VERTICAL TEMPERATURE GRADIENT VARIATIONS RELATED TO CURRENT SHEAR AND TURBULENCE

• Main Author: J. R. Loveti
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Baja; Pacific; Subarctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.513.8780; http://www.aslo.org/lo/toc/vol_13/issue_1/0127.pdf

Continuous temperature profile measurements made with the NWC SVTP instrument reveal considerable structure in vertical temperature gradients, including temperature inversions. Some differences in the macrogradients in the California Current are due to dissimilarities between regions of upwelling, surface countercurrent, and current shear. Sharp small-scale gradient changes may possibly bc caused by differential currents and two-dimensional Kolmogorov turbulence generated by current shears and dynamically unstable internal waves. INTRODUCIXON All profiles taken in the California Current region with the Naval Weapons Center’s (NWC) SVTP ( sound velocity, temperature, and pressure) instrument show a definite layered structure that is due, in part, to advection from several different sources with incomplete mixing of these water masses. The California Current is a continuation of the west-wind drift, wherein part of it turns southward along the coast at about 42”-46 ” N lat depending upon the season. The sluggish current, about 700 km wide, flows south-southeast along the coast until it reaches the vicinity of the tip of Baja California, approximately 23 ” N lat, where it turns and flows westward (Sverdrup, Johnson, and Fleming 1942; Reid, Rodcn, and Wyllie 1958). The water making up the west-wind drift imparts a low surface salinity, which increases with depth, and a low surface temperature to the California Cur-rent. South of the subarctic water and west of the California Current is located the warmer and more saline eastern north Pacific central water. Horizontal mixing of this water mass with the California Current increases the salinity near the surface of the California Current creating a salinity minimum in the thermocline at a depth of