The temperature in Beijing is the lowest since 2 1 century. What is the reason for the cold weather?

Beijing may set the lowest temperature record since 2 1 century, and there is no hope of heavy snow under this cold wave. The cold air arrived as scheduled, and the temperature in the southern suburbs was -9.4℃. The north wind roared, the wind-cold effect was obvious, and the body felt very cold. Be sure to do a good job of wind, cold and antifreeze when going out. Pay attention to protection in yellow warning of strong wind and low temperature. However, this time there is only strong cold air from Siberia, and there is no warm and humid airflow. It seems that there is no hope of snow.

In response to the gale cooling process, the Beijing Meteorological Observatory has issued a yellow warning signal for gale and a yellow warning signal for continuous low temperature. There will be about 5 northerly winds in most parts of the city, with gusts of 8 and 9. Affected by strong cold air, the city will continue to have low temperature weather, and the lowest temperature in the plain area is below-12℃. The cold air process did not lose to the New Year's cold wave at the end of the year. First, the cooling range is large, and the cooling range is 6~8℃. It is expected that the temperature will drop to the lowest point, and the highest temperature in the plain area will drop to about -9℃ during the day and the lowest temperature at night will drop to about-16℃. The minimum temperature in mountainous areas dropped to -22 ~-20℃. Second, the wind-cold effect is obvious. From morning to night, the northerly winds are four or five, the plains are seven or eight, the mountains are nine, and the northerly winds are three or four. Low temperature lasts a long time. The temperature continues to be low, and the lowest temperature at night is below-10℃.

The reason of low temperature weather is that the surface temperature of the earth is mainly caused by solar radiation. If the sun radiates strongly to the earth, the earth will be hot; Otherwise, it will be cold if it is weak. The rotation of the earth around the sun is elliptical. Winter is a prominence, which means that the sun's radiation to the earth is very weak during this time, so the temperature of the earth is very low. Because of the revolution of the earth, in winter, one side of our earth is far from the sun, that is, the other side of the earth faces the sun in summer. We are behind the sun, so it will be very cold. Although we can see the sun every day, the sun does not directly shine on us. Who scattered the sunlight? In our country, the northwest wind (winter wind) blows in winter, which brings cold air to all parts of the country, often on the basis of low temperature, and then greatly cools down.

In cold weather, it is very important to prevent myocardial infarction and cerebral infarction and keep your face warm. The sudden drop of temperature will lead to vasoconstriction, and the atherosclerotic plaque on the vascular wall of some patients will rupture and form thrombus, which will occur in the cerebral vessels, lead to cerebral infarction, and occur in the heart, which may lead to acute attack in patients with myocardial infarction or coronary heart disease. Jin Zening, director of the Center for Cardiology and Macrovascular Diseases of Beijing Tiantan Hospital, reminded us that these situations are very critical. Many heart patients will feel angina pectoris and other symptoms as soon as they go out in cold weather. It should be noted that temperature difference is a very important risk factor. The greater the temperature difference, the greater the risk of vasospasm. The temperature in the office and home should not be too high, and don't wear too thick clothes indoors. In addition, in order to keep out the cold, we should consciously put on thick down jackets and warm boots, but often ignore the important parts of the face, so we should wear masks and scarves to protect the face.