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Monitoring shows that since June this year (as of July 12), the average number of high temperature days in my country has been 5.3 days, which is 2.4 days more than the same period of normal years, the most in the same period in history since 1961. The Central Meteorological Observatory continued to issue an orange high temperature warning on the 14th.
Since June 13, my country has experienced the first regional high temperature weather process this year, with a wide range of influence, long duration and strong extremes. As of July 12, the high temperature event has lasted for 30 days, covering a land area of 5.021 million square kilometers and affecting a population of more than 900 million. There are a total of 71 national meteorological stations in the country where the highest temperature exceeded the historical extreme, among which the daily highest temperature in Hebei Lingshou, Gaocheng, Zhengding and Yunnan Yanjin reached over 44°C.
Affected by high temperature weather, the power grid load in Hebei, Henan, Shandong and other places hit new highs; soil moisture in eastern Zhejiang, western Henan, southern Shaanxi, southern Gansu, northern Sichuan and other places deviates, and drought conditions continue or develop in some areas; Zhejiang, Sichuan, etc. Many people have been diagnosed with heat stroke.
According to the monitoring of the National Climate Center, in June this year, the global average temperature was about 0.4°C higher than normal, the highest since 1979, with more than 2°C higher in northern Russia and western Europe. Since the beginning of the 21st century, high temperature and heat waves in the northern hemisphere have become more frequent in summer.
The data shows that the typical years of large-scale sustained high temperature events in my country in this century are 2003, 2013, and 2017. Overall, this year’s high temperature event started earlier than the above three years, and the duration and number of historical extreme stations are currently less than these three years. Although the scope of influence and the highest temperature per station are not as good as those in 2017, they have exceeded those in 2003 and 2013. year.
The sixth assessment report of the United Nations Intergovernmental Panel on Climate Change (IPCC) pointed out that in the past 50 years, global warming has occurred at an unprecedented rate since the past 2000 years, and the instability of the climate system has increased. According to the analysis of the National Climate Center, global warming is the climate background for the frequent occurrence of high temperature and heat waves in the northern hemisphere, and the abnormal atmospheric circulation is the direct cause of the frequent occurrence of high temperature and heat waves in many places around the world since June.
Since June, over the subtropical region of the northern hemisphere, the subtropical high pressure in the western Pacific, the Atlantic high pressure and the Iranian high have all strengthened in stages, thus forming a large-scale global warm high pressure belt. Under the control of the warm high pressure belt, the prevailing downdraft air flow is conducive to the warming of the ground. In addition, under the action of the large-scale high pressure belt, the air is relatively dry, and it is not easy to form clouds, which also makes it easier for solar radiation to reach the ground, resulting in frequent high temperature and strong intensity.
Specific to my country, the ongoing La Niña event also provides an important climate background. According to statistical analysis, in the summer following most La Niña events, the subtropical high in the western Pacific tends to move northward. Since late June, the subtropical high has been rising northward, especially after Typhoon “Siamba” moved northward in early July, the subtropical high has strengthened to the west, the Iranian high has been extended eastward, and combined with the mid-latitude continental high, it has formed a stable over our country. Warm high pressure belts, which in turn cause a wide range of high temperature weather. In addition, the water vapor carried by the subtropical high also makes the central and eastern regions of my country relatively humid, resulting in higher body temperature.
According to the forecast of the Central Meteorological Observatory, from the 17th to the 20th, rainfall will occur in the Sichuan Basin, Jianghan, Jianghuai, western and northern Jiangnan, and northwestern South China. weather. After the 21st, the high temperature in the southern region will develop again and the scope will expand. The daily maximum temperature in Fujian, Jiangxi, southern Zhejiang and other places can reach 39 to 41 °C.
According to Xinhua News Agency, Beijing, July 14.Return to Sohu, see more
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