Frequency- or amplitude-dependent effects of the Atlantic meridional overturning on the tropical Pacific Ocean

Abstract. Using the ECHAM5/MPI-OM model, we study the relation between the variations in the Atlantic meridional overturning circulation (AMOC) and both the Pacific sea surface temperature (SST) and the El Niño-Southern Oscillation (ENSO) amplitude. In a 17-member 20C3M/SRES-A1b ensemble for 1950–2100 the Pacific response to AMOC variations on different time scales and amplitudes is considered. The Pacific response to AMOC variations associated with the Atlantic Multidecadal Oscillation (AMO) is very small. In a 5-member hosing ensemble where the AMOC collapses due to a large freshwater anomaly, the Pacific SST response is large and in agreement with previous work. Our results show that the modelled connection between AMOC and ENSO depends very strongly on the frequency and/or the modelled amplitude of the AMOC variations. Interannual AMOC variations, decadal AMOC variations and an AMOC collapse lead to entirely different responses in the Pacific Ocean.

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Frequency-dependent effects of the Atlantic meridional overturning on the tropical Pacific Ocean

Ocean Science Discussions ◽

10.5194/osd-6-477-2009 ◽

2009 ◽

Vol 6 (1) ◽

pp. 477-490 ◽

Cited By ~ 1

Author(s):

L. A. te Raa ◽

G. J. van Oldenborgh ◽

H. A. Dijkstra ◽

S. Y. Philip

Keyword(s):

Pacific Ocean ◽

Southern Oscillation ◽

Atlantic Multidecadal Oscillation ◽

Meridional Overturning Circulation ◽

Sea Surface ◽

Tropical Pacific Ocean ◽

The Pacific ◽

Meridional Overturning ◽

The Pacific Ocean ◽

The Tropical Pacific

Abstract. Using the ECHAM5/MPI-OM model, we study the relation between the variations in the Atlantic meridional overturning circulation (AMOC) and both the Pacific sea surface temperature (SST) and the El Niño-Southern Oscillation (ENSO) amplitude. In a 17-member 20C3M/SRES-A1b ensemble for 1950–2100 the Pacific response to AMOC variations on different time scales and amplitudes is considered. The Pacific response to AMOC variations associated with the Atlantic Multidecadal Oscillation (AMO) is very small. In a 5-member hosing ensemble where the AMOC collapses due to a large freshwater anomaly, the Pacific SST response is large and in agreement with previous work. Our results show that the modelled connection between AMOC and ENSO depends very strongly on the frequency and/or the amplitude of the AMOC variations. Interannual AMOC variations, decadal AMOC variations and an AMOC collapse lead to with entirely different responses in the Pacific Ocean.

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Linear trends in sea surface temperature of the tropical Pacific Ocean and implications for the El Niño-Southern Oscillation

Climate Dynamics ◽

10.1007/s00382-012-1331-2 ◽

2012 ◽

Vol 40 (5-6) ◽

pp. 1223-1236 ◽

Cited By ~ 68

Author(s):

Michelle L. L’Heureux ◽

Dan C. Collins ◽

Zeng-Zhen Hu

Keyword(s):

Pacific Ocean ◽

Surface Temperature ◽

Sea Surface Temperature ◽

El Nino ◽

Southern Oscillation ◽

Tropical Pacific ◽

Sea Surface ◽

Tropical Pacific Ocean ◽

Linear Trends ◽

The Tropical Pacific

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Numerical study of the meridional overturning circulation with “mixing hotspots” in the Pacific Ocean

Journal of Oceanography ◽

10.1007/s10872-006-0050-x ◽

2006 ◽

Vol 62 (3) ◽

pp. 259-266 ◽

Cited By ~ 4

Author(s):

Takahiro Endoh ◽

Toshiyuki Hibiya

Keyword(s):

Pacific Ocean ◽

Numerical Study ◽

Meridional Overturning Circulation ◽

Overturning Circulation ◽

The Pacific ◽

Meridional Overturning ◽

The Pacific Ocean

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Effects of the Pacific Diapycnal Mixing and Wind Stress on the Global and Pacific Meridional Overturning Circulation*

Journal of Physical Oceanography ◽

10.1175/jpo2792.1 ◽

2005 ◽

Vol 35 (10) ◽

pp. 1876-1890 ◽

Cited By ~ 10

Author(s):

Ryo Furue ◽

Masahiro Endoh

Keyword(s):

Wind Stress ◽

North Atlantic ◽

Meridional Overturning Circulation ◽

Sea Surface ◽

Overturning Circulation ◽

The North ◽

Vertical Diffusivity ◽

The Pacific ◽

Meridional Overturning ◽

The Pacific Ocean

Abstract Numerical experiments are conducted using an idealized basin to investigate roles of the deep vertical diffusivity and wind stress of the Pacific Ocean in the global and Pacific meridional overturning circulation. The Pacific middepth diffusivity is found to be enhancing the global meridional overturning circulation; when this part of diffusivity is reduced to the background value, not only is the layered circulation of the Pacific greatly weakened, but also the production of the North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) is significantly reduced. The deeper part of the Pacific diffusivity is found to be enhancing the production of the AABW in the model. When the wind stress is turned off in the Pacific, the deep meridional overturning circulation of the Pacific is reduced and the production of the NADW and AABW is also significantly reduced. This is likely due to the reduction of the wind-enhanced upwelling in the subpolar and equatorial regions. These results suggest the importance of the diapycnal diffusion and sea surface conditions in the Pacific not only to the circulation within the Pacific but also to the global meridional overturning circulation.

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