A better understanding of recent changes of the CO2 system in the Western Arctic Ocean via field measurements from the summer 2014 CHINARE cruise

该项目将延续中美两国科学家在研究大气与北冰洋表层水之间二氧化碳交换方面的成功合作。它包括收集高分辨率的pCO2（二氧化碳分压）数据，并结合2014年夏季中国北极科考（CHINARE）巡航期间的水柱pH、总溶解无机碳（DIC）、碱度、钙、营养物质和氧气的离散样本。结合历史数据，这些结果将用于约束海面二氧化碳分压、空气-海洋二氧化碳通量的变化及其随时间的变化，并了解北冰洋西部潜在的碳循环控制机制。研究者假设：1)北冰洋西部海面二氧化碳分压变化很大，受气候敏感的多个参数控制，目前的知识不足以得出关于海气二氧化碳通量、控制机制和未来变化预测的可靠结论；2)随着海冰的退缩，高生物生产（和CO2/DIC去除）区域已从20世纪90年代和21世纪初的南部地区扩展到今天的北部盆地；3)河流无机碳和有机碳输入增加，它们在控制北冰洋西部海面pCO2和海气净CO2交换通量方面发挥重要作用。该项目将继续开展积极的国际合作，并通过实地考察和数据综合活动培养中国北极碳研究团队。这项合作将把这些数据整合到几个美国和国际数据库中。该项目还将直接支持一名博士生。

This project would continue a successful collaboration between U.S. and Chinese scientists to study the exchange of carbon dioxide between the atmosphere and the surface waters of the Arctic Ocean. It involves the collection of high resolution underway pCO2 (partial pressure of carbon dioxide) data combined with discrete samples of water column pH, total dissolved inorganic carbon (DIC), alkalinity, calcium, nutrients, and oxygen during the Chinese Arctic Research Expedition (CHINARE) cruise in summer 2014. Together with historical data, the results will be used to constrain the variability of sea surface pCO2, air-to-sea CO2 flux, and their changes over time and to understand the underlying carbon cycling control mechanisms in the Western Arctic Ocean. The investigator hypothesizes that 1) sea surface pCO2 is highly variable in the Western Arctic Ocean and is controlled by multiple parameters that are climate-sensitive, and that current knowledge is insufficient to draw reliable conclusions regarding air-sea CO2 flux, controlling mechanisms and prediction of future changes, 2) high biological production (and CO2/DIC removal) areas have expanded from the southern areas in 1990s and early 2000s to the northern basins today along with the retreat of sea ice, and 3) riverine inorganic and organic carbon inputs have increased and they play an important role in controlling sea surface pCO2 and thus the net air-sea CO2 exchange flux in the western Arctic Ocean. This project would continue an active international collaboration and culture a Chinese Arctic carbon research team through fieldwork and data synthesis activities. The collaboration would incorporate these data into several U.S. and international databases. The project would also directly support a Ph.D. student.