Extremes of diurnal temperature range in karst regions: Definition, trends and interaction with wind speed

Abstract

Diurnal temperature range (DTR) is an important climate indicator that exerts substantial effects on society as well as the environment, particularly on karst landforms where the ecosystem is vulnerable and sensitive to DTR. However, the space-time pattern of extremes of DTR and their relationship with wind speed over global karst regions remain poorly understood. In this study, we defined DTR extremes and investigated the spatiotemporal patterns of warm-season extremes and their relationships with wind speeds across global karst regions during 1980–2022. Our results reveal that arid zones such as the Middle East and northwestern China exhibit large long-term mean DTR and DTR extremes. There is an increase in the frequency of DTR extremes for most regions, though pronounced regional divergence of DTR trends exists. The intensity of DTR extremes show apparent increasing trends in North America and Europe, but in other regions decreased trends are prevailing. For most regions worldwide, declining wind speed trends are discerned, though slight increases are observed in the western United States. Moreover, wind speed is generally strengthened along with larger DTR. Daytime DTR extremes dominate North America, Europe and south China, while nighttime extremes are likely to occur in the Middle East and Asia. These findings advance the understanding of DTR extremes in fragile karst ecosystems, which could help for region-specific climate adaptation strategies.