Tropical Pacific influences on the North Atlantic Thermohaline Circulation

M. Latif

Abstract


Most global climate models simulate a weakening of the North Atlantic Thermohaline Circulation (THC) in
response to enhanced greenhouse warming. Both surface warming and freshening in high latitudes, the so-called
sinking region, contribute to the weakening of the THC. Some models simulate even a complete breakdown of the
THC at sufficiently strong forcing. Here results from a state-of-the-art global climate model are presented that
does not simulate a weakening of the THC in response to greenhouse warming. Large-scale air-sea interactions in
the tropics, similar to those operating during present-day El Niños, lead to anomalously high salinities in the
tropical Atlantic. These are advected into the sinking region, thereby increasing the surface density and compensating
the effects of the local warming and freshening. The results of the model study are corroborated by the analysis of
observations.

Keywords


thermohaline circulation;air-sea

Full Text:

PDF

References


DOI: https://doi.org/10.4401/ag-3392

Published by INGV, Istituto Nazionale di Geofisica e Vulcanologia - ISSN: 2037-416X