** Can TIW mixing explain the discrepancy from the Sverdrup balance?**

Suppose the vorticity input by the wind is mixed meridionally by the TIW. Then the westward integration of the Sverdrup balance would integrate the curl smoothed in y. For the pressure field, the zonal integration is (1), so the quantity smoothed is dP/dx = (f²/B)Curl(Tau/f).

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

This smoothing was done centered on the (idealized) TIW region, using Gaussian-weight running means or triangle filters. The 2-dimensional Gaussian is described by 5 parameters: Amp*exp{((y-y0)/Y)²}*exp{((x-x0)/X)²}; this expression gives the width (°lat) of the triangle or running mean that was used to smooth dP/dx at each location.

- Results (P) of integration of smoothed curl (check/compare different smoothing) (all have x0=110°W, X=50°):

y0=4°N, Y=4°, RM(5) y0=4°N, Y=3°, Tr(5) y0=4°N, Y=4°, Tr(5) y0=4°N, Y=5°, Tr(5) y0=3°N, Y=5°, Tr(5) y0=3°N, Y=4°, RM(6) - All 5 smoothings compared (P)
- All 5 smoothings compared (Ug) V2 V3 V4
- Overlay meridional section at 140°E-170°E: P Ug
**End of this misguided idea**

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- Sverdrup, Geostrophic and Ekman zonal currents: 10°S-30°N 5°S-12°N
- Meridional sections in the TIW region: Curl dP/dx dP/dx to 20°N

Dots show the smoothing (averaging) applied (try different widths): 1.5°S-6.5°N V2 1.5°S-5.5°N - Result of smoothing: Curl Streamfunction Pressure Ug

See work with the Johnson CTD/ADCP data set

See work with the Sverdrup balance

See work with the Pacific Subtropical Countercurrent

Back to Kessler main figures page

Back to Kessler home page