Cristin-resultat-ID: 1052075
Sist endret: 19. mars 2018, 09:20
NVI-rapporteringsår: 2013
Resultat
Vitenskapelig artikkel
2013

Weakening AMOC connects Equatorial Atlantic and Pacific interannual variability

Bidragsytere:
  • Lea Svendsen
  • Nils G Kvamstø og
  • Noel Keenlyside

Tidsskrift

Climate Dynamics
ISSN 0930-7575
e-ISSN 1432-0894
NVI-nivå 2

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2013

Importkilder

Scopus-ID: 2-s2.0-84881095086

Beskrivelse Beskrivelse

Tittel

Weakening AMOC connects Equatorial Atlantic and Pacific interannual variability

Sammendrag

Observations indicate that since the 1970s Equatorial Atlantic sea surface temperature (SST) variations in boreal summer tend to modulate El Niño in the following seasons, indicating that the Atlantic Ocean can have importance for predicting the El Niño–Southern Oscillation (ENSO). The cause of the change in the recent decades remains unknown. Here we show that in the Bergen Climate Model (BCM), a freshwater forced weakening of the Atlantic meridional overturning circulation (AMOC) results in a strengthening of the relation between the Atlantic and the Pacific similar to that observed since the 1970s. During the weakening AMOC phase, SST and precipitation increase in the central Equatorial Atlantic, while the mean state of the Pacific does not change significantly. In the Equatorial Atlantic the SST variability has also increased, with a peak in variability in boreal summer. In addition, the characteristic timescales of ENSO variability is shifted towards higher frequencies. The BCM version used here is flux-adjusted, and hence Atlantic variability is realistic in contrast to in many other models. These results indicate that in the BCM a weakening AMOC can change the mean background state of the Tropical Atlantic surface conditions, enhancing Equatorial Atlantic variability, and resulting in a stronger relationship between the Tropical Atlantic and Pacific Oceans. This in turn alters the variability in the Pacific.

Bidragsytere

Lea Svendsen

  • Tilknyttet:
    Forfatter
    ved Nansen Senter for Miljø og Fjernmåling

Nils Gunnar Kvamstø

Bidragsyterens navn vises på dette resultatet som Nils G Kvamstø
  • Tilknyttet:
    Forfatter
    ved Geofysisk institutt ved Universitetet i Bergen

Noel Sebastian Keenlyside

Bidragsyterens navn vises på dette resultatet som Noel Keenlyside
  • Tilknyttet:
    Forfatter
    ved Geofysisk institutt ved Universitetet i Bergen
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