N. Maximenko: Satellite ocean surface currents and windsOcean Vector Wind Working Group meeting, October 7, 2013, Boulder

1,051 active drifters (approx. 1 drifter per 4x4 degree bin; probably 30-50% are undrogued)

3659 active Argo floats (3659 / 10 days * 10 hours ≈ 152 continuous sites)

Surface currents are not well measured

Ocean Vector Wind Working Group meeting, October 7, 2013, BoulderN. Maximenko: Satellite ocean surface currents and winds

Surface currents are not well modeled

(Jim Potemra, 5th Int. Marine Debris Conference, 2011)

Why even most reputable models do not care about discrepancy with observations?

Ocean Vector Wind Working Group meeting, October 7, 2013, BoulderN. Maximenko: Satellite ocean surface currents and winds

Ekman balance: =(1/ρ) τ∙

Global circulation can be modeled without knowing surface currents

Vertically integrated Ekman transport:

I.e. forcing of subsurface ocean is not sensitive to K(z) or other mechanisms of momentum transfer between atmosphere and ocean (e.g. radiation, injection, etc.)

(Note that equations allow wind-induced surface currents to exceed surface wind.)

Having surface currents and winds measured by the same satellite would be a step toward understanding mechanical interaction in the coupled system. (The coupling starts with the correspondence between winds in the atmospheric boundary layer and currents in the ocean Ekman layer and leads to coupling in vertical motions with implications to patterns of E&P, SSS, chlorophyll, etc.)

Chelton et al. 2004, Science Yoshida et al. 2010, JGR

Xie et al. 2001, Science

Curl > 0Cyclonic eddies

Anticyclonic eddies

HLCCNEC

HLCQiu et al. 1997, JPO

← Rossby waves

Ocean Vector Wind Working Group meeting, October 7, 2013, BoulderN. Maximenko: Satellite ocean surface currents and winds

Effect of near-shore wind extends intocentral oceans

Persistent striations in long-term mean high-pass filtereddynamic ocean topography (Maximenko et al., 2008) Generation of beta-plume

High-resolution of wind, including near-shore areas,is important to study mesoscale ocean currents.