An Arctic Ocean sea surface pCO2, pH and O2 observing network

北冰洋海面 pCO2、pH 和 O2 观测网络

• 批准号: 1723308
• 负责人: Michael DeGrandpre
• 金额: $ 35.15万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1723308&HistoricalAwards=false
• 关键词: Arctic; Ocean; sea; surface; pCO2

Arctic Ocean sea-ice is decreasing and the water at the sea surface is getting warmer and fresher. These changes may be affecting the accumulation of carbon dioxide in the atmosphere and in the ocean. The carbon cycle is complex because there are many processes that control the amount of carbon dioxide in the Arctic Ocean. Plant growth, oxygen use by organisms, ice cover, temperature, and ocean circulation all contribute to differences in the amount of carbon dioxide in the water and the exchange of carbon dioxide with the atmosphere. As ice cover in the Arctic Ocean decreases, scientists think the water will absorb more anthropogenic (human originated) carbon dioxide from the atmosphere. As carbon dioxide levels increase, this will lead to the ocean becoming more acid (lower pH) because carbon dioxide forms carbonic acid when it dissolves in water. The lower pH water can affect the food web by slowing the growth of shell-forming organisms. Despite these important issues, not much is known about the carbon cycle in the central Arctic Ocean basins. Nearly all measurements have been made close to the Arctic coasts during the low ice summer period, when water for samples are more accessible to scientists. With this National Science Foundation support we will combine forces with another National Science Foundation project and use the Canadian icebreaker Louis S. St-Laurent to reach the under-studied central Arctic Ocean. These data will be made available to the public and other researchers. The project also supports operation of an ocean acidification exhibit for University of Montana?s science museum so we can better share our results with the public. A post-doctoral researcher, research technician, and two undergraduate students will be supported on the project. The specific activities on this project are focused on a field effort in fall 2018 that includes shipboard measurements and deployments on moorings and ice-tethered profilers. A shipboard underway partial pressure of carbon dioxide (pCO2) measurement system will be installed on the icebreaker. The goal of these measurements is to map sea surface pCO2 over a broad region to quantify air-sea CO2 fluxes. Sensors for pCO2, pH, and dissolved oxygen will be deployed on the Woods Hole Oceanographic Institution time-series moorings and ice-tethered profilers. Three moorings will be deployed with a subsurface profiler that measures conductivity, temperature, depth, and dissolved O2. Our sensors are deployed at 35 m depth, just below the subsurface float. These data are used to examine short- and long- term carbon cycle variability in the Canada Basin. Sensors for pCO2 and O2 will also be deployed just under the ice surface on two ice-tethered profilers. These sensors record variability near the ice interface that is not possible with the deeper subsurface moorings. A post-doctoral researcher will lead the data quality control and interpretation and will work with other Arctic scientists to facilitate use of the data in their studies.

北冰洋的海冰正在减少，海面的水变得越来越温暖和新鲜。这些变化可能正在影响大气和海洋中二氧化碳的积累。碳循环是复杂的，因为有许多过程控制着北冰洋中的二氧化碳含量。植物生长、生物对氧气的利用、冰盖、温度和海洋循环都会导致水中二氧化碳含量的差异以及二氧化碳与大气的交换。随着北冰洋冰盖的减少，科学家们认为，北冰洋的水将从大气中吸收更多的人为(人类起源)二氧化碳。随着二氧化碳水平的增加，这将导致海洋变得更酸(pH值更低)，因为二氧化碳在水中溶解时会形成碳酸。低pH值的水可以通过减缓贝壳形成生物的生长来影响食物网。尽管存在这些重要问题，但人们对北冰洋中部盆地的碳循环知之甚少。几乎所有的测量都是在北极海岸附近的低冰层夏季进行的，因为科学家更容易获得样本所需的水。在国家科学基金会的支持下，我们将与另一个国家科学基金会项目联合起来，使用加拿大的路易斯·圣洛朗号破冰船到达正在研究的北冰洋中部。这些数据将向公众和其他研究人员开放。该项目还支持蒙大拿大学S科学博物馆海洋酸化展览的运营，这样我们就可以更好地与公众分享我们的成果。该项目将支持一名博士后研究员、研究技术员和两名本科生。该项目的具体活动侧重于2018年秋季的实地工作，其中包括船上测量以及在系泊和冰系留剖面仪上的部署。破冰船上将安装一套船载二氧化碳分压(PCO2)测量系统。这些测量的目标是绘制广阔区域的海面二氧化碳分布图，以量化大气-海洋二氧化碳通量。二氧化碳分压、酸碱度和溶解氧传感器将部署在伍兹霍尔海洋研究所的时间序列系泊和冰系留剖面仪上。三个系泊将部署一个地下剖面仪，测量电导率、温度、深度和溶解氧。我们的传感器部署在35米深的水下浮标下方。这些数据被用来研究加拿大盆地的短期和长期碳循环变异性。二氧化碳和氧气传感器也将部署在两个冰系带剖面仪的冰面下。这些传感器记录了冰界面附近的可变性，这是更深层次的地下系泊不可能做到的。一名博士后研究员将领导数据质量控制和解释，并将与其他北极科学家合作，促进数据在他们的研究中的使用。