Is the sky that Cantonese people see this morning gray?
In the early morning of 13/0, Weibo @Guangdong Weather Reminder: The sand and dust carried by the north wind has been blown into Guangdong from the north, and the concentration of particulate matter in some areas has exceeded the standard.
The national sand and dust weather forecast map released by the Central Meteorological Observatory shows that the southernmost sand or floating dust has reached Hainan Island. Weibo @Central Meteorological Observatory sighed: The impact of the dust this time is too large, all the way to South China.
Why can sand and dust cross the Nanling Mountains to Guangdong?
Let's first look at why the Qinling Mountains and Daba Mountains, which have higher average altitude and are located further north, have not been able to stop the dust.
Chuanguan News reporter previously interviewed Zhang Junke, associate researcher and director of the School of Environmental Science and Engineering of Southwest Jiaotong University, Zhang Junke introduced that under the background of drought and windy weather in the sand source this year, sand and dust were carried into the air at a height of thousands of meters by rounds of wind, with a wide transmission path, and large-scale and long-distance transmission can be achieved under the guidance of high-altitude air flow. Although the average elevation of the Qinling Mountains is about 3700 meters, and the ridge is about 0 meters high, it cannot completely block the wind and sand. In addition, the difference between cold and heat before and after the arrival of cold air caused a very strong gradient wind, which also contributed to the southward movement of sand and dust.
After crossing the Qinling Mountains and Daba Mountain, the sand and dust are almost facing the "Pingchuan River". The strong winds and the absence of rain for the dust to settle also contributed to the further southward movement of the dust.
Weibo @Central Meteorological Observatory analysis, first of all, there are strong sandstorms in the upstream area, and the amount of sand is very large; secondly, the wind at high altitude is strong, the moving speed is fast, and the sand and dust travel farther. Third, sand and dust are transported along a northerly path, which makes it easier to penetrate into the south. Fourth, there is no rainfall during the spread of sand and dust.
據中央氣象台，上一次影響到南方的沙塵天氣還要追溯到2010年3月19日-22日，福建、臺灣等地出現浮塵天氣。這次沙塵影響到兩廣地區和海南島，的確少見。預計今天，南方地區仍將受沙塵天氣影響，明天基本結束。
The excess pollutant is PM10, and it is recommended that children, the elderly and the sick stay indoors as much as possible to avoid physical exertion, and the general population should minimize outdoor activities.