Using 1289-2017 paleoclimate data, the researchers linked extreme cold events in southern China to the size of autumn sea ice in the Arctic, and found a stronger link since the 1980s. Professor at Beijing Normal University. Tsunde Xiao from the Northwest Institute of Environmental Environment and Resources (NIEER) of the Chinese Academy of Sciences (CAS). Zhiheng Du and Dr. A joint research team led by Jiao Yang discovered how extreme cold events happen. It is linked to the autumn spread of sea ice in the Arctic in southern China.

The research was published in the journal Advances in Atmospheric Sciences 14 April 2023.

In recent years, record low temperatures and severe snowstorms have hit many parts of East Asia. Numerous studies have shown that these extreme events are associated with the loss of Arctic sea ice by facilitating further blocking events and subsequent entry of arctic air into mid-latitudes. However, sea ice extent (SIE) shows significant annual variability, and there is no clear understanding of the relationship between long-term sea ice variability and extreme cold in Chinese history.

Fortunately, there is ample specimen or paleoclimatic evidence from sources such as ice cores, tree rings, and historical documents that can help reconstruct the decade-long relationship between the autumn SIE in the Barents and Black Seas and the onset of extreme cold. Wave events in southern China (ECWE).

The researchers selected historical periods from 1289 to 1911 and got information about the extreme cold in China from a book called “The Summary of the Chinese Meteorological Record for the Last 3000 Years.” The book collected evidence from 48 ancient Chinese books, reviewed 8,000 historical documents, and evaluated more than 200,000 weather-related records.

They also compared the records selected for the study with the climate records of historical Chinese dynasties and other relevant sources. Meanwhile, modern reanalysis data has been used to predict extreme cold from 1872 to 2017.

Professor Xiao said, “We found that the occurrence of winter ECWEs in southern China and autumn SIEs in the Arctic Barents-Kara Seas was a significant antiphase-relationship during most periods of sea ice retreat from 1289 to 2017.” Said.

The team also found that since the 1980s, ECWE’s response to low SIE has intensified during a period of sustained SIE decline. Additionally, the North Atlantic Oscillation and Siberian High played an obvious but precarious role as a “bridge” between SIE and ECWE over a ten-year timescale.

“As we saw this spring, weather events like dust storms are becoming more frequent and temperatures are relatively high. These phenomena may be related to the anomalous area of ​​Arctic sea ice,” said Dr. Zhiheng Du.

“We are also monitoring these events closely to continue to re-establish links between extreme weather or climate events in the low or mid-latitudes and elements of the Arctic cryosphere in the future. We hope to provide a clear explanation for why such events occur in historical times,” said Dr. Jiao Yang. .

Paleoclimate data can help overcome known limitations in observations and model simulations. However, quantitative surrogate-based registries need to be expanded with sufficient precision in the future and compared with climate models to provide more evidence to understand the mechanisms involved and draw solid conclusions.