【Event】
this winter, Beijing has also been no snow.
Beijing Meteorological Bureau, observations show that in 1951 a full 60 years since meteorological records, the Beijing First Snow at the latest time is January 29, 1984. Jan. 23 interview with reporters learned that under the current weather forecast, the future city of Beijing and a week are less likely to snow, snow last 60 years, the latest record is likely to be broken.
whether there is snow there are clear criteria, the Council can not be identified as the snow to snow
.
the Beijing Observatory (located in Yizhuang Economic Development Zone, Daxing District) in 1951 with a full 60 years since meteorological records of monitoring data, Beijing, the average annual snow day is November 29, the following year under the winter snow the situation appeared so far only 5 times, first snow in 1984 at the latest date is January 29.
Today, twenty-four solar terms in the last solar terms This winter's first snow Beijing is still slow to come down, approaching 60 years of the latest record.
Climate Center, Beijing Meteorological Bureau engineer Chen Dagang told reporters that Beijing Observatory observations show that from October 25 last year to now, no effective precipitation has been, to January 23 has been long up to 91 days. Currently, Beijing appears moderate in most parts of the meteorological drought.
noon on December 29 last year, in Beijing's Chaoyang District, Haidian District and other regions, the sky snow flakes scattered, people were happy to think that ushered in the long-lost snow. But the snow is just flash in the pan, along with the emergence of the sun, snow will soon stop, to let people disappointed.
meteorological station, according to Qiao Lin, Beijing introduced to determine a clear Beijing and snow weather criteria: First, individual work stations in the city's 20 stations observed in more than 10 snow; Second, Chaoyang District, Haidian, Fengtai, Shijingshan, the southern suburbs of Observatory weather station, and all five were observed in the snow, or the city these 5 stations more than 3 points in the observed snow, at least one station measured snowfall ≥ 0.1 mm. One of these two conditions met the first snow days in winter, snow can become at the Beijing area.
weather experts believe that the December 29 last year, the snowfall in Beijing focused on the individual sites are localized phenomena, snow days do not meet the criteria, it is not recognized as Beijing and snow.
forces mainly due to strong cold air, cold and warm air meeting point of departure from Beijing, the water vapor is not good
Qiao Lin said in an interview, snow requires warm and cold air meets the need for with adequate moisture conditions. Beijing less snow in winter, and the special geographical situation of the relevant, Beijing west, north are the mountains, troughs of low pressure (relatively low pressure weather system) is blocked by mountains, the rise in front of the trough weakened movement, making it difficult low-level water vapor rising under the action of air, condenses into clouds and the formation of increased snowfall.
, said Qiao Lin, Beijing rain and snow this winter is particularly scarce, mainly due to strong cold air forces, the water vapor is not good. Cold high pressure control in the Beijing area, the northerly wind and more cold air mass in the poor conditions of water vapor; other hand, the strong cold air forces, resulting in warm and humid air able to come south, is relatively weak. Water vapor is not good, it is difficult to form snow. Winter, cold air and warm air meeting point of departure from Beijing, the main intersection in the south of Beijing, Beijing, Hebei, south of Baoding, Shijiazhuang and other places have appeared in snow.
Beijing after the winter cold air forces is very strong, not only blown away the warm water vapor, but also lead to low temperatures, the public generally feel the cold weather than in previous years. According to Chen Dagang introduced in Beijing in winter, including last year's December to next February, a total of three months, now most of the past winter, and Beijing's average temperature lower than normal less than 1 ℃, 1 月份 so far, the temperature ratio year low by more than 1 ℃.
meteorological drought on winter wheat, the air quality impact is not large, the winter snow does not appear less likely
has been no snow in winter, bringing the impact of what ?
Chen Dagang, said that Beijing appears moderate in most parts of the meteorological drought, impacts on agriculture are mainly wheat, impact of the current situation is not particularly great. Last September and October, more rainfall in Beijing, sowing of winter wheat is good. Evaporation of this season than the smaller, dormant winter wheat, winter wheat has little effect on meteorological drought. However, warmer temperatures after spring, increased evaporation, winter turning green requires water, add water if there is no snow, then winter is not conducive to green and may die. If you do not have enough rain and snow in February, the agricultural sector to make irrigation water to prepare.
Chen Dagang, said that although this winter has been no snow, but a prominent feature is the cold air more frequently, how long can not be separated from a wind blowing, which purify the air, improve air quality benefit.
snowfall this winter will not appear? Chen Dagang, said from Beijing 60 years of observation record, has not yet appeared no precipitation in the winter, the entire winter, snow is not less likely to occur, there should be rain and snow in February.
Chen Dagang reminded that the average annual precipitation of 2010 Beijing 481 mm, 100 mm over the past year less than normal. Beijing in recent years, the average annual precipitation is less than normal, and all reservoirs are at less than normal water storage capacity of the state. In the case of less rainfall, the public should raise awareness of water conservation; the absence of snow, Droughts, to enhance the awareness of fire prevention; In addition, there is no snow in the weather, easy to get colds and respiratory and other diseases, relatively weak physical people should try to stay away from crowded places, pay attention to disease prevention. (Xinhua Liu Yi)
No comments:
Post a Comment