b0=0 b0>0

2p + [(2*H*b0)/(d*|f0|)] ∂xp + [2/d] f0/|f0| ∂yt(x) = 0

Sverdrup interior

Stommel boundary

-p(x,y)t(x)

Vorticity:

f+ x = const.fconst

xconst

fconst

xconstf+ x = const.f+

x-

f-

x+

f-plane: b-plane:

Vorticity tendencies due to1. Planetary b-effect:

Vorticity tendencies due to2. Wind-stress Curl:

Vorticity tendencies due to3. Friction:

Total vorticity tendencies:

f+ x = const.f+

x-

f-

x+

West East

-1.0 (-9.0) +1.0 (+0.9)

-1.0 (-1.0) -1.0 (-1.0)

+0.1 (+10) +0.1 (+0.1)

-1.9 (0.0) +0.1 (0.0)

Stommel, H., 1951: An elementary explanation of why ocean currents are strongest in the West, BAMS, 32, 21-23.

Modeled Sea Surface Temperature

Gulfstream

http://science.hq.nasa.gov/oceans/physical/OSC.html

http://www.atmos.washington.edu/~hakim/542/barotropic.html

Barotropic Instability of a Shear Flow (Gaussian Strip of Vorticity):

y

x