scholarly journals The Relationship Between U.S. East Coast Sea Level and the Atlantic Meridional Overturning Circulation: A Review

2019 ◽  
Vol 124 (9) ◽  
pp. 6435-6458 ◽  
Author(s):  
Christopher M. Little ◽  
Aixue Hu ◽  
Chris W. Hughes ◽  
Gerard D. McCarthy ◽  
Christopher G. Piecuch ◽  
...  
Keyword(s):  
Sea Level ◽  
East Coast ◽  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Overturning Circulation ◽  
Meridional Overturning ◽  
The Relationship

scholarly journals Regional Patterns of Sea Level Change Related to Interannual Variability and Multidecadal Trends in the Atlantic Meridional Overturning Circulation*

2010 ◽  
Vol 23 (15) ◽  
pp. 4243-4254 ◽  
Author(s):  
K. Lorbacher ◽  
J. Dengg ◽  
C. W. Böning ◽  
A. Biastoch
Keyword(s):  
Sea Level ◽  
Time Scales ◽  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Global Ocean ◽  
Overturning Circulation ◽  
Regional Patterns ◽  
Model Experiments ◽  
Basin Scale ◽  
Meridional Overturning

Abstract Some studies of ocean climate model experiments suggest that regional changes in dynamic sea level could provide a valuable indicator of trends in the strength of the Atlantic meridional overturning circulation (MOC). This paper describes the use of a sequence of global ocean–ice model experiments to show that the diagnosed patterns of sea surface height (SSH) anomalies associated with changes in the MOC in the North Atlantic (NA) depend critically on the time scales of interest. Model hindcast simulations for 1958–2004 reproduce the observed pattern of SSH variability with extrema occurring along the Gulf Stream (GS) and in the subpolar gyre (SPG), but they also show that the pattern is primarily related to the wind-driven variability of MOC and gyre circulation on interannual time scales; it is reflected also in the leading EOF of SSH variability over the NA Ocean, as described in previous studies. The pattern, however, is not useful as a “fingerprint” of longer-term changes in the MOC: as shown with a companion experiment, a multidecadal, gradual decline in the MOC [of 5 Sv (1 Sv ≡ 106 m3 s−1) over 5 decades] induces a much broader, basin-scale SSH rise over the mid-to-high-latitude NA, with amplitudes of 20 cm. The detectability of such a trend is low along the GS since low-frequency SSH changes are effectively masked here by strong variability on shorter time scales. More favorable signal-to-noise ratios are found in the SPG and the eastern NA, where a MOC trend of 0.1 Sv yr−1 would leave a significant imprint in SSH already after about 20 years.

scholarly journals Sediment <sup>231</sup>Pa/<sup>230</sup>Th as a recorder of the rate of the Atlantic meridional overturning circulation: insights from a 2-D model

2009 ◽  
Vol 6 (3) ◽  
pp. 2755-2829 ◽  
Author(s):  
Y. Luo ◽  
R. Francois ◽  
S. E. Allen
Keyword(s):  
Circulation Model ◽  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Equatorial Atlantic ◽  
Overturning Circulation ◽  
Data Set ◽  
The North ◽  
Meridional Overturning ◽  
The Relationship ◽  
D Model

Abstract. A two dimensional scavenging-circulation model is used to investigate the patterns of sediment 231Pa/230Th generated by the Atlantic Meridional Overturning Circulation (AMOC) and further advance the application of this proxy for ocean paleocirculation studies. The scavenging parameters and the geometry of the overturning circulation cell have been chosen so that the model generates meridional sections of dissolved 230Th and 231Pa consistent with published water column profiles and an additional 12 previously unpublished profiles measured in the North and Equatorial Atlantic. The processes that generate the meridional sections of dissolved and particulate 230Th, dissolved and particulate 231Pa, dissolved and particulate 231Pa/230Th, and sediment 231Pa/230Th are discussed in detail. The results indicate that the relationship between sediment 231Pa/230Th at any given site and the overturning circulation is very complex. They clearly show that constraining past changes in the strength and geometry of the AMOC requires an extensive data set and they suggest strategies to maximize information from a limited number of samples.

scholarly journals How is New England Coastal Sea Level Related to the Atlantic Meridional Overturning Circulation at 26° N?

2019 ◽  
Vol 46 (10) ◽  
pp. 5351-5360 ◽  
Author(s):  
Christopher G. Piecuch ◽  
Sönke Dangendorf ◽  
Glen G. Gawarkiewicz ◽  
Christopher M. Little ◽  
Rui M. Ponte ◽  
...  
Keyword(s):  
New England ◽  
Sea Level ◽  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Overturning Circulation ◽  
Coastal Sea ◽  
Meridional Overturning

scholarly journals On the Path of the Gulf Stream and the Atlantic Meridional Overturning Circulation

