Spatial and temporal variability of compound drought heatwave events in the Northern Hemisphere

Recent decades have witnessed a notable increase in the compound drought and heatwave events (CDHW) in many regions across the globe, which may have more complex and intense implications on terrestrial ecosystem stability than individual extreme events.  It is necessary to clarify the response of terrestrial ecosystems to compound drought-heatwave events. However, the research is remain poorly understood about this. Therefore, we used the Standardized Precipitation Index (SPI) and temperature data to extract the regions where occur compound drought and heatwave events in global. The results obtained in this study are as follows: Firstly, the majority of the regions that have experienced compound drought heatwaves have experienced only one such event, while only a small percentage have experienced two such events. Secondly, we found that the number of compound drought heatwave events in all years is generally more in drylands than in wetlands.