We find that an increase
in poleward heat transport by the tropical ocean results in a warming of the extra-tropics, relatively little change in the tropical temperatures, moistening of the subtropical dry zones, and partial but incomplete compensation of the planetary - scale energy transport by the atmosphere.
These elevated Arctic Pliocene temperatures result in a greatly reduced and asymmetrical latitudinal temperature gradient that is probably the result of
increased poleward heat transport and decreased albedo.
[Response: Part of the education has to be differentiating the factors that contribute to current climate conditions (i.e. the 33 C greenhouse effect, the
atmospheric poleward heat transport), and the things that are most likely to contribute to variations.
Changes here have a long term effect, affecting the strength of the north - ward horizontal flow of the Atlantic's upper warm layer, thereby altering the
oceanic poleward heat transport and the distribution of sea surface temperature (SST — AMO), the presumed source of the (climate) natural variability.
And no, there is no huge plunge in tropical or global surface air temperatures when the ocean circulation spins up because there is a near - compensating decrease in
poleward heat transport via the atmospheric circulation.
The conventional view on the connection between the AMOC and Arctic sea ice is that a weakening of the AMOC should reduce
ocean poleward heat transport and, hence, expand sea ice.
However, the mechanism of
increased poleward heat transport can not be the only physical mechanism driving the reduced temperature gradient because it is in fact the surface temperature gradient that ultimately drives the flux of heat poleward.
Without continents, you might not get any western boundary currents, which could alter the balance
of poleward heat transport and really affect the general circulation of the atmosphere.
A new view of the ocean emerges in which a shallow surface intensified circulation dominates
the poleward heat transport.....»
«One of the most important contributions the ocean makes to Earth's climate is through
its poleward heat transport: about 1.5 PW or more than 30 % of that accomplished by the ocean - atmosphere system (Trenberth and Caron, 2001).
Therefore, the decreased temperature gradient can be explained in part by increased
poleward heat transport, but other physical mechanisms must be invoked to explain the observed asymmetry in the latitudinal temperature gradient.
Several mechanisms have been hypothesized to explain this reduced temperature gradient, including increased
poleward heat transport, decreased ice albedo, and changes in cloud cover (Fedorov et al., 2006).
Most of the observed decline in the latitudinal temperature gradient during the Pliocene can be explained by increased
poleward heat transport.
This is one of the simplest models for the pole - to - equator surface temperature distribution and ice latitude on a spherical planet in the presence of
poleward heat transport.