海冰覆盖度变化下北冰洋海浪研究进展

北冰洋地区海浪的生成和发展会受到海冰范围变化的显著影响。本文介绍了近年来基于浮标、潜标和走航观测,以及卫星遥感和数值模拟等方法开展的不同海冰覆盖度下北冰洋海浪的研究进展,包括海冰覆盖区海浪的传播机制等。北冰洋夏季开阔海域的平均有效波高可达3 m,在风暴期间,波弗特海有效波高可达5 m。除大西洋一侧,夏季北冰洋大部分海域海浪活动在过去几十年呈增强趋势,其中楚科奇-波弗特海有效波高增长趋势为1~3 cm/a。这一趋势主要是由海冰范围减少导致的风区增大和风暴的频率、强度增加共同导致的。基于CMIP5多模式集的预估结果显示,相比历史时期(1979—2005年),21世纪末(2081—2100年)北冰洋有效波高将以3 cm/a的速率持续增长,其中北冰洋中心地区东部海域增长最为明显。海浪活动增多会在消融期通过海浪-海冰正反馈机制促进海冰的消融。在沿岸地区,增多的海浪会加速海岸带侵蚀,促进沿岸冻土的崩解。极端海浪事件还会威胁航运安全。未来研究需基于更多的现场观测,加深对海冰范围和厚度变化影响下海浪的生成、发展、传播、衰减机制的认识,进一步提高冰区海浪模拟和预估水平。

Research progress for the changes of Arctic Ocean surface wave with diminishing sea ice

The initiation and advancement of surface waves(sea and swell) within the Arctic Ocean have been regulating by the wind forcing and the sea ice extent,which was clearly distinctive from the tropical and subtropical oceans.We present the current research advances of Arctic Ocean surface waves beneath distinctive ice coverage based on the perceptions of buoys,moorings,and ship-based measurements,as well as the studies based on satellite remote sensing and numerical simulations.The propagation mechanisms of waves in sea ice covered regions were evaluated too.The average significant wave height in the open water of the Arctic Ocean in summer can reach 3 m,and amid storms,the significant wave height can reach 5 m in the Beaufort Sea.Excluding the Atlantic division,the wave activity in the most range of the Arctic Ocean during summer has expanded within the past few decades,and the significant wave height on the Beaufort-Chukchi Sea has an expanding drift of approximately 1-3 cm/a.This trend is basically triggered by the collective impact of an increase in fetch due to the sea ice retreat,and the frequency and intensity of storms.The projection based on the CMIP5 multi-model simulations appears that compared with the historical period (1979-2005),the significant wave height over the Arctic Ocean at the end of this century (2081-2100) will increase by 3 cm/a,of which the highest increment happens within the eastern part of the central Arctic Ocean.Expanded wave movement advances the removal of through the wave-ice positive feedback mechanism during the melting period.In coastal zones,enhanced wave movement will quicken coastal erosion and promote the disintegration of coastal permafrost.Extreme waves can also pose a threat to shipping security.Future research needs to be conducted based on more and extensive field observations to deepen the understanding of the generation,development,propagation,and attenuation mechanisms of waves under the influence of changes in the sea ice extent and thickness,to progress the capacity to mimic and project waves in ice areas.