush, conditional farmers can use straw and other binding trunk; Six is to shake the tree snow removal.
Livestock and Poultry: Both heat preservation and ventilation
One is to close the doors and Windows, to prevent the cold air during the livestock and poultry shed temperature dropped substantially. But also pay attention to timely ventilation in livestock and poultry shed, keep the air fresh, prevent the occurrence of diseases. The second is to use heating facilities such as large watt bulb, increase the temperature inside the house, to ensure that livestock and poultry have a suitable environment for activities. Third, outside the house livestock and poultry such as sheep, cattle, such as local chickens to hurry back in time to avoid exposure to cold death. Four is in the livestock and poultry shed auxiliary on the mat grass, to prevent livestock and poultry from being cold. Five is the farm households as far as possible to prepare enough feed and forage grass, to prevent the snow may produce fodder forage supply and transport difficulties.
Fishery: it is important to do a good job in preventing pressure and collapse
Local fishery administrative departments shall, according to the situation, do well the work on duty, timely issue early warning information to aquaculture enterprises and farmers, and do a good job in preventing from freezing and collapsing. Further strengthen supervision, supervise and urge the maintenance of breeding insulation facilities, greenhouses, etc., to prevent the adverse effects brought by cooling, snowstorms, strong winds and fog. Timely instruct farmers to remove snow from aquaculture facilities to ensure the safety of fish and aquaculture facilities.
