On the uncertainty of future projections of Marine Heatwave events in the North Atlantic Ocean

Plecha Sandra M.; Soares Pedro M. M.; Silva-Fernandes Susana M.; Cabos William

摘要

Marine Heatwave (MHW) events have been increasing all around the world, causing severe impacts on marine ecosystems and on the economy of the aquaculture, fishing and tourism industries. In this study, the occurrence and characteristics of MHW events in the North Atlantic are analyzed for a recent period (1971-2000) and the two future periods (2041-2070 and 2071-2100). The analysis is based on Sea Surface Temperature (SST) data obtained from observations and from Global Climate Models (GCM) in the CMIP5 archieve. The results show that the GCMs present significant shortcomings in reproducing the SST and MHWs. The model results regarding the recent trends in MHW are in agreement with the ones observed, although they underestimate the values of MHW intensity and overestimate the values of both frequency and duration of events. The MHWs observed occur at a mean frequency of 1.90 events per year and are characterized by similar to 13 days of mean duration and 0.37 degrees C of mean intensity, while the multi-model ensemble mean characterizes the events with 12 additional days and 0.15 degrees C less intensity. Under climate change scenarios, when considering a stationary threshold, the models project noticeable increases in MHW event intensity that could reach 2 degrees degrees C above the 90th percentile and a quasi-permanent state of MHW by the end of the century. When a non-stationary threshold is considered, the characteristics of the events are similar to those obtained during the historical period. The GCMs significant biases in simulating the SST and leading to extremes like MHWs highlight the importance of improving GCM performance.

机译：海洋热浪（MHW）活动一直在全球越来越多，对海洋生态系统和水产养殖，渔业和旅游业的经济造成严重影响。在这项研究中，北大西洋中MHW事件的发生和特征是在最近（1971-2000）和两个未来时期（2041-2070和2071-2100）分析。分析基于从观察结果和来自CMIP5 Archieve中的全球气候模型（GCM）获得的海表面温度（SST）数据。结果表明，GCMS在再现SST和MHW方面存在显着的缺点。关于MHW最近趋势的模型结果与观察到的趋势同意，尽管它们低估了MHW强度的值并高估了频率和事件持续时间的值。观察到的MHWS每年的平均频率发生1.90个事件，其特征在于类似于23天的平均持续时间和0.37度的平均强度，而多模型集合均值具有12天和0.15度的事件表征事件强度较少。在气候变化场景下，在考虑静止的阈值时，模型项目明显增加MHW事件强度，可以达到90百分点的2度高于90百分点和世纪末的准永久状态。当考虑非稳定性阈值时，事件的特征类似于历史时期中获得的特性。在模拟SST并导致极端的GCMS显着偏差突出了改善GCM性能的重要性。

On the uncertainty of future projections of Marine Heatwave events in the North Atlantic Ocean

摘要

著录项

相关主题

期刊订阅