Interdecadal Variation of Spring Extreme High-Temperature Events in the Western Tianshan Mountains and Its Relationship with the Tropical SST

• Published in: Advances in meteorology 2023-06, Vol.2023, p.1-13
• Main Authors: Ma, Liyun, Chen, Ping, Yao, Junqiang, Hu, Jinggao, Mao, Weiyi
• Format: Article
• Language: English
• Subjects: Agricultural production; Air-sea interaction; Analysis; Atmospheric circulation; Atmospheric waves; Climate change; Cloud cover; El Nino; Enthalpy; Floods; Fluctuations; Frequency variation; Heat; Heat flux; Heat transfer; High temperature; Humidity; Ice; Mountains; Ocean-atmosphere interaction; Radiation; Radiation flux; Regions; Rivers; Sea surface; Sea surface temperature; Sensible heat; Sensible heat flux; Sensible heat transfer; Short wave radiation; Solar radiation; Surface temperature; Temperature (air-sea); Temperature rise; Trends; Walker circulation; Water circulation; Water vapor; Water vapor content; Water vapour; Wave trains
• ISSN: 1687-9309; 1687-9317
• DOI: 10.1155/2023/3560009

This study performed an observational analysis to examine the interdecadal variation in the frequency of extreme high-temperature events (EHEs) during spring over the western Tianshan mountain, China, which were characterized by relatively fewer (more) EHEs during 1983–1996 (2000–2015). A composite analysis indicated that the interdecadal increase in EHEs is closely related to a deep dynamic anomalous Iranian high. Under the control of this high system, the water vapor content decreased over the western Tianshan mountains, and atmospheric circulation was dominated by a descending motion. Both were attributed to the decreased cloud cover, inducing a cloud-forced net solar radiation increase. The short-wave radiation flux and sensible heat flux reaching the surface increased, and the net surface heat flux increased cumulatively, which was conducive to the surface temperature increase and EHE occurrence. The anomalous Iranian high responsible for ECEs occurrence was related to the air-sea interaction over the Atlantic and Indo-Pacific. The latitudinal sea surface temperature (SST) difference between the tropical western Pacific and the western Indian Ocean directly strengthens the Walker circulation and thus enhances the Iranian high. In addition, the anomalous Iranian high was affected by the atmospheric wave trains at middle latitude, which was triggered by the warm anomaly of the Atlantic SST.