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  • Recent intensification of s...
    Zhang, Haoyue; Wu, Chuanhao; Hu, Bill X.

    International journal of climatology, 15 November 2019, Letnik: 39, Številka: 13
    Journal Article

    Ongoing climate warming is largely affecting the frequency and magnitude of short‐term climatic extremes in many regions of the world, causing significant damage to the environment and society. Here, based on the long‐term (1980–2010) meteorological observations and reanalysis products, we investigated the spatio‐temporal evolutions of short‐term concurrent hot and dry extreme (SCHDE) events over the Pearl River basin, a typical humid and subtropical basin in southern China. We also explored the physical mechanisms of SCHDE and its relationship with a series of hydrometeorological variables and large‐scale climate indices. The results indicate an intensification of SCHDE over the study basin during the study period, especially for the period 1997–2010. SCHDE occurs mostly in the northeastern and western regions and shows a statistically significant increasing trend mainly in the midwestern and southeast regions, which is mainly associated with an increased temperature (Tair), drying trend in soil moisture (SM), and a sharp increasing trend in evapotranspiration (ET). The contribution of Tair variability to the SCHDE variability is largest (57.27%), followed by SM (28.43%) and ET (14.30%). In addition to Tair, SM deficit before the onset also plays an important role in the SCHDE occurrence. Furthermore, the SCHDE variability tends to be more sensitive to the SM deficits in the high‐altitude areas than in the low‐altitude areas. Besides, wavelet transform analysis results indicate that the cold phase of ENSO tends to trigger a higher risk of SCHDE events, while El Niño Modoki events have different influences on the variations of SCHDE during different warm/cold phases over the Pearl River basin. SCHDE showed a significant increasing trend during 1997–2010. Although Tair dominates SCHDE, SM deficit before the onset also plays an important role in the SCHDE occurrence. El Niño and El Niño Modoki events had different impacts on SCHDE.