U.S.-Australia Cooperative Research: Biogeochemical Processes in the Subantarctic Zone

9724919南大洋亚南极地区在过去和现在的全球气候变化中都发挥着关键作用，因此引起了国际科学界的极大兴趣。该提案寻求资金支持与澳大利亚海洋科学家的独特合作，以研究这一海洋区域的生物地球化学循环。查尔斯顿大学地质学系的首席研究员贾科莫·迪图利奥教授和塔斯马尼亚大学南极和南大洋环境合作研究中心的彼得·N·塞德威克博士将对整个微生物群落的生理状态和对铁和主要营养物质限制生长的反应进行跨学科研究。实验将研究铁可能通过生物群控制硅：氮利用率的可能性(包括对物种优势的影响)，对铁的异养/自养竞争，以及铁对辐射重要气体二甲基硫化物(DMS)及其前体DMSP生产的主要营养影响。澳大利亚南极光号船上的实地项目和研究巡航将包括澳大利亚、新西兰和法国的研究人员，以及该项目支持的美国研究人员。这些成果将有助于我们了解影响全球碳循环的因素，并将进一步交流思想，鼓励美国、新西兰、法国和澳大利亚海洋科学界之间的合作。

9724919 DiTullio The Subantarctic Zone of the Southern Ocean plays a critical role in both past and present global climate change, and is therefore of considerable interest to the international science community. This proposal seeks funds to support a unique collaboration with Australian marine scientists to investigate biogeochemical cycling in this oceanic region. The prinicipal investigator, Professor Giacomo Di Tullio, of the Department of Geology, University of Charleston, and his counterpart, Dr. Peter N. Sedwick, of the Cooperative Research Center for the Antarctic and Southern Ocean Environment, University of Tasmania, will conduct and interdisciplinary study of the physiological status and response of the whole microbial community to growth limitation by iron and major nutrients. Experiments will examine the possibility that iron may control Si:N utilization ratios by the biotas (including implications for species dominance), heterotrophic/autotrophic competition for iron, and iron and major nutrient effects on production of the radiatively important gas dimethylsulfide (DMS) and its precursor DMSP. The field program and research cruise on the Australian vessel RSV Aurora Australis will involve Australian, New Zealand, and French researchers as well as the American researchers supported under this project. Results will contribute to our understanding of factors affecting global carbon cycling, and will further the exchange of ideas and encourage cooperation between the marine science communities of the United States, New Zealand, France, and Australia.