RAPID: Impacts of Increased Light Transmittance on Ocean Heating, Primary Productivity, and Carbon Cycling Across a Pacific Arctic Continental Shelf Gradient

RAPID：透光率增加对太平洋北极大陆架梯度的海洋加热、初级生产力和碳循环的影响

• 批准号: 2232855
• 负责人: Karen Frey
• 金额: $ 5.17万
• 依托单位: Clark University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2232855&HistoricalAwards=false
• 关键词: RAPID; Impacts; Increased; Light; Transmittance; RAPID; Impacts; Increased; Light; Transmittance

Arctic sea ice is undergoing tremendous changes. There has been a pronounced decrease in summer sea ice cover, an overall thinning of the ice, and a lengthening of the summer melt season. Some of the greatest changes in sea ice cover across the pan-Arctic have been observed in the Chukchi and Beaufort Seas surrounding Alaska, where there has been substantial loss of perennial sea ice that persists year-round (including during summer). This Pacific Arctic sector is also among the most biologically productive marine ecosystems in the world and is an important region to monitor for the flow of carbon. Although sea ice is a dominant feature in these shallow marine environments at high-latitudes, we are only beginning to understand how changes in sea ice cover (through its influence on light, seawater temperature, salinity, and nutrient availability) will affect ecosystems in these regions. In particular, earlier ice-free conditions in the spring (as well as later ice-free conditions in the fall) have disrupted the timing of algae blooms and the livelihoods of marine mammals farther up the food chain. This research is focusing upon measurements of light transmittance through the ocean water column collected at science stations during the Synoptic Arctic Survey (SAS) cruise on the US Coast Guard Ship Healy. Measurements of light transmittance through the water column will further our understanding of how light impacts heat distribution, algae growth, and carbon flows throughout the region. In addition, this project is supporting an early-career researcher and the team is contributing material for numerous undergraduate courses and partnering with the Girls Inc. organization to involve middle and high school students in opportunities to learn about Arctic Ocean science.This research is establishing new measurements of light transmittance (320–780 nm) through the uppermost ~30–50 m of the ocean water column at observation points across a continental shelf gradient (over the Chukchi Shelf into the deep Arctic Ocean basin, with the return southward over the Chukchi Borderlands). These measurements are providing the baseline knowledge necessary to understand how light availability in the water column changes spatially (across a ~2000 km long continental shelf/latitudinal gradient) as well as temporally (across a seasonal gradient from early September through late October). Using these measurements, the team is testing the hypothesis that light transmittance increases with declines in sea ice cover and varies with light absorbing impurities in the water column. The seasonal timing and geographic location of the SAS cruise provide a rare opportunity to further assess the connections of late-open-water-season light transmittance to all three research focal areas of the SAS science and implementation plan: (1) physical drivers, (2) ecosystem responses, and (3) carbon cycling.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.

北极海冰正在进行巨大的变化。夏季海冰覆盖物，冰的整体稀疏以及夏季融化季节的延长显着下降。在阿拉斯加周围的Chukchi和Beaufort海中观察到了整个泛极的海冰覆盖的一些最大变化，那里的多年生海冰全年都持续了多年生海冰（包括在夏季）。这个太平洋北极部门也是世界上生物学上最有效的海洋生态系统之一，并且是监测碳流量的重要区域。尽管海冰在这些浅水海洋环境中是一个高宽容的浅水区，但我们才开始了解海冰覆盖的变化如何（通过其对光，海水温度，盐度和养分的影响）如何影响这些地区的生态系统。特别是，春季的早期无冰条件（以及秋天的较晚的无冰条件）破坏了藻类血液的时机和海洋哺乳动物的生计，而食物链上则越来越远。这项研究的重点是通过在美国海岸警卫队船上的Symoptic Arctic调查（SAS）巡航期间通过科学站收集的海水柱进行光传输的测量。通过水柱进行光传输的测量将进一步了解光线如何影响热分布，藻类生长和整个地区的碳流。 In addition, this project is supporting an early-career researcher and the team is contributing material for numerous undergraduate courses and partnering with the Girls Inc. organization to involve middle and high school students in opportunities to learn about Arctic Ocean science.This research is establishing new measurements of light transmission (320–780 nm) through the uppermost ~30–50 m of the ocean water column at observation points across a continuoustal shelf gradient (over the Chukchi架子进入深北极海盆，向南返回Chukchi Borderlands）。这些测量值提供了必要的基线知识，以了解水柱中的光的可用性如何频繁变化（AMB 〜2000 km长的连续架子/纬度梯度）以及临时（从9月初到10月下旬的季节性梯度）。使用这些测量值，该团队正在测试以下假设：随着海冰覆盖的下降，光的传播增加，水柱中的光吸收杂质。 SAS Cruise的季节性时机和地理位置提供了一个难得的机会，可以进一步评估SAS科学和实施计划的所有三个研究焦点的晚期季节的光线传播的连接：（1）物理驱动因素，（2）生态系统的反应，以及（3）碳循环的碳循环。影响审查标准。