Data news, meteorological data, looking back at high temperature weather
Expert Consultant: Liu Lu, Senior Engineer of Meteorological Service Office of Central Meteorological Observatory.
August 23 is the last day of the last day, and the dog days of 40 days are coming to an end. As the saying goes, "the heat is in the dog days", which is often the hottest period in a year. After the dog days, the summer heat is weakening. Although some parts of southern China are still in hot weather, most areas are about to withdraw from the "high temperature circle".
Is the high temperature abnormal this summer?
High temperature is a common weather phenomenon in summer. It can be defined as high temperature weather when the highest temperature on that day exceeds 35℃, and high temperature for several days in a row constitutes a high temperature heat wave.
It can be seen from the occurrence time of the highest temperature in various places since June this year that the high temperature weather in China has obvious characteristics of regional changes in stages. The main position of high temperature in June is located in North China, Huanghuai and other places. Under the control of warm and high pressure in the mainland, the weather in this area is sunny and sunny in partly cloudy, with strong solar radiation and strong near-surface heating, which is easy to form continuous high temperature weather; In July, with the extension of subtropical high to the west, the plum rain in the south ended, the rain belt moved northward, the rainfall in the north gradually increased, and the high temperature eased. At the same time, the subtropical high stayed in the south for a long time, and the high temperatures in Jiangnan, northern South China, eastern Jianghan and Jianghuai developed and continued.
Since July 3rd, large-scale high-temperature weather has occurred in Jianghuai, Jianghan, Jiangnan, South China, Sichuan and Chongqing. The high-temperature duration in Zhejiang, Fujian, Jiangxi, Hunan, southern Jiangsu and Anhui is long, and the number of high-temperature days in some areas has reached more than 30 days, and in some areas of Zhejiang and northeastern Jiangxi, it has exceeded 40 days. Among them, the high temperature in Zhejiang is extremely extreme, and 10 national observation stations have exceeded the historical extreme value of the highest temperature. The highest temperature in more than 60% of the stations has reached above 40 C, and the highest temperatures in Yiwu, Lishui and Jiande have reached 42.8 C. Hangzhou ranks first among municipalities and provincial capitals in terms of high temperature days and continuous high temperature days. The temperature of 41.9℃ on August 3rd became the highest among municipalities and provincial capitals this year.
The weather is getting hotter and hotter, which is also reflected in the early and more high-temperature warnings.
According to the "Measures for the Issuance of Meteorological Disaster Early Warning of the Central Meteorological Observatory", the high temperature early warning is divided into three levels, from weak to strong, namely yellow early warning, orange early warning and red early warning. So far this year, the Central Meteorological Observatory has issued 61 yellow warnings and 34 orange warnings for high temperature weather. From June 9 to 15, the first regional high-temperature weather process occurred in China this year, four days earlier than normal. The first high-temperature orange warning was released on June 10, 12 days earlier than the first high-temperature orange warning in 2023.
With the climate warming, in recent years, the national average temperature has hit record highs. According to the statistics of the Central Meteorological Observatory, the national average temperature from June 1 to August 22 this year was 22.2℃, which was significantly higher than the normal period (21.3℃), ranking second only to 2022 (22.4℃) since 1961.
What needs special reminder is that at present, the high temperature in some areas such as Chongqing and the middle and lower reaches of the Yangtze River continues. Up to now, Chongqing is still in the highest level of high temperature red warning. According to the forecast of the Central Meteorological Observatory, from August 24th to 27th, the hot weather will continue in Sichuan, Chongqing, southwestern Shaanxi, Guanzhong, Hubei, Hunan, Jiangxi, Anhui and other places, with a daily maximum temperature of 35.℃To 37℃, Sichuan, Chongqing and other local areas can reach 40℃To 42℃; After 28th, the high temperature weather in the above areas has eased, but the high temperature in Sichuan and Chongqing will last until the beginning of September. Please ask the public in the above areas to take measures to prevent heatstroke and reduce outdoor activities during high temperature periods as much as possible; High temperature weather will lead to an increase in electricity consumption. Please pay attention to the safety of electricity consumption and turn off the power supply of all kinds of electrical equipment before going out to prevent fire accidents caused by short circuit or fever of electrical appliances.
High temperature sweeps across the northern hemisphere
High temperature weather not only appears in China, but also affects most parts of the northern hemisphere, and it also comes earlier and stronger. At present, hot weather is sweeping across many European countries, with the highest temperature in Italy, Germany, Serbia and other countries exceeding 40℃.
In March this year, the World Meteorological Organization (WMO) released the Report on Global Climate in 2023. According to the report, 2023 became the hottest year since meteorological records began, and the average temperature near the surface was 1.45℃ higher than the pre-industrial level. The concentrations of three main greenhouse gases, carbon dioxide, methane and nitrous oxide, are still rising. The concentration of carbon dioxide is 50% higher than that before industrialization, and the world is in an unprecedented warming process.
Under the climate background of global warming, the average temperature rises, high temperature weather tends to be frequent, and extreme high temperature events increase or become the new normal. The meteorological department will strengthen the monitoring and forecasting of high-temperature weather, formulate emergency plans to deal with extreme weather, release early warning information in time, remind the public to take precautions, strengthen the publicity of popular science, make the public better understand the impact of climate change on life, take the initiative to take self-protection measures, and enhance the adaptability of the whole society to climate change.
(Author: Su Jessie Editor: Yan Hong)