Program and Agenda

Abstract

UPPER OCEAN MIXING OBSERVATIONS DURING TACE: MIXING PROCESSES IN THE EQUATORIAL ATLANTIC VS. PACIFIC

While elevated mixing in the upper thermocline of the equatorial Pacific and its dominant role in the mixed layer temperature balance is known since 1985, only a single cruise focused on upper ocean turbulence measurements in the equatorial Atlantic prior to TACE. In the TACE period, a extensive shipboard microstructure measurement program was carried out during 10 cruises to the Atlantic cold tongue region between 23°W and Sao Tome Island (6.5°E). The data set was complemented by measurements from autonomous microstructure platforms during the later cruises. The cruises were scheduled in different seasons resolving seasonal variability of mixing processes. Similarly to the equatorial Pacific, upper thermocline turbulence in the equatorial Atlantic is strongly elevated, particularly during the boreal summer period when the Atlantic cold tongue forms. Shear instability within the zonal equatorial current system is the main energy source sustaining the energetic turbulence but meridional shear from intraseasonal variability also contributes. Although levels of turbulent dissipation rates in the equatorial Atlantic are comparable to those in the Pacific, night time enhancement of the turbulent bursts is much less pronounced in the Atlantic.

Authors

Dengler, M., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, mdengler@geomar.de

Hummels, R., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, rhummels@geomar.de

Brandt, P., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, pbrandt@geomar.de

Fischer, T., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, tfischer@geomar.de

Krahmann, G., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, gkrahmann@geomar.de

Details

Oral presentation

Session #:159
Date: 2/26/2014
Time: 14:30
Location: 311

Presentation is given by student: No