Increase in the number of explosive low‒level cyclones around King George Island in the last three decades.
Increase in the number of explosive low‒level cyclones around King George Island in the last three decades.
复制标题
过去三十年来，乔治王岛周围爆发性低空气旋的数量有所增加。
DOI：
10.1590/0001-3765202220210633
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Marcelo B Rosa
中科院分区：
文献类型：
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作者：
A. Setzer;M. Kayano;Marcelo R. Oliveira;W. L. Cerón;Marcelo B Rosa
本文记录了1989-2020年期间在南极南设得兰群岛乔治王岛观测到的爆发性气旋(EC)数量的增加。在纬度60度的ECS中，地面气压在24小时内下降了24百帕(≥)。年际EC频率时间序列显示出2.7个气旋/十年的显著正向趋势，2003年出现突变，突变前后的平均事件数分别为7.3和11.8次。这一上升遵循了早些时候记录在案的1981-2018年期间全球海洋表面温度(SST)的异常趋势，部分原因是全球变暖和太平洋年代际涛动(PDO)。EC频率和SST之间的联系可能是通过东南太平洋和西南大西洋SST的变化而发生的，异常寒冷的条件有利于EC的增加。我们还发现，同时发生PDO和大西洋年代际振荡的ECs的数量存在着密切的反位相关系，2003年后分别处于冷相和暖相，2003年前则相反。这两种低频模式似乎都调节了内皮细胞的数量。据作者所知，这些结果以前从未讨论过，可能会对气候建模研究和天气预报有所帮助。
This paper documents an increase in the number of observed explosive cyclones (EC) at King George Island, South Shetland Islands, Antarctica, over the 1989‒2020 period. In ECs at 60o latitudes the surface atmospheric pressure drops ≥24 hPA in 24 hours. The annual EC frequency time series shows a significant positive trend of ~2.7 cyclones/decade, with a break in 2003 and average numbers of 7.3 and 11.8 events before and after that break, respectively. The increase follows closely earlier documented global sea surface temperature (SST) anomaly trends for the 1981‒2018 period, partially attributed to global warming and to the Pacific Decadal Oscillation (PDO). Connections between EC frequency and SST might occur through variations in SST in the southeastern Pacific and southwestern Atlantic, with anomalous cold conditions favoring an increase in ECs. We also found close relations between the number of ECs with simultaneous occurrences of PDO and Atlantic multidecadal oscillation in opposite phases, so that after 2003 they were in the cold and warm phases, respectively, and vice-versa before 2003. Both low-frequency modes seem to modulate the number of ECs. As per the authors knowledge these results have not been discussed before and may help climate modeling studies and weather forecasts.