Circulation at the Entrance to the Gulf of California

学术价值：2013年4月，在南极洲帕尔默站返回加利福尼亚州莫斯·兰丁的过程中，将对加利福尼亚州海湾入海口水域进行为期8天的调查。将使用从海洋表面延伸到海底的近距离CTD观测以及使用船载声学多普勒海流剖面仪对海流的观测来测量太平洋和加利福尼亚州海湾之间的流速和输送。将在下加利福尼亚州南部海岸进行类似的观测，以确定加利福尼亚州海湾形成的水到达太平洋时的命运。这些观测将补充墨西哥恩塞纳达的下加利福尼亚自治大学(UABC)和加利福尼亚州蒙特利的海军研究生院(NPS)联合开展的一项为期20年的观测计划。墨西哥湾入海口的表层水生产力很高，部分原因是海湾水和太平洋水混合在一起，而次表层水的溶解氧很少，约为每公斤2-4微摩尔。后者令人担忧，因为沿着下加利福尼亚州流出墨西哥湾的地下水加入了加州暗流，并沿着美国西海岸向极地流动，这可能是南加州海湾氧气值下降的原因之一。2013年对墨西哥湾入海口水域性质的观测将与1991年的观测结果进行比较，以了解水体性质是否随着时间的推移而发生系统变化。更广泛的影响：这项合作研究将为UABC的研究生和本科教学项目以及NPS的研究生项目做出贡献。学生将参与船上数据的收集、处理和解释。该项目还将促进与墨西哥海洋学家继续合作进行海洋研究，这对于了解共同海洋资源的联合管理是必要的。这些例子包括当低氧水流入大陆架时出现的“死区”，以及洪堡鱿鱼向北迁移到加州水域时发生的生态扰动。所有收集的数据将提交给国家海洋数据中心(NODC)存档和分发。

Intellectual merit: An eight-day survey of waters at the mouth of the Gulf of California will be conducted during the return transit of R/V Point Sur from Palmer Station, Antarctica, to Moss Landing, California, in April 2013. Flow rates and transports between the Pacific Ocean and Gulf of California will be measured using closely spaced CTD observations which extend from the ocean surface to the bottom as well as from observations of currents using vessel mounted acoustic Doppler current profilers. Similar observations will be carried out along the southern coast of Baja California in order to determine the fate of waters formed in the Gulf of California when they reach the Pacific Ocean. These observations will complement a 20-year program of observations carried out jointly by the Universidad Autonoma de Baja California (UABC) in Ensenada, Mexico, and the Naval Postgraduate School (NPS) in Monterey, CA. Surface waters at the mouth of the Gulf are highly productive, in part due to mixing of Gulf and Pacific waters, while subsurface waters contain very little dissolved oxygen, about 2-4 micro mole per kg. The latter is of concern as subsurface waters which flow out of the Gulf along Baja California join the California Undercurrent and flow poleward along the West Coast of the United States, perhaps contributing to declining oxygen values in the Southern California bight. 2013 observations of water properties at the mouth of the Gulf will be compared to those obtained in 1991 to see if systematic changes of water properties are occurring with time. Broader impacts: This collaborative research will contribute to graduate and undergraduate teaching programs at UABC and graduate programs at NPS. Students will be involved with collection, processing, and interpretation of shipboard data. The project will also foster continued cooperative ocean studies with Mexican oceanographers which are necessary to understand joint management of common ocean resources. Examples include "dead zones" which occur when low oxygen waters flow onto the continental shelf and the ecological perturbations which occur when Humboldt squid move northward into California waters. All the collected data will be submitted to the National Oceanographic Data Center (NODC) for archiving and distribution.