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Cold wave

2019-03-14  |   Editor : houxue2018  

Summary of cold wave

Cold wave is a kind of disastrous weather in winter, often called cold current. The so-called cold wave is a weather process in which the cold air from the North extensively invades our country southward, causing a large-scale sharp cooling and northerly gale.Cold waves usually occur in late autumn, winter and early spring.The Meteorological Department of our country stipulates that the cooling caused by cold air intrusion can reach above l0 °C in a day, and the minimum temperature is below 5 °C, so the cold air outbreak process is called a cold wave process. It can be seen that not every cold air southward is called a cold wave.

(1)Cold wave formation: China is located in the southeast of Eurasia.Located in the high latitude Arctic region and the Siberian and Mongolian plateau, the ground and atmosphere get less heat all year round due to the weak sunlight, and the ice and snow all the year round.In winter, when the direct position of sunlight crosses the equator and reaches the southern hemisphere, the degree of cold in the Arctic region becomes more intense and wider, and the temperature is generally below - 40°to - 50°C.A large range of cold air masses gather to a certain extent,under the action of the appropriate atmospheric circulation at high altitude, they will invade southward on a large scale and form cold wave weather.

(2) Key cold wave areas: According to the statistics of the Central Meteorological Observatory, 95% of the cold air passes through central Siberia (70°〜90°E,43°〜65°N) and accumulates and strengthens there, this area is called the key cold wave area.

There are three main paths for the cold wave to invade China: (1) The west route: from West Siberia to Xinjiang, and from Hexi Corridor to southeast;(2) Middle Road: After entering China from central Siberia and Mongolia, it goes down through Hetao area and central and southern China;(3) Entering northeast China from Eastern Siberia or Eastern Mongolia and descending southward through North China;(4) East Road Jiaxi Road: East Road cold air from the lower reaches of Hetao to the south, West Road cold air from the southeast of Qinghai, two strands of cold air often converge on the eastern side of the Loess Plateau, the Yellow River and the Yangtze River, resulting in a large range of rain and snow weather when confluence, and then two strands of cold air merge southward, resulting in strong winds and obvious cooling.

Cold wave effect

Cold wave is a large-scale weather process, which can cause severe cooling, strong wind and snowstorm in a wide range along the way, the disasters caused by cold wave, such as strong wind, frost, snow disaster, rain and so on, have a great impact on agriculture, transportation, electricity, navigation and people's health.After the rain and snow, the road was ice and slippery, and traffic accidents increased significantly.Cold wave is very harmful to human health. Wind and cooling weather can easily lead to cold, tracheitis, coronary heart disease, pulmonary heart disease, stroke, asthma, myocardial infarction, angina pectoris, migraine and other diseases. Sometimes it can aggravate the patient's condition.

Guizhou is the most frequent area of Rainstorm in China, followed by Hunan, Hubei, Henan and Jiangnan provinces and regions.In the northern region, there are more rainbows in Shandong, Hebei, Liaodong Peninsula, Shaanxi and Gansu, and more in the southeastern part of Gansu and Guanzhong area of Shaanxi, while in Sichuan, Yunnan, Ningxia, Shanxi and the coastal areas of South China, there are few rainbows.

At the same time of causing disasters, cold wave will also bring beneficial effects. Cold Waves help exchange heat on the earth's surface.With the increase of latitude, the earth receives less solar radiation energy, so the earth forms tropical, temperate and cold zones.Cold tides carry a large amount of cold air pouring into the tropics, making a large-scale exchange of ground heat, which is very helpful to maintain the ecological balance of nature and maintain the flourish of species.Meteorologists believe that the cold wave is the guarantee of smooth weather. Affected by the monsoon, China has a dry climate in winter and a dry season.But when the cold wave invades southward, it often brings a wide range of rain and snow weather, alleviates the drought in winter, and benefits crops.

Experts on crop pest control believe that the low temperature brought by cold wave is the most effective natural “insecticide” at present, which can kill a large number of pests and pathogens latent in the soil for winter, or inhibit their breeding, and reduce pests and diseases in the coming year.According to the survey data of agricultural technology stations around the world, pesticides can save more than 60% in the year of heavy snow blocking winter.

Prevention of cold wave

(1) Warning signals of cold wave

Warning signals of cold wave are divided into four levels, which are blue, yellow, orange and red, respectively. Shown in table 6-11.

(2)Prevention of cold wave

①When the temperature drops suddenly, we should pay attention to adding clothes to keep warm, especially the hands and faces.

②Close doors and windows and fasten outdoor structures.

③Beware of slipping and falling when you go out.

④Old and weak patients, especially cardiovascular patients, asthma patients and other people sensitive to temperature changes, try not to go out.

⑤Pay attention to rest and don't be overtired.

⑥Households heating with coal stoves should be on guard against gas poisoning.

⑦Weather forecasting should be strengthened and accurate cold wave news or warnings should be issued in advance.

⑧Publish accurate cold wave news or warning to enable ships to return in time.

⑨Prepare crops, livestock, etc. for cold prevention in advance.

Mitigation of meteorological disasters

Against the background of global warming, increasing extreme weather and climate events, frequent and increasingly serious meteorological disasters, it is particularly important to do a good job in preventing and mitigating meteorological disasters.

