P. Gaube and D.J. McGillicuddy, Jr.
The Influence of Gulf Stream Eddies and Meanders on Near-Surface Chlorophyll.
Deep Sea Research I, 2017 doi: 10.1016/j.dsr.2017.02.006 [PDF]
Summary: The trends in chlorophyll (CHL) in both cyclonic and anticyclonic eddies forming north and south of the Gulf Stream are analyzed from satellite observations and physical – biological simulations. While cyclonic eddies present a surplus of CHL compared to their ambient south of the Gulf Stream, anticyclones present a deficit on its northern side. This deficit is seen to reduce over time and model simulation highlight the combination of surface stress and surface current generating Ekman pumping, and hence upwelling, as a mechanism responsible for the observed increase in CHL.
P. Gaube, C. Barcelo, D.J. McGillicuddy, Jr, A. Domingo, P. Miller, B. Giffoni, N. Marcovaldi, and Y. Swimmer
The Use of Mesoscale Eddies by Juvenile Loggerhead Sea Turtles (Caretta carreta) in the Southwestern Atlantic.
Plos One, 2017 doi:10.1371/journal.pone.0172839 [PDF]
Summary: The trajectories of young loggerhead sea turtles is compared to the location of eddies in the Brazil-Malvinas confluence zone east of Argentina and Uruguay in the southwestern Atlantic Ocean. The marine animals are found to prefer anticyclonic eddies by both increasing their presence in their interior and slowing their swimming speeds, possibly to improve their chance of finding food.
H. Song, J. Marshall, P. Gaube, and D.J. McGillicuddy, Jr.
Anomalous Anthropogenic Gas Uptake by Mesoscale Eddies in the Southern Ocean
Journal of Geophysical Research: Oceans, 2015 doi:10.1002/2014JC010292 [PDF]
Summary: Mesoscale eddies can modulate air-sea fluxes of heat and gases by featuring different water properties than their surroundings. Modeling of Chlorofluorocarbon-11 (CFC-11) in an eddy-resolving global model is used to understand the role of eddies in ventilating the ocean by modifying mixed layer depth dynamics. In the Southern Ocean, anticyclonic, warm core eddies decrease the partial pressure of CFC-11 (pCFC-11) in the mixed layer, thereby increasing its uptake from the atmosphere. Conversely, cyclonic, cold core eddies increase pCFC-11 leading to a decrease in atmospheric uptake.
P. Gaube, D.B. Chelton, R.M. Samelson, M.G. Schlax, and L.W. O’Neill
Satellite Observations of Mesoscale Eddy-Induced Ekman Pumping
Journal of Physical Oceanography, 2015 doi:10.1175/JPO-D-14-0032.1 [PDF]
Summary: Three mechanisms are known to cause Ekman pumping inside eddies: the interaction between surface wind stress and ocean current, the interaction between surface stress and surface current vorticity gradient, and the curl of stress generated by the SST anomalies that eddies represent compared to their ambient. In most regions Ekman pumping resulting from wind and surface current interactions dominate compared to that generated by SST anomalies. Near western boundary currents and the Antarctic Circumpolar Current however, all three mechanisms are of similar contribution to the observed Ekman pumping velocities.
P. Gaube, D.J. McGillicuddy Jr., D.B. Chelton, M.J. Behrenfeld and P. G. Strutton
Regional Variations in the Influence of Mesoscale Eddies on Near-Surface Chlorophyll
Journal of Geophysical Research – Oceans, 2014 doi:10.1002/2014JC010111 [PDF]
Summary: A global overview of eddies influence on chlorophyll (CHL) is provided by analyzing satellite measurement of ocean color. In western boundary current regions cyclonic eddies feature a positive CHL anomaly and conversely for anticyclones as high- or low-CHL water is respectively trapped during eddy formation. In the southern Indian Ocean however, cyclonic eddies displayed a negative CHL anomaly and anticyclone displayed a positive CHL anomaly due to the eddy-induced change in stratification.
P. Gaube, D. B. Chelton, P. G. Strutton, and M.J. Behrenfeld
Satellite Observations of Chlorophyll, Phytoplankton Biomass and Ekman Pumping in Nonlinear Mesoscale Eddies
Journal of Geophysical Research – Oceans, 2013 doi:10.1002/2013JC009027 [PDF]
Summary: From nine years of satellite data including sea surface height, wind stress, and chlorophyll-a concentration, the role of eddy-induced Ekman pumping is emphasized as a mechanism involved in the maintenance of the positive chlorophyll anomalies found in anticyclones in the southern Indian Ocean.
Satellite Observations of the Influence of Mesoscale Ocean Eddies on Near-Surface Temperature, Phytoplankton and Surface Stress
Ph.D Thesis (Oregon State University), 2012 [PDF]
D. B. Chelton, P. Gaube, M. G. Schlax, J. J. Early, and R. M. Samelson
The Influence of Nonlinear Mesoscale Eddies on Near-Surface Chlorophyll
Science, 2011 doi:10.1126/science.1208897 [PDF]
Summary: Ten years of satellite measurements of sea surface height and ocean color reveal a strong correlation between trends in chlorophyll concentration and the presence of eddies. On time scales longer than two weeks it was shown that the advection of chlorophyll by horizontal velocities associated with eddies was the predominant mechanism responsible for chlorophyll changes.
L.A. Hurtado, M. Freey, P. Gaube, and T.A. Markow
Geographical Subdivision, Demographic History And Gene Flow In Two Sympatric Species Of Intertidal Snails, Nerita Funiculata and Nerita Scabricosta, from The Tropical Eastern Pacific
Marine Biology, 2007 [PDF]