2010 ◽  
Vol 23 (11) ◽  
pp. 3146-3154 ◽  
Author(s):  
Terrence M. Joyce ◽  
Rong Zhang
Keyword(s):  
Gulf Stream ◽  
Climate Model ◽  
Numerical Models ◽  
Internal Variability ◽  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Overturning Circulation ◽  
Meridional Overturning ◽  
The Relationship ◽  
Ocean Observations

Abstract The Atlantic meridional overturning circulation (AMOC) simulated in various ocean-only and coupled atmosphere–ocean numerical models often varies in time because of either forced or internal variability. The path of the Gulf Stream (GS) is one diagnostic variable that seems to be sensitive to the amplitude of the AMOC, yet previous modeling studies show a diametrically opposed relationship between the two variables. In this note this issue is revisited, bringing together ocean observations and comparisons with the GFDL Climate Model version 2.1 (CM2.1), both of which suggest a more southerly (northerly) GS path when the AMOC is relatively strong (weak). Also shown are some examples of possible diagnostics to compare various models and observations on the relationship between shifts in GS path and changes in AMOC strength in future studies.

scholarly journals Twentieth century Atlantic meridional overturning circulation as an indicator of global ocean multidecadal variability: influences on sea level anomalies and small pelagic fishery synchronies

2013 ◽  
Vol 71 (3) ◽  
pp. 455-468
Author(s):  
Daniel Kamykowski
Keyword(s):  
Sea Level ◽  
Mesoscale Eddies ◽  
Atlantic Meridional Overturning Circulation ◽  
Planetary Waves ◽  
Meridional Overturning Circulation ◽  
Boundary Current ◽  
Overturning Circulation ◽  
Sea Level Anomalies ◽  
Meridional Overturning ◽  
Pelagic Fishery

Abstract The Atlantic dipole phosphate utilization (ADPU) index, derived through statistical conversion of 20th century Atlantic basin subpolar sea surface temperatures, is used as a fingerprint of Atlantic meridional overturning circulation (AMOC) variability and as an indicator of global Meridional Overturing Circulation (MOC) variability. ADPU index correlations with differences in sea level anomalies (SLAs) between Canada and the UK and across the Isthmus of Panama demonstrate intrabasin and interbasin associations with MOC variability. Cross-correlation analyses of ADPU index, SLAs, and sardine (S) and anchovy (A) catch differences [S −A] (normalized sardine catch minus normalized anchovy catch) confirm strong correlations between ADPU and [S −A] off Japan, California, Peru and Southwest Africa (Benguela). Statistically significant cross correlations also exist between the ADPU index and SLAs for Japan, California, Peru and Benguela, and for SLAs and [S − A] for Japan, California and Peru, but the short time-series lengths compared with the length of the multidecadal cycle limit the interpretation of the observed lead-lags. Though correlation is not causality, the correlation analyses developed here are useful in support of hypothesis generation. The proposed hypothesis to explain the observed small pelagic fishery synchronies asserts: (i) ocean bathymetry and continental distributions interact with multidecadal variations in MOC strength that occur along the conceptual global conveyor belt to generate changes in global oceanic planetary waves and mesoscale eddies that propagate through the world ocean; (ii) each small pelagic fishery region has a unique spatial relationship with pertinent oceanic planetary wave and mesoscale eddy source regions that affect the timing and strength of the waves and eddies that influence the nearby boundary current; (iii) synchronous changes or phasing among global fisheries depend on how and when MOC variability mediated by oceanic planetary waves and mesoscale eddies reaches each fishery region; (iv) oceanic planetary waves and/or mesoscale eddies influence the strength or meandering of the boundary current adjacent to a small pelagic fishery region to change local SLAs and environmental conditions to favour sardine or anchovy populations at different times.

scholarly journals Sediment <sup>231</sup>Pa/<sup>230</sup>Th as a recorder of the rate of the Atlantic meridional overturning circulation: insights from a 2-D model

Ocean Science ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 381-400 ◽  
Author(s):  
Y. Luo ◽  
R. Francois ◽  
S. E. Allen
Keyword(s):  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Equatorial Atlantic ◽  
Overturning Circulation ◽  
Data Set ◽  
The North ◽  
Circulation Cell ◽  
Meridional Overturning ◽  
The Relationship ◽  
D Model

Abstract. A two dimensional scavenging model is used to investigate the patterns of sediment 231Pa/230Th generated by the Atlantic Meridional Overturning Circulation (AMOC) and further advance the application of this proxy for ocean paleocirculation studies. The scavenging parameters and the geometry of the overturning circulation cell have been chosen so that the model generates meridional sections of dissolved 230Th and 231Pa consistent with published water column profiles and an additional 12 previously unpublished profiles measured in the North and Equatorial Atlantic. The processes that generate the meridional sections of dissolved and particulate 230Th, dissolved and particulate 231Pa, dissolved and particulate 231Pa/230Th, and sediment 231Pa/230Th are discussed in detail. The results indicate that the relationship between sediment 231Pa/230Th at any given site and the overturning circulation is very complex. They clearly show that constraining past changes in the strength and geometry of the AMOC requires an extensive data set and they suggest strategies to maximize information from a limited number of samples.

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