Ocean Mixed Layer Formation and Restratification Captured by High-Resolution In-Situ Observations
[26-Feb-2014] Rainville, L., Lee, C.M., Eriksen, C.C., Farrar, J.T., and Plueddemann, A.J.
Presented at the 2014 Ocean Sciences Meeting
Observations collected during the Salinity Processes Upper-ocean Regional Study (SPURS) field campaign in the subtropical North Atlantic are used to identify and quantify the processes responsible for the formation of a 100-m thick surface mixed layer in winter, and its restratification in spring and summer. An array of autonomous gliders and Argo floats complemented heavily instrumented moorings, allowing us to assess the importance of lateral gradients in the time evolution of the mixed layer. The gliders deployed during SPURS also carried temperature microstructure sensors, providing direct estimates of rates turbulent dissipation in the upper 250 m over deployments lasting several months. These direct estimates of dissipation are used to better constrain the evolution of mixed layer properties, and evaluate the impact of mixing due to internal waves and lateral intrusions at the base of the mixed layer.