Study: Heatwaves in Central Asia Are Gradually Intensifying
Heatwave is a climatic phenomenon that occurs during continuously high-temperature weather. Central Asia, located in the hinterland of Eurasia, is one of the driest regions in the world, with relatively fragile desert ecosystems and aquatic ecosystems. Prof. CHEN Yaning’s lab at Xinjiang Institute of Ecology and Geography of Chinese Academy of Sciences (CAS) investigated the intensification of heatwaves in Central Asia from 1981 to 2020.
The researchers utilized meteorological station data and reanalysis data to assess the spatial-temporal characteristics of heatwaves in Central Asia with eight metrics. They also explored possible mechanisms leading to the intensification of heatwaves in this area, combined with key hydro-meteorological factors. This work was published in Journal of Hydrology on Nov. 5.
Results showed that heatwaves in Central Asia have significantly increased in frequency (0.10 events/year), intensity (0.81 °C/year), and duration (0.08 days/year), and the first yearly heatwave has occurred earlier. The highest values of the yearly total number of heatwave days (HWF), the total number of annual heatwave occurrences (HWN), and cumulative heat (HCH) are found in Kazakhstan.
Through preliminary attribution, they found that in north-western Central Asia, reduced precipitation and increased solar net radiation led to a significant decrease in soil moisture, exacerbating the intensity of heatwaves.
“The research could provide a scientific basis for predicting the intensity of future extreme heatwaves, thereby enabling the early prevention of potential adverse impacts on ecosystems,” said Prof. CHEN.
This work was done in collaboration with researchers from Xinjiang University, Sun Yat-sen University, Tsinghua University, and the National Center for Space Research and Technology of Kazakhstan.
Figure: Schematic diagram of heatwave processes in Central Asia under a warming scenario. (Image by WANG Xuechun)
State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and
Geography, Chinese Academy of Sciences