Auad, G., J. P. Kennett and A. J. Miller, 2003:

The North Pacific Intermediate Water response to a modern climate shift

Journal of Geophysical Research,108, 3349, doi:10.1029/2003JC001987.

Abstract. Oceanic observations and an isopycnal ocean model simulation are used to investigate the response of North Pacific Intermediate Water (NPIW) to atmospheric forcing associated with the well known 1976-77 climate regime shift to a warm regime. The model reproduces numerous features of NPIW including distribution, depth, temperature and salinity. Changes in NPIW associated with the climate shift in the California coastal region were strongly influenced by an anomalous poleward flow at depth (300-1100m). This current transports old, high salinity, low oxygen intermediate waters from the northern tropics to the midlatitudes. For depths below the mixed layer, the model reproduces observed changes in salinity, nitrates and to some extent oxygen, thus suggesting that advective/diffusive processes are dominant in determining their concentrations below 300m, isolated from the surface effects of direct atmospheric forcing and biological processes. These changes are structurally similar to those induced by much larger, abrupt climate changes at the end of the last glacial episode.

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