Majeed Haris, Coles John G, Moore G W K
Institute of Medical Sciences University of Toronto Toronto Ontario Canada.
Division of Cardiovascular Surgery The Hospital for Sick Children Toronto, Ontario Canada.
Geohealth. 2020 Feb 3;4(2):e2019GH000220. doi: 10.1029/2019GH000220. eCollection 2020 Feb.
The frequency and magnitude of extreme summer temperature events in the United States have increased in the past few decades. Long-term exposure to extreme summer temperatures can be detrimental to human health, due to potential risks of dehydration and thermoregulation strains on the cardiovascular system, which may often lead to heat-related mortality (HRM). The summer climate of the United States is influenced by variability in Atlantic and Pacific sea surface temperatures, driven in part by Atlantic Multidecadal Oscillation (AMO) and El-Nino Southern Oscillation (ENSO), respectively. However, the influence of AMO and ENSO on HRM in the United States has not been investigated. Here the longest time series of HRM spanning the past five decades is analyzed in relation with AMO and ENSO. We find that HRM doubled in the early-1990s, coinciding with the positive phase of the AMO. Furthermore, we note a positive association between the variability in HRM and summer temperatures across all regions of the United States, with the strongest association found over the Southern United States. Therefore, this research suggests that variability in Atlantic and Pacific sea surface temperatures has both a nationwide and regional impact on HRM in the United States. Hence, by understanding variability in sea surface temperatures, the future burden of heat-attributed emergencies during extreme summer temperature events can be reduced not only for the United States, but also worldwide.
在过去几十年中，美国极端夏季温度事件的频率和强度有所增加。长期暴露在极端夏季温度下可能对人类健康有害，因为存在脱水风险以及心血管系统的体温调节压力，这可能经常导致与热相关的死亡率（HRM）。美国的夏季气候受到大西洋和太平洋海表温度变化的影响，部分分别由大西洋多年代际振荡（AMO）和厄尔尼诺 - 南方涛动（ENSO）驱动。然而，AMO和ENSO对美国HRM的影响尚未得到研究。在此，我们分析了过去五十年来最长的HRM时间序列与AMO和ENSO的关系。我们发现，在20世纪90年代初，HRM增加了一倍，这与AMO的正相位相吻合。此外，我们注意到美国所有地区的HRM变化与夏季温度之间存在正相关，在美国南部发现的相关性最强。因此，这项研究表明，大西洋和太平洋海表温度的变化对美国的HRM具有全国性和区域性影响。因此，通过了解海表温度的变化，不仅可以减轻美国，而且可以减轻全球极端夏季温度事件期间与热相关的紧急情况的未来负担。
