The 2017 Record Marine Heatwave in the Southwestern Atlantic Shelf
The 2017 Record Marine Heatwave in the Southwestern Atlantic Shelf
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DOI：
10.1029/2018gl081070
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发表时间：
2018-11-28
影响因子：
5.2
通讯作者：
Barreiro, M.
中科院分区：
文献类型：
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作者：
Manta, G.;de Mello, S.;Barreiro, M.
海洋热浪（MHWs）被认为是连续五天或更长时间记录的温度高于基于30年历史基线期的第90百分位数的温度，可能会产生破坏性的生态系统和社会经济后果。MHW在西南大西洋大陆架（32-38 ° S）使用1988年至2017年期间的每日海面温度进行了研究。自2014年以来，超过一半的MHWs发生了。最强烈的事件发生在2017年夏季，温度达到26.8摄氏度，比之前的最高温度高出1.7摄氏度。在区域上，一个前所未有的组合，持续极高的空气温度和低风速可能导致强烈的循环的热量获得和分层的里约拉普拉塔羽状水的影响。在高层，暴雨前大气环流波数为3，暴雨期间为阻塞型。2017年2月16日至3月9日，格兰德河（巴西）和马德普拉塔（阿根廷）之间距离海岸200公里的地区经历了过去30年海洋表面温度卫星记录中最强烈的变暖。这一异常升温被归类为海洋热浪，达到26.8摄氏度，比以前的最高温度高出1.7摄氏度，在乌拉圭首都造成鱼群死亡和有毒藻类大量繁殖，导致娱乐海滩关闭了几天。在区域范围内，持续的极高气温和低风速的前所未有的组合可能导致了强烈的热量循环和水柱的垂直分层。热带马登-朱利安振荡似乎在设置这种大气结构中发挥了主导作用。我们的研究结果强调了深入研究该地区海洋热浪的重要性，因为自2014年以来，它们变得越来越频繁。
Marine heatwaves (MHWs), considered as one when temperatures warmer than the 90th percentile based on a 30-year historical baseline period are registered for five or more consecutive days, can have devastating ecosystem and socioeconomic consequences. MHWs were studied in the Southwestern Atlantic shelf (32-38 degrees S) using daily sea surface temperatures between 1988 and 2017. More than half of the days with MHWs occurred since 2014. The most intense event happened in austral summer 2017, reaching temperatures of 26.8 degrees C, 1.7 degrees C above previous maximum. Regionally, an unprecedented combination of persistent extremely high air temperature and low wind speed probably led to an intense loop of heat gaining and stratification in the Rio de la Plata plume water's influence. At upper levels, the atmospheric circulation had a wavenumber of 3 pattern before the event and a blocking configuration during the event. Madden-Julian Oscillation seems to have played a leading role in setting this planetary scale configuration.Plain Language Summary The area between Rio Grande (Brazil) and Mar del Plata (Argentina) up to 200km off the coast experienced the most intense warming of the last 30years of sea surface temperature satellite record between 16 February and 9 March 2017. This anomalous warming, categorized as a marine heatwave, reached 26.8 degrees C, 1.7 degrees C above previous maximum and caused in the capital city of Uruguay fish mass mortalities and a toxic algae bloom, leading to the closure of recreational beaches for some days. Regionally, an unprecedented combination of persistent extremely high air temperature and low wind speed probably led to an intense loop of heat gaining and vertical stratification of the water column. The tropical Madden-Julian Oscillation seems to have played a leading role in setting this atmospheric configuration. Our results stress the importance of deepening the study of marine heatwaves in this region, as they are becoming more frequent since 2014.