Source Xinhua 2020-05-29 181110Editor huaxia
BEIJING, May 29 (Xinhua) -- Chinese researchers have reconstructed precipitation changes in the recent 12,000 years of a transition zone in north China’s arid and semi-arid regions.
The East Asian summer monsoon (EASM) variability is primarily influential for climate change in East Asia.
The lakes in the transition zone of north China’s arid and semi-arid regions at the fringe of the EASM is sensitive about the response of the EASM. However, the pattern and mechanisms of the EASM change during the Holocene that began approximately 11,650 years ago are still debated.
The researchers from Lanzhou University, the Chinese Academy of Sciences and Nantong University hoped to study the pattern and range of the EASM change in a longer time scale and predict the precipitation inside the transition zone.
They conducted a systematical geomorphologic survey along a closed-basin lake located on the southern Mongolia plateau and reconstructed the precipitation quantity in the recent 12,000 years of the lake.
The research found that the EASM dominated annual precipitation varied between 420 and 280 millimeters during the Holocene period in the basin, indicating a generally semi-arid environment on the southern Mongolian plateau. And the basin was broadly covered by open steppe vegetation throughout the Holocene.
Moreover, the EASM precipitation intensity increased from the early Holocene to the beginning of the mid-Holocene, followed by a decrease during the late Holocene, according to a research article recently published in the journal of Quaternary Science Reviews.
The results showed that the EASM precipitation intensity generally decreased in recent six thousand years. The researchers predicted that north China’s arid and semi-arid regions would not witness apparent precipitation increase in the future. Enditem