DEFIANT: Drivers and Effects of Fluctuations in sea Ice in the ANTarctic

挑战：南极海冰波动的驱动因素和影响

• 批准号: NE/W004755/1
• 负责人: James Hosking
• 金额: $ 28.42万
• 依托单位: The Alan Turing Institute
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW004755%2F1
• 关键词: DEFIANT; Drivers; Effects; Fluctuations; sea

Since the start of the industrial revolution the CO2 concentration in the atmosphere has steadily risen. Scientists have confirmed that the recent loss of Arctic sea ice in summer directly follows this rise in human-induced CO2 emissions, reducing from about 7 million km2 of Arctic sea ice in the late 1970s to around 3.5 million km2 in the 2010s.While climate models suggest Antarctic sea ice extent should also reduce in response to rising CO2, satellite observations reveal that during 1979-2015 the opposite was in fact true. The trend in Antarctic sea ice extent has been a small increase of approximately 1.5% per decade. In 2016, however, this increase was abruptly interrupted by a dramatic reduction in sea ice extent that was far outside the previously observed range. Since the extreme event in 2016, Antarctic sea ice extent has almost returned to its pre-2016 values, highlighting the significant variability in Antarctic sea ice conditions that can occur from one year to the next. These variations in sea ice are important to the whole Earth's climate, because they affect the melting of the glacial Antarctic Ice Sheet, and the capture of atmospheric heat and CO2 by the Southern Ocean.The recent extreme swings in Antarctic sea ice extent, and the challenge of accurately predicting, understanding and modelling them, emphasise the need to: (i) increase our knowledge of the processes that drive Antarctic sea ice variations, including extreme events, and (ii) understand the drivers and climate implications of Antarctic sea ice loss over different time-scales, from weeks to decades. To address this knowledge gap requires a significant research programme, one that takes year-round observations, including throughout the harsh Antarctic winter, and is effective in improving the underlying processes in the latest computer climate models.Our project, known as DEFIANT (Drivers and Effects of Fluctuations in sea Ice in the ANTarctic), will embark on one of the most ambitious observational campaigns aimed at understanding Antarctic sea ice variability. Scientific measurements from the German research ship Polarstern, the UK's new polar research ship Sir David Attenborough, the British Antarctic Survey's Rothera research station, aircraft overflights and satellites will work seamlessly together with cutting-edge robotic technologies (including the underwater vehicle Boaty McBoatface and a suite of on-ice buoys) to provide us with comprehensive, year-round measurements of atmosphere, sea ice and ocean. The knowledge gained from these observations will enable our team to develop new ocean and climate models in order to more accurately represent Antarctic sea ice processes.The analysis of these improved models will allow us to better understand the underlying drivers of the sudden decrease in Antarctic sea ice, determine the impact of these extreme events on the global ocean circulation, and forecast the implications for the movements of heat and CO2 through the climate system. By developing new observations, new satellite records, and new models, DEFIANT will deliver a major advance in our understanding of the Antarctic sea ice system and its wider impacts on global climate.

自工业革命开始以来，大气中的二氧化碳浓度稳步上升。科学家们已经证实，最近夏季北极海冰的消失直接伴随着人类引起的二氧化碳排放量的增加，北极海冰的面积从 20 世纪 70 年代末的约 700 万平方公里减少到 2010 年代的约 350 万平方公里。卫星观测显示，1979 年至 2015 年期间，事实恰恰相反。南极海冰范围的趋势是每十年小幅增加约 1.5%。然而，2016 年，这种增长突然被海冰范围急剧减少所中断，远远超出了之前观察到的范围。自 2016 年极端事件以来，南极海冰范围几乎已恢复到 2016 年之前的水平，凸显了南极海冰状况在一年与下一年之间可能发生的显着变化。海冰的这些变化对整个地球的气候很重要，因为它们影响南极​​冰盖的融化，以及南大洋对大气热量和二氧化碳的捕获。最近南极海冰范围的极端波动，以及准确预测、理解和建模它们的挑战，强调需要：（i）增加我们对驱动南极海冰变化的过程（包括极端事件）的了解，以及（ii）了解南极海冰消失的驱动因素和气候影响超过不同的时间尺度，从几周到几十年。为了解决这一知识差距，需要一项重大的研究计划，该计划需要全年观测，包括整个南极洲的严酷冬季，并能有效改进最新计算机气候模型的基础过程。我们的项目被称为 DEFIANT（驱动程序和南极海冰波动的影响）将开展一项最雄心勃勃的观测活动，旨在了解南极海冰的变化。德国科考船 Polarstern、英国新型极地科考船 David Attenborough 爵士、英国南极调查局的 Rothera 研究站、飞机飞越和卫星的科学测量将与尖端机器人技术（包括水下航行器 Boaty McBoatface 和一套冰上浮标）为我们提供大气、海冰和海洋的全年全面测量。从这些观测中获得的知识将使我们的团队能够开发新的海洋和气候模型，以便更准确地表示南极海冰过程。对这些改进模型的分析将使我们能够更好地了解南极海面积突然减少的潜在驱动因素确定这些极端事件对全球海洋环流的影响，并预测对气候系统中热量和二氧化碳运动的影响。通过开发新的观测结果、新的卫星记录和新模型，DEFIANT 将在我们对南极海冰系统及其对全球气候的更广泛影响的理解方面取得重大进展。

项目成果

Interrogating Sea Ice Predictability with Gradients

用梯度询问海冰的可预测性

• DOI: http://dx.10.1109/lgrs.2024.3366308
• 发表时间: 2024
• 期刊: IEEE Geoscience and Remote Sensing Letters
• 影响因子: 4.8
• 作者: Joakimsen H

Sea ice detection using concurrent multispectral and synthetic aperture radar imagery

使用并发多光谱和合成孔径雷达图像进行海冰探测

• DOI: 10.48550/arxiv.2401.06009
• 发表时间: 2024-01-11
• 期刊: ArXiv
• 作者: Martin S J Rogers;Maria Fox;Andrew Fleming;Louisa van Zeel;Jeremy Wilkinson;J. S. Hosking
• 通讯作者: J. S. Hosking