At present, China has established a relatively modern and perfect meteorological disaster monitoring network, and has initially established a three-dimensional observation system consisting of ground observation, altitude detection and satellite remote sensing detection.China has launched five polar orbit meteorological satellites and four geostationary meteorological satellites. Especially since 2000, China's Fengyun-1 and Fengyun-2 satellites have been accepted by the World Meteorological Organization (WMO) as an important member of the Global Earth Observation System (GEOSS).Users all over the world can receive and make use of China's Fengyun meteorological satellite data free of charge. At present, more than 21,000 meteorological observatories have been built in China, of which 2,435 are all-factor national-level automatic meteorological stations, and 19,000 are regional meteorological observatories. In addition, there are some special and single observatories, mainly observing rainfall, temperature, wind speed and wind direction.More than 150 GPS ground-based meteorological observatories and 3 National observatories have also been completed.China has also upgraded four atmospheric background stations, launched the construction of three new atmospheric background stations, and initially built the National Atmospheric composition, acid rain, dust storms, lightning monitoring network.

Main measures for mitigating meteorological disasters

(1) Strengthen disaster prevention system and infrastructure construction according to law. Governments at all levels should step up their investment in meteorological disaster prevention.

(2)Strengthen the forecast of meteorological disasters.Meteorological departments should continue to strengthen research on the formation mechanism of weather, climate disasters and meteorological secondary and derivative disasters, so as to improve the accuracy, timeliness and effectiveness of disastrous weather and climate prediction and early warning.Weather disaster prevention planning should be well formulated and implemented, meteorological disaster prevention plans and emergency plans should be established and perfected, emergency management of meteorological disasters should be strengthened, and emergency disposal level and meteorological disaster prevention ability should be improved.

(3)We will strengthen the construction of an emergency system for meteorological disaster prevention.Relevant departments should strengthen the construction of linkage mechanism for meteorological disaster prevention and emergency response, realize information exchange, resource sharing, unified command, division of responsibilities and rapid response;broaden the channels for issuing emergency information of meteorological disasters and collecting disaster information, radio, television, newspapers, the Internet and other news media, communication and information service units should timely transmit and disseminate early warning information of meteorological disasters, and public places such as schools, hospitals, stations, stadiums and gymnasiums should designate emergency contacts for meteorological disasters,electronic display screens for meteorological disaster warning information should be set up, and rural areas should gradually be equipped with obligatory meteorological disaster informants.We should regularly investigate the hidden dangers in the prevention of meteorological disasters, constantly improve various defense plans, organize relevant departments and the masses to conduct emergency drills for meteorological disasters, and improve the speed of emergency response, the ability of coordination and linkage, the ability of emergency handling and the level of management.

Countermeasure of disaster prevention and reduction

(1)Take disaster prevention, resistance and relief as a systematic project.From a systematic point of view, we should establish and improve the monitoring network of disastrous weather and changes of ecological environment, improve the monitoring and tracking ability, establish and improve the prediction and prediction system, deeply analyze the occurrence, development and evolution of various natural disasters, and improve the long, medium and short-term forecast, especially the medium and long-term forecast level;establish and improve the information system, through the collection, feedback, transmission, processing and processing of various related information, so that information can be obtained comprehensively, timely and reliable, and improve the ability to identify disasters and disaster areas;establish and improve the command and decision-making system, coordinate the decision-making of material allocation, capital investment, and early planning, late management, remedial measures, action plans, etc., so as to achieve comprehensive management and achieve the best overall system benefits.

(2)Raise the awareness of disaster prevention and mitigation of the whole people. Strengthen propaganda and education so that people can truly realize that disaster reduction is also an increase in income, and disaster prevention is an important act of disaster reduction. Many facts show that prevention is quite different from prevention. Only when we understand it can we give full play to and mobilize people's subjective initiative in the practice of disaster prevention and mitigation.

(3)Strengthen the study of disaster economics. It is necessary to organize the strength of relevant disciplines, work together to tackle key problems, carry out comprehensive, systematic and comprehensive research on major disasters throughout the country, and provide theoretical basis and ways for optimizing plans and scientific decision-making for natural disaster prevention.

(4)Strengthening the legal system is also an important part of disaster prevention, resistance and relief.We should further improve and enrich the existing laws and regulations and abide by them.Some urgently need to establish new laws and regulations. Efforts should be made to prevent the decline of resources and the deterioration of the environment, to further coordinate the relations among production, life and environment, to achieve the organic integration of economic, social and ecological benefits and to give full play to the overall functions, so as to improve the efficiency of energy conversion and material circulation, so as to further enhance the ability to resist natural disasters, minimize disaster losses and promote economic growth.

(5) Take the road of scientific development. In order to prevent and mitigate natural disasters, we must adhere to the scientific development path, respect the natural and scientific laws, change the current development model of natural resources approaching plunder, change from purely pursuing economic growth in the past to adhering to people-oriented, achieve comprehensive, coordinated and sustainable economic and social development, strive to improve the ecological environment and strengthen natural resources such as the atmosphere. Protecting, continuously strengthening the ability of sustainable development, promoting the harmony between man and nature, and promoting the whole society to embark on the road of civilized development with productive development, rich life and good ecology.

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