Kuroshio Current Eddies Joshua Coupe Kuroshio Current western

Kuroshio Current Eddies Joshua Coupe

Kuroshio Current → western boundary current of the North Pacific → meanders break off when barotropic/baroclinic processes make the flow too turbulent → ultimately a way to release energy Qiu, 2001

Temperature (Celsius) -images generated using GLORYS 2 V 1 global ocean model reanalysis

What does an eddy look like? An eddy falls into two categories in the northern hemisphere: Cyclonic (cold) and Anticylonic (warm) eddies → Anticyclonic eddies advect warm water into colder regions (propagate west) → Cyclonic eddies advect cold water into warmer regions (propagate southwest) Eddies are identifiable through distinct characteristics. . .

Anticyclonic Eddies Cyclonic Eddies

What does an eddy look like? An eddy falls into two categories in the northern hemisphere: Cyclonic (cold) and Anticylonic (warm) eddies → Anticyclonic eddies advect warm water into colder regions (propagate northwest) → Cyclonic eddies advect cold water into warmer regions (propagate southwest) ✓ ✓

Seasonal Variability

Why detect and track eddies? → Biological importance → productivity on periphery of warm-core eddies [Hitchcock et al. 1985] → cold-core eddies productive throughout -much higher surface chlorophyll, 50% higher productivity [Ring Group, 1981] and [Kimura, 1997]

References Hitchcock, G. , Langdon, C. , Smayda, T. 1985. Short-term changes in the biology of a Gulf Stream warm-core ring: Phytoplankton biomass and productivity, Oceanography, 32, 919 -928. The Ring Group, 1981, Gulf Stream Cold-Core Rings: Their Physics, Chemistry, and Biology, American Association for the Advancement of Science, 212, 4499, 1091 -1100. → because Gulf Stream eddies are a great analog for Kuroshio Current eddies Kimura, S. , Kasai, A. , Nakata, H. , Sugimoto, T. , Simpson, J. , Cheok, J. , 1997, Biological productivity of meso-scale eddies caused by frontal disturbances in the Kuroshio, ICSE Journal of Marine Science, 54, 179 -192. Qiu, B. 2001. Kuroshio and Oyashio Currents, Academic Press, 1413 -1422. Kang, D. , and E. N. Curchitser, 2013: Gulf Stream eddy characteristics in a high-resolution ocean model. J. Geophys. Res. Oceans, 118, 4474– 4487, doi: 10. 1002/jgrc. 20318.