Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia.
ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, New South Wales, Australia.
Science. 2022 Nov 11;378(6620):655-659. doi: 10.1126/science.abn8657. Epub 2022 Nov 10.
Short-duration rainfall extremes can cause flash flooding with associated impacts. Previous studies of climate impacts on extreme precipitation have focused mainly on daily rain totals. Subdaily extremes are often generated in small areas that can be missed by gauge networks or satellites and are not resolved by climate models. Here, we show a robust positive trend of at least 20% per decade in subhourly extreme rainfall near Sydney, Australia, over 20 years, despite no evidence of trends at hourly or daily scales. This trend is seen consistently in storms tracked using multiple independent ground radars, is consistent with rain-gauge data, and does not appear to be associated with known natural variations. This finding suggests that subhourly rainfall extremes may be increasing substantially faster than those on more widely reported time scales.
短时间的降雨极值可能会引发暴洪，造成相关影响。先前关于气候对极端降水影响的研究主要集中在日降雨量总和上。亚日极值通常在小区域内产生，这些区域可能会被雨量计网络或卫星遗漏，也无法被气候模型所解决。在这里，我们展示了澳大利亚悉尼附近亚小时极端降雨至少每十年增加 20%的稳健趋势，尽管在小时或日尺度上没有趋势的证据。这一趋势在使用多个独立地面雷达跟踪的风暴中一致出现，与雨量计数据一致，并且似乎与已知的自然变化无关。这一发现表明，亚小时级别的降雨极值可能比那些在更广泛报道的时间尺度上的极值增加得快得多。
