Arid Zone Research ›› 2024, Vol. 41 ›› Issue (11): 1797-1807.doi: 10.13866/j.azr.2024.11.01

• Weather and Climate • Previous Articles     Next Articles

Division index of early or late and length grade in climate seasons in Xizang

SHI Jiqing1,2(), LUO Suxuan3, ZHANG Weihua1, ZHOU Kanshe1(), HU Jie1, ZHANG Dongdong1, GAN Chenlong4   

  1. 1. Xizang Climate Center, Lhasa 850000, Xizang, China
    2. Xigazê National Climate Oberservatory, Xigazê 857000, Xizang, China
    3. Xizang Meteorological Disaster Prevention Technology Center, Lhasa 850000, Xizang, China
    4. Maizhokunggar County Meteological Bureau, Lhasa 850000, Xizang, China
  • Received:2024-06-03 Revised:2024-08-09 Online:2024-11-15 Published:2024-11-29
  • Contact: ZHOU Kanshe E-mail:shijiqing10@126.com;zhoukanshe@163.com

Abstract:

To better understand the response mechanisms of seasonal changes in high-altitude areas to ecological and environmental factors amid global climate change, it is crucial to study the indicators of seasonal early or late and length grade duration classification in Xizang. In this study, we analyzed daily temperature data from 38 meteorological stations in Xizang (1981-2023) using temperature thresholds of 6 ℃, 17 ℃, 17 ℃ and 6 ℃ for four seasons, to explore the classification indices and evolution laws of seasonal early or late and length grade. The results revealed the following: (1) The average start dates for spring, summer, autumn, and winter at the 38 stations were April 21, June 17, July 17, and October 17, with average lengths of 56 d, 29 d, 92 d, and 188 d, respectively. (2) The start and end times, as well as the lengths of the climatic seasons, exhibit characteristics of minimum standard deviation in winter and maximum standard deviation in summer. (3) The start dates, end dates, and length of the climatic seasons, as well as the start and end times and length of the four seasons, showed the following patterns: Normal>slightly early (late) and early (late)>significantly early (late) and abnormally early (late). A indicator is more in line with the threshold of the classification indicators of early or late and length grade. (4) In Xizang, the onset of spring and summer trends was earlier, while autumn and winter had late trends. (5) The start date of spring, the end date of winter, and the length of summer across the 38 stations were primarily classified as normal, whereas the start dates of summer, autumn, and winter, along with the end dates of spring and autumn, were mainly categorized as early. Conversely, the lengths of spring and autumn were mainly classified as short, while winter was predominantly classified as long, and the end date of summer was primarily considered late. These findings provide valuable insights into climate resource management, ecological protection, and the overall impact on human production and life.

Key words: climate season, early or late and length grade, standard deviation, evolution law, Xizang