CCE banner
 
Funded Research

Lagrangian Study of Surface Chlorophyll Variability Within Subtropical Eddies

Monger, Bruce: Cornell University (Project Lead)

Project Funding: 2009 - 2012

NRA: 2008 NASA: Ocean Biology and Biogeochemistry   

Funded by NASA

Abstract:
Subtropical mesoscale eddies have been strongly implicated as an important mechanism for nutrient delivery to the euphotic zone to fuel new primary production. One of the chief methods for studying eddy impacts on biogeochemical processes uses long-term in situ observations carried out at fix hydrostations, such as BATS, and relies on the predominately westward propagation of eddies past the observation point. Another important method of study involves relatively short-term in situ Lagrangian observations carried out while eddy movement is track through time. The first type of study lacks broad spatial coverage while the second approach is somewhat limited both in spatial and temporal coverage. Recently developed methods for automated tracking of mesoscale eddies from merged satellite altimetry data now make it possible to track thousands of mesoscale eddies that have formed in subtropical waters over the past decade. We will combine this new eddy tracking method with satellite observations of vector winds and surface chlorophyll to undertake a spatially and temporally comprehensive Lagrangian study that examines changes in surface chlorophyll in response to eddy spin-up and to variations in wind forcing within each of the thousands of individually tracked eddies. The large number of independent eddy observations will allow hypothesis testing at a high level of statistical significance. The work will provide a better understanding of the effects of eddy dynamics and wind forcing on surface chlorophyll variability and by inference variability in biological productivity. The research will provide a strong statistical test of the idea that enhanced wind stress can increase biological productivity within mode-water eddies and diminish biological productivity within cyclonic eddies. The research will also yield reliable estimates of the response time of surface chlorophyll to changes in eddy spin-up and wind forcing.


More details may be found in the following project profile(s):