A simple model is developed of the lower limb of the meridional overturning circulation in the Southern Ocean based on residual-mean theory. It is hypothesized that the strength of the lower-limb overturning ( ) is strongly controlled by the magnitude of abyssal diapycnal mixing ( ) and that of mesoscale eddy transfer (K ). In particular, it is argued that K. The scaling and associated theory f...

8 Abstract One-third of the world’s coral reefs have dis9 appeared over the last 30 years, and a further third is under 10 threat today from various stress factors. The main global 11 stress factors on coral reefs have been identified as changes 12 in sea surface temperature (SST) and changes in surface 13 seawater aragonite saturation (Xarag). Here, we use a cli14 mate model of intermediate co...

A band of enhanced thermocline variability at 108–158N in the Pacific found in nature also occurs in an ocean general circulation model forced with observed fluxes of momentum, heat, and freshwater over the period 1958– 97. The variability in the model is primarily associated with long baroclinic Rossby waves characterized by periods in the decadal range (7–10 yr). The waves are forced by westw...

We have generated a high-resolution coral D14C record from the southwest subtropical Pacific spanning the last 50 yr. Prebomb (1950–1956) D14C values average -52‰. Values begin to increase in 1957, reaching a maximum in the early 1970s, about 10 yr after the atmospheric peak. There is a consistent 10-15‰ seasonal cycle whose relationship with vertical mixing evolves as a consequence of the pene...

The thermohaline hysteresis response to varying North Atlantic freshwater forcing is studied by means of a three-dimensional global ocean general circulation model (OGCM). The influence of vertical diffusivity is examined using a wide range of mixing coefficients. For sufficiently large vertical diffusivity the model shows a pronounced hysteresis behavior, so that two equilibrium states of the ...

[1] The formation of persistent multiple fronts is an established feature of the Antarctic Circumpolar Current (ACC). Front strength and location are closely linked to eddy properties and therefore have important implications for the eddy‐driven closure of the Southern Ocean meridional overturning circulation. ACC front structure is analyzed here by calculating regional probability density func...

[1] Using an ocean general circulation model, we find that the vertical profile of the Indonesian Throughflow (ITF) transport is important in regulating the stratification and surface heat fluxes of the Indian Ocean. With the same total ITF transport, a thermocline-intensified ITF, relative to a surface-intensified ITF, not only cools the surface layer of the Indian Ocean while warming the Indi...

Global-scale tracer simulations are typically made at coarse resolution without explicitly modelling eddies. Here we ask what role do eddies play in ocean uptake, storage, and meridional transport of transient tracers. We made global anthropogenic transient-tracer simulations in coarse-resolution (2 cosφ×2, ORCA2) and eddypermitting ( 1 2 ◦ cosφ× 2 , ORCA05) versions of the ocean general circul...

Westerly wind bursts (WWBs) in the equatorial Pacific are known to play a significant role in the development of El Niño events. They have typically been treated as a purely stochastic external forcing of ENSO. Recent observations, however, show that WWB characteristics depend upon the large-scale SST field. The consequences of such a WWB modulation by SST are examined using an ocean general ci...