Langmuir circulation (LC) in the upper ocean mixed layer (UOML) is a feature most familiarly observed as linear stripes or sea surface streaks approximately parallel to the wind direction. These result from helical (ovoid) water cells rotating clockwise and anticlockwise, forming alternating bands of convergence (downwelling) and divergence (upwelling) at the surface. Windspeed determines the depth and the spacings of these circulation cells. As a driver of surface renewal in the UOML, LC may then be responsible for processes such as divergence zone capture and transport of phytoplankton upwards to the surface and the convergence zone collection and sinking of surfactants and transferable gases into the water column.
Investigators from the University of South Florida and the Smithsonian Research Center wish to extend numerical modeling studies of the effects of LC on two topics of interest to Antarctic oceanography, firstly, a) photoinhibition of the primary productivity of phytoplankton under Antarctic summer light fields (including effects of surface UV penetration) and possibly, b) parameterizations of sea-air gas exchange. Two recent field data sets including productivity studies in the Ross Sea polyna and the Southern Ocean Gas Experiment (SO-GasEx) will form the basis for comparisons of field data with fine scale numerical computations of LC effects using large-eddy simulations (LES).
"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."
