Synthesizing historical records to constrain and understand Great Sea Ice Anomalies

综合历史记录来限制和理解大海冰异常

• 批准号: 2127861
• 负责人: Martin Miles
• 金额: $ 27.22万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-01 至 2024-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2127861&HistoricalAwards=false
• 关键词: Synthesizing; historical; records; constrain; understand

Arctic sea ice is not just a passive indicator of climate change, but also an active agent of change. Interactions between sea ice, oceans, and the atmosphere affect the global climate system in ways that are not yet fully understood. This project focuses on understanding how sudden changes in the export of sea ice (Great Sea Ice Anomalies or GSIAs) from the Arctic Ocean through Fram Strait (between Svalbard and Greenland) and along the East Greenland Current can have far-reaching and long-lasting effects in the subpolar North Atlantic. For example, in the 1960s and 1970s, a large and abrupt influx of sea ice and freshwater from the Arctic Ocean led to a strong anomaly in the salinity of the northern Atlantic Ocean (what has become known as the Great Salinity Anomaly). There are indications that such GSIA events have occurred in the past, but the frequency, intensity, and causes of such events are not yet understood. The research team is assembling data from historical and cultural records dating back to 1600 to identify potential anomalies and combining these results with advanced modelling results to understand potential triggers of GSIAs and how their occurrence affects the North Atlantic. This study will investigate abrupt GSIAs in the Atlantic Arctic using multiple lines of evidence based on data from long observational time series, historical, and proxy records of sea ice spanning several centuries in the waters near southwestern Greenland, northern Iceland, and the western Nordic Seas. These data will provide an empirical foundation required to assess the occurrence and origins of GSIAs and explore three hypotheses: (1) GSIAs of decadal to multidecadal duration are recurrent events, with the (sub)decadal sea ice anomaly leading to the 1960–70s salinity anomaly being a moderate realization; (2) GSIAs can be initiated spontaneously from natural internal climate-system variability alone; and (3) sea ice anomalies east of Greenland and multidecadal variability in Atlantic Ocean sea-surface temperatures are coupled bidirectionally. The research will provide the first-ever consistent catalog of GSIAs and improve our fundamental understanding of how abrupt changes in sea ice in the Atlantic Arctic occur. The research will provide important historical perspectives and contribute to a better understanding of changes in the Arctic system. This research has broad scientific importance because abrupt changes in sea ice export may influence ocean circulation and temperatures, marine ecosystems, and climate across the northern North Atlantic.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

北极海冰不仅是气候变化的被动指标，也是变化的主动因素。海冰、海洋和大气之间的相互作用以尚未完全理解的方式影响着全球气候系统。该项目的重点是了解从北冰洋通过弗拉姆海峡（斯瓦尔巴和格陵兰之间）和沿着东格陵兰海流输出海冰（大海冰异常或GSIAs）的突然变化如何对北大西洋副极地产生深远和持久的影响。例如，在20世纪60年代和70年代，北冰洋的海冰和淡水突然大量涌入，导致北方大西洋的盐度出现强烈异常（即所谓的大盐度异常）。 有迹象表明，这种GSIA事件在过去发生过，但这种事件的频率，强度和原因尚不清楚。 该研究小组正在收集可追溯到1600年的历史和文化记录中的数据，以确定潜在的异常，并将这些结果与先进的建模结果相结合，以了解GSIAs的潜在触发因素及其发生如何影响北大西洋。这项研究将调查突然GSIAs在大西洋北极地区使用多线的证据，从长期观测的时间序列，历史和代理记录的海冰跨越几个世纪的数据在格陵兰岛西南部附近的沃茨，北方冰岛和北欧西部海域。这些资料将为评估GSIAs的发生和起源提供必要的经验基础，并探讨三种假设：（1）持续时间为十年到几十年的GSIAs是周期性事件，（亚）十年海冰异常导致1960- 70年代的盐度异常是一种适度的实现：（2）GSIAs可以仅由自然内部气候系统变率自发启动;格陵兰以东海冰异常与大西洋海温的年代际变化存在双向耦合。这项研究将提供有史以来第一个一致的GSIAs目录，并提高我们对大西洋北极海冰突变如何发生的基本理解。这项研究将提供重要的历史视角，并有助于更好地了解北极系统的变化。这项研究具有广泛的科学意义，因为海冰出口的突然变化可能会影响整个北大西洋北方的海洋环流和温度，海洋生态系统和气候。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。