Seasonal decay and break-up of sea ice in the Arctic coastal domain

北极沿海地区海冰的季节性衰退和破裂

• 批准号: RGPIN-2020-05329
• 负责人: Ehn, Jens
• 金额: $ 1.82万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=717595
• 关键词: Seasonal; decay; break; up; sea

The decline of Arctic sea ice is one of the most prominent signals of climate change on Earth. Particularly the thick, multiyear ice is in rapid decline, indicating that the state of the Arctic Ocean is undergoing a shift towards a seasonal sea ice regime with new emerging open water areas. The landfast ice fringing the shores freezes up later, breaks up earlier, and is generally becoming less safe. Coastal communities around the Arctic have raised concern as they depend on the stability of the landfast ice for their subsistence hunting and travel. Less sea ice and more open water allows sunlight to heat the ocean and melt ice more rapidly, resulting in more open water this is the well-known ice-albedo feedback loop. The Arctic Ocean is also receiving more freshwater from river runoff, glacier meltwater and precipitation. Thus, the Arctic marine environment is becoming both warmer and fresher, and the reduction in sea ice is linked to increased storminess, coastal erosion and permafrost melt. My research involves fieldwork in Arctic coastal communities, in ice camps, or onboard ships to observe and better understand the processes and climate feedbacks that control the seasonal and interannual change of Arctic sea ice. The focus of this research program is on the seasonally sea ice covered coastal and nearshore environment, or the so-called costal domain. The research objectives are to investigate: 1) the interplay between the components of the surface energy balance and the melt progression of the sea ice; 2) how ice melting affects the propagation of sunlight through the sea ice into the water column; and 3) how the seasonal decay and breakup of sea ice in the coastal and nearshore zone has changed over the last decades as a function of thermal decay (i.e., objectives 1 and 2) and external influences from the adjacent terrestrial (warm air advection, impurities, freshwater runoff) and marine domains (oceanic heat, waves, tides, storm surges). With these objectives, I will tackle phenomena that are at the heart of understanding the changing Arctic coastal sea ice environment, which is of particular concern to local residents and land users. Our ability to predict how the marine- and climate system in the Arctic will change, and how ecosystems will respond, rests on understanding the interactions between the sea ice, the ocean and the surrounding terrestrial system. The three objectives of this research program are interrelated, and as such designed as collaborative yet distinct individual projects for 6 PhD, 4 MSc and 5 BSc students. The outcome of this research will advance our knowledge of sea ice processes and climate feedbacks in the new emerging state of the Arctic Ocean, train students in Arctic marine research, involve northern residents in the research, and ultimately, benefit Northerners by improving climate predictions and process understanding that will help communities and various levels of government adapt to climate change.

北极海冰的减少是地球上气候变化最显著的信号之一。特别是厚的多年冰正在迅速减少，这表明北冰洋的状态正在向季节性海冰状态转变，出现了新的开放水域。海岸边缘的陆地冰冻结得更晚，破裂得更早，而且通常变得更不安全。北极周围的沿海社区已经引起了人们的关注，因为他们依靠陆地冰的稳定性来维持生计，狩猎和旅行。更少的海冰和更多的开阔水域允许阳光加热海洋，更快地融化冰，导致更多的开阔水域这就是众所周知的冰反照率反馈回路。北冰洋也从河流径流、冰川融水和降水中吸收了更多的淡水。因此，北极海洋环境正在变得更加温暖和新鲜，海冰的减少与风暴增加、海岸侵蚀和永久冻土融化有关。