Deep Pacific Circulation Controlled by Vertical Diffusivity at the Lower Thermocline Depths

Deep-reaching thermocline mixing in the equatorial pacific cold tongue

Vertical mixing is an important factor in determining the temperature, sharpness and depth of the equatorial Pacific thermocline, which are critical to the development of El Ninõ and Southern Oscillation (ENSO). Yet, properties, dynamical causes and large-scale impacts of vertical mixing in the thermocline are much less understood than that nearer the surface. Here, based on Argo float and the ...

Pacific thermocline bridge revisited

The coupling on decadal time scales of the midlatitude and tropical Pacific via an oceanic 'bridge' in the thermocline is investigated using ocean general circulation model hindcasts and a coupled ocean atmosphere model. Results indicate that in the tropics decadal anomalies of isopycnal depth are forced by Ekman pumping and are largely independent of the arrival of subducted anomalies in the t...

A Westward-Intensified Decadal Change in the North Pacific Thermocline and Gyre-Scale Circulation

From the early 1970s to the mid-1980s, the main thermocline of the subarctic gyre of the North Pacific Ocean shoaled with temperatures at 200–400-m depth cooling by 18–48C over the region. The gyre-scale structure of the shoaling is quasi-stationary and intensified in the western part of the basin north of 308N, suggesting concurrent changes in gyre-scale transport. A similar quasi-stationary c...

The Lower Depths

Synchronous deglacial thermocline and deep-water ventilation in the eastern equatorial Pacific

The deep ocean is most likely the primary source of the radiocarbon-depleted CO2 released to the atmosphere during the last deglaciation. While there are well-documented millennial scale Δ14C changes during the most recent deglaciation, most marine records lack the resolution needed to identify more rapid ventilation events. Furthermore, potential age model problems with marine Δ14C records may...