Why does the Siberian cold current have such a great influence on China's climate?

For China people, Siberia is a distant and familiar place. Every year, cold air from this vast northern region frequently patronizes China, where the climate, environment and ecology have a great influence on China.

Following the joint scientific investigation by Chinese and Russian scientists in Lake Baikal last August, scientists from the two countries joined hands again and began a two-week field trip in Siberia on July 22 this year. As of August 4, the scientific research activities have basically ended and achieved satisfactory results.

Scientific research in Siberia is of great significance.

Siberia is a region with huge energy and mineral reserves, which has not been fully developed. There are not only huge reserves of oil, natural gas, coal, various metals and nonmetals, but also abundant hydropower and biological resources. Only Lake Baikal, the deepest lake in the world, accounts for one fifth of the fresh water in the world. In addition, the forest coverage area and timber volume of Siberia account for a large proportion in Russia and even the whole world.

Scientists point out that this area is the "green barrier" of China's ecology, and the cold air that affects China is formed from this area, so the local climate, environment and ecology have a great influence on China.

Liu Jiaqi, the Chinese chief scientist of the Sino-Russian Siberian joint expedition and academician of the Chinese Academy of Sciences, told the reporter that under the background of increasingly close political, economic, trade and cultural ties between China and Russia, scientists from both sides are committed to carrying out multidisciplinary scientific research in this region.

Academician Liu Jiaqi emphasized that the scientific and technological cooperation between Chinese and Russian scientists in the fields of resources and ecological environment in Siberia is of positive significance to promoting the scientific and technological progress of the two countries, enhancing the level of scientific and technological cooperation and promoting the development of related industries.

At the same time, other scientists conducted fixed-point investigations on aquatic organisms and lake environment in Lake Baikal and the Selenger River Delta.

Siberian forests affect the ecology of China.

Siberia has a vast territory, complex and diverse natural environment, and most areas are covered by forests. Scientists from China who participated in the joint scientific research believe that Siberian forest, as an important part of the local ecosystem, has a great impact on the ecological environment of China.

The forests in Siberia mainly belong to the Taigarin, that is, the northern coniferous forest. Zhuang Dafang, a professor at the Institute of Geographical Sciences and Resources of the Chinese Academy of Sciences, said that the Siberian Taijialin, with spruce, fir, pine and larch as typical tree species, is very sensitive to global climate change. With the increasing influence of human activities on nature and global warming, the forests here may shrink from the north or extend to the south, which will directly affect the ecological environment of China. For example, the change of coniferous forest biomass will affect the frequency and intensity of cold current in winter in China and so on.

The cold air from Mongolia and Siberia and the warm and humid air from the Pacific Ocean are considered to be the two major factors that affect the climate in China.

Zhuang Dafang said: "In winter, the cold current going south will lead to strong winds and cooling. In early spring, once cold air is generated over Siberia, it is likely to bring dust from the Mongolian Plateau to Beijing and other parts of North China, causing dusty weather. "

Zhuang Dafang emphasized that under the background of global climate change, exploring the evolution law of ecosystem is one of the focuses of environmental research.

In the Sino-Russian Siberian joint scientific research, Chinese and Russian expedition members selected samples from wild forest areas to obtain their wood reserves, forest type composition, biomass and other indicators, and used this to verify the data obtained by remote sensing technology.

The Yangtze River Delta helps the Yangtze River.

Russian scientists who participated in the Sino-Russian expedition to Siberia ended their fixed-point investigation in the Selenger River Delta on August 4th. Expert say that studying that world's lar lake delta can provide important help for controlling lake pollution in China.

1024km-long Selenger River originates in Mongolia and meanders northward into Lake Baikal. Professor Hu Weiping from Nanjing Institute of Geography and Lakes, Chinese Academy of Sciences, said that the Selenger River has a large gap between the upper and lower reaches and flows through the desertification area, so the water carries a lot of sediment and deposits it at the mouth of Lake Baikal, gradually forming a huge delta with an area of nearly 700 square kilometers.

The Selenger River Delta is a vast area, which is basically in a natural state and has high scientific research value. In the past two weeks, three scientists from Nanjing Institute of Geography and Lakes, Chinese Academy of Sciences, selected 60 survey sites in various areas of the Delta and obtained tens of thousands of hydrological, water quality and ecological data.

Zhang Lu, a doctor of environmental chemistry at the institute, said that there are many rivers in the delta, and birds and various aquatic plants living here constitute a unique biosphere. It is precisely because the wetland has the function of filtering pollutants in the river water that the closer it is to Lake Baikal, the less sediment and pollutants there are in the river water, and the river water entering the lake becomes cleaner.

Scientists said that in addition to analyzing the protective effect of the delta on the surrounding environment, the data obtained in this survey will help to understand the changes of the bar sand in the Yangtze River estuary and the transport characteristics of the sediment at the tail of the Three Gorges Reservoir.