Arid Zone Research ›› 2021, Vol. 38 ›› Issue (1): 1-11.doi: 10.13866/j.azr.2021.01.01

• Pan-Third Pole Environment and Green Silk Road •     Next Articles

Analysis of climate characteristics in the Pan-Central-Asia arid region

YAN Xinyang1,2,3(),ZHANG Qiang1,3(),ZHANG Wenbo2,REN Xueyuan1,WANG Sheng3,ZHAO Funian3   

  1. 1. College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, Gansu, China
    2. Meteorological Service Center of Gansu Province, Lanzhou 730020, Gansu, China
    3. Institute of Arid Meteorology, China Meteorological Administration, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province; Key Open Laboratory of Arid Climatic Change and Disaster Reduction of CMA, Lanzhou 730020, Gansu, China
  • Received:2020-06-22 Revised:2020-09-14 Online:2021-01-15 Published:2021-03-05
  • Contact: Qiang ZHANG E-mail:yanxy18@lzu.edu.cn;zhangqiang@cma.gov.cn

Abstract:

Climate change in arid areas is an important scientific issue. Based on monthly Climatic Research Unit data from 1949 to 2018, the characteristics of climate change in the Pan-Central-Asian arid region throughout the past 70 years were studied used empirical orthogonal function (EOF) and wavelet analyses. The results showed that precipitation in the Pan-Central-Asian arid area increased at the rate of 1.393 mm·(10a)-1 in the past 70 years. Precipitation in summer showed a decreasing trend, while the other three seasons showed an increasing trend, of which winter was the most obvious [0.834 mm·(10a)-1]. Winter also showed the largest temperature increase [0.360 °C·(10a)-1]. EOF analysis of precipitation anomalies shows that the precipitation anomalies in the Pan-Central-Asia arid region reflected overall consistency (the first mode of precipitation), the southwest-northeast showed reverse change characteristics (the second mode of precipitation), and west to east exhibited “-+-” alternating distribution characteristics (the third mode of precipitation). There were markedly quasi 3 a periods in all three modes, and the first mode also had quasi 5-7 a and quasi 12 a periods, while the third mode also exhibited a quasi 7 a change period. The EOF analysis of temperature anomalies showed that the temperature anomalies reflected the overall consistency (the first mode of temperature), east-west showed reverse change characteristics (the second mode of temperature), and the first mode had quasi 2 a and 8-10 a periods. At the same time, there were obvious 2-4 a and quasi 5 a cycles in the second mode. The warm season did not show a more obvious increase in the temperature and rainfall, while the cold season showed a larger increase in temperature and precipitation. Some regions presented a witting trend, such as the east and west sides of Kazakhstan, northern Xinjiang in China, and parts of the Pamir Plateau, while other places like central Kazakhstan, most of Mongolia, and Northwestern China exhibited an obvious drying trend. In general, most of Northwest China is in a weak wetting trend. With the weakening of the Asian summer monsoon, the precipitation increment in the cold season is higher than that in the warm season, which seems to indicate that the influence of the Asian winter monsoon on precipitation in the Pan-Central-Asia arid area is increasing. The research results of this paper aim to deepen the understanding of the characteristics of climate change in the Pan-Central-Asia arid region, as well as provide a scientific basis for further disaster prevention and mitigation, rational response to climate change, and sustainable development strategies.

Key words: Pan-Central-Asia arid area, EOF, wavelet analysis, changing trend