An Experience of Using the Turner Angle for Differentiating Water Structures in the Northwest Pacific

N. S. Vanin

Using the data of CTD observations in the Kuril region of the Pacific Ocean, vertical structures of water masses are analyzed and differentiated using the Turner angle Tu in the layer between the isopycnic surfaces of 26.5 and 26.8. The former characterizes the core of the cold intermediate layer in the subarctic water structure and the latter, the intermediate salinity minimum in the subtropical water structure. Vertical variations of temperature and salinity in the specified density range for subarctic and subtropical water structures are opposite to each other, and the Turner angle changes the sign from negative to positive when crossing the boundary between them. The isoline Tu = –45denotes disappearance of the cold intermediate layer, Tu = 0, an outcrop of the halocline along with the salinity front formation, and Tu = 45is the northern boundary of the subtropical water. Obtained are the relationships between the Turner angle and the variations of temperature and salinity within the mentioned layer. Demonstrated are the benefits of the proposed method for localizing the boundaries of the subarctic front as compared with traditional methods.