Xinhua News Agency, Beijing, October 18 (Reporter Ni Yuanjin) The rainfall in Beijing this year's "ultra-long flood season" is unusually abundant.
This year, Beijing had 122 days of "ultra-long flood season", with 79 rains in total.
According to data from the Beijing Flood Control Office, out of 79 rains this year, the average rainfall reached 10 heavy rains and above, including 2 heavy rains. The city’s average rainfall was 792.6 mm, which was 425.7 mm and nearly 10 times higher than normal. The figures for the same period of the year were about 90% and 70% higher respectively.
Among them, the rainfall in Beijing in July was 400.4 millimeters, accounting for 50.5% of the total rainfall during the flood season, which was the largest in the same period since the monitoring records in 1951.
Wei Ke, an associate researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said that from a meteorological point of view, more rain will inevitably be accompanied by abnormal circulation, such as the abnormally northerly subtropical high in the western Pacific, the continuous maintenance of the disturbance of the westerly belt, and the abundant water vapor transport.
"As for why the abnormal circulation occurs and what are the conditions for its formation, we need to carefully study the conditions for the formation of abnormally warm sea temperature in the Northwest Pacific, the influence of Pacific activities on typhoons, and the influence of Arctic warming on the disturbance of the westerly circulation. "Wei Ke said.
The latest report released by the United Nations Intergovernmental Panel on Climate Change (IPCC) in August shows that global climate change is intensifying, and the probability of extreme events in many regions will increase. High temperature, heat waves and droughts will occur concurrently with storm surges, ocean waves, and tides. The extreme sea level event with flood as the main feature, and the compound flood event caused by the superposition of heavy rainfall has intensified.
Chao Qingchen, deputy director of the National Climate Center, said that the climate system exchanges heat through its atmosphere, ocean, ice, snow, ecology and many other elements. As climate warming intensifies, China’s average temperature is expected to continue to rise in the future. , Extreme heat waves have become more frequent, heavy precipitation and its induced floods have increased, and sea levels have risen further.
"For coastal cities, the combination of extreme rainfall, extreme river flow and more frequent extreme sea level events will increase the possibility of coastal flooding. In the future, the developed areas of eastern China will bear higher climate risks." Chao Qingchen said.
Wei Ke said that these extreme weather and climate events induced by climate change leave researchers with deeper propositions to be solved, including the phenomenon of southern droughts and northern floods caused by global warming, the impact of warming oceans on the climate, and global warming. Under the background, the frequency and intensity of extreme disasters change, and whether there is a tipping point in the impact of global warming on the East Asian monsoon region.