What was the ice disaster in 28?

Ice disaster and snow disaster refer to the natural phenomenon that a large area of snow and ice disaster is caused by freezing rain or snowfall for a long time.

2. Harm

1. Harm to the power supply network. As freezing rain falls from the sky and falls on the wires (and others, of course), it will immediately form solid ice. As a result, the icicles will become bigger and heavier, which will make the power supply network unbearable, causing damage and disasters.

2. For the harm of transportation, traffic accidents will easily occur due to the icing on the road.

3. For crops, it will cause serious frost disaster. Wait a minute.

Third, news examples:

On January 13th, 28, a rare snow and ice weather hit Guizhou Province, and the land in southeastern Guizhou suffered the biggest snow and ice disaster since 1984. By noon on January 21st, the power supply in seven counties under the jurisdiction of Qiandongnan Prefecture, such as Sansui, Tianzhu, Jinping, Liping, Congjiang, Rongjiang and Leishan, was interrupted one after another, and the cumulative number of affected households reached more than 129,8. (Xinhuanet)

On January 23rd, 28, Guizhou power grid was severely damaged by ice, and the power supply in seven counties in Qiandongnan Miao and Dong Autonomous Prefecture was cut off. At that time, eight emergency commandos composed of more than 2, employees of Kaili Power Grid were working around the clock to repair the power in seven counties. In Kaili City, Qiandongnan Prefecture, the armed police involved in repairing the power grid smashed the thick ice on the wires with submachine guns.

IV. Causes of the ice disaster in southern China:

In winter or early winter, cold air is less in most parts of our country, one is weak, and the other is less frequent. Because we all know that the two conditions that must be met for snow or rain are warm and humid airflow (the air must have considerable humidity, moisture and high temperature), which comes from the south and from the tropical region; Another condition is that there must be cold air, which comes from the polar regions and from the alpine regions. The cold air affecting our country in the early winter this year is relatively weak, and the frequency is not much. Even with the cooperation of warm and humid airflow, it is not easy to snow without cold air. Therefore, before January, there was relatively little precipitation, dry air and high temperature in most parts of our country. However, in January, great changes have taken place in the atmospheric circulation, which makes the cold air activity in our country more active. After the cold air is active, the warm and humid airflow at low latitudes is gradually strengthened, which just happens to combine the cold and the warm. Therefore, during this period of time, the cold air is relatively strong, the cold air activity is relatively frequent, and the warm and humid air flow is relatively strong. These two air flows have the same influence and meet coincidentally, so recently, especially in the Yangtze River basin, there have been more rainy and snowy weather, and the low temperature weather has been maintained for a long time. This is the main reason.

Also, it is caused by the cold front weather caused by the cold air mass formed by the Asian high originating from Mongolia and Siberia moving southward. But isn't it a little one-sided simply from the perspective of the Asian high and the cold front heading south? In that case, there will be low temperature and snowfall in eastern China every winter. But how to explain the reason for such a rare large-scale continuous snowfall this year?

after thinking, I think the most important reason for this abnormal weather phenomenon is La Nina. Under the influence of La Nina phenomenon, the water temperature in the equatorial western Pacific Ocean is high, and the water evaporation is increased, resulting in abnormal meridional circulation in East Asia. In addition, since the beginning of spring, the northerly airflow has prevailed in northern China, while the warm and humid airflow in the southeast is relatively weak. As a result, cold waves and strong winds frequently appear in the north. And we know that at this time, East Asia is being affected by the Asian high. Therefore, it has strengthened the power of cold air from Siberia to move south rapidly. After the cold air passes through the border, the temperature drops sharply, and it passes south through the blocking influence of Qinling Mountains and Daba Mountain, and stays in these areas for a long time. In addition, the warm and humid air flow from the Indian Ocean in the southwest to the north continuously increases the humidity and interacts with the cold air, thus forming a continuous orographic precipitation (snow). Perhaps it has caused the recent continuous low temperature and snowfall.