Subannual to Interannual Variabilities of SST in the North Atlantic Ocean

AbstractBased on observational data, this work examines the multi-time-scale feature of the sea surface temperature (SST) variability averaged in the whole North Atlantic Ocean (to be referred to as NASST), as well as its time-scale-dependent connections with El Niño–Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). Traditionally, the NASST index is used to characterize the SST trend and multidecadal variability in the North Atlantic. This study found that superimposed on a prominent long-term trend, NASST is nonnegligible at subannual and interannual time scales, compared with that at decadal to multidecadal time scales. Spatially, the interannual variation of NASST is characterized by a horseshoe-like pattern of the SST anomaly (SSTA) in the North Atlantic. It is mainly a lagged response to ENSO through the atmospheric bridge, and NAO plays a secondary role. At the subannual time scale, both ENSO and NAO play a role in generating the fluctuations of NASST and a horseshoe-like pattern in the North Atlantic. Nevertheless, both the ENSO- and NAO-driven variations only explain a small fraction of the variances in both the interannual and subannual time scales. Thus, other factors unrelated to ENSO or NAO may play a more important role. The associated thermodynamical processes are similar at the two time scales; however, the dynamical processes have a significant contribution to the subannual component, but not to the interannual component. Thus, the SSTA averaged in the North Atlantic as a whole varies at different time scales and is associated with different mechanisms.

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Multi-decadal uptake of carbon dioxide into subtropical mode water of the North Atlantic Ocean

Biogeosciences Discussions ◽

10.5194/bgd-8-12451-2011 ◽

2011 ◽

Vol 8 (6) ◽

pp. 12451-12476 ◽

Cited By ~ 4

Author(s):

N. R. Bates

Keyword(s):

Carbon Dioxide ◽

Atlantic Ocean ◽

North Atlantic ◽

North Atlantic Ocean ◽

Dissolved Inorganic Carbon ◽

Mode Water ◽

Subtropical Mode Water ◽

The North ◽

The North Atlantic ◽

The North Atlantic Oscillation

Abstract. Natural climate variability impacts the multi-decadal uptake of anthropogenic carbon dioxide (Cant) into the North Atlantic Ocean subpolar and subtropical gyres. Previous studies have shown that there is significant uptake of CO2 into the subtropical mode water (STMW) that forms south of the Gulf Stream in winter and constitutes the dominant upper-ocean water mass in the subtropical gyre of the North Atlantic Ocean. Observations at the Bermuda Atlantic Time-series Study (BATS) site near Bermuda show an increase in dissolved inorganic carbon (DIC) of +1.51 ± 0.08 μmol kg−1 yr−1 between 1988 and 2011. It is estimated that the sink of CO2 into STMW was 0.985 ± 0.018 Pg C (Pg = 1015 g C) between 1988 and 2011 (~70 % of which is due to uptake of Cant). However, the STMW sink of CO2 was strongly coupled to the North Atlantic Oscillation (NAO) with large uptake of CO2 into STMW during the 1990s (NAO positive phase). In contrast, uptake of CO2 into STMW was much reduced in the 2000s during the NAO neutral/negative phase. Thus, NAO induced variability of the STMW CO2 sink is important when evaluating multi-decadal changes in North Atlantic Ocean CO2 sinks.

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Dynamical Response of the Oceanic Eddy Field to the North Atlantic Oscillation: A Model–Data Comparison

Journal of Physical Oceanography ◽

10.1175/jpo2618.1 ◽

2004 ◽

Vol 34 (12) ◽

pp. 2615-2629 ◽

Cited By ~ 45

Author(s):

Thierry Penduff ◽

Bernard Barnier ◽

W. K. Dewar ◽

James J. O'Brien

Keyword(s):

Atlantic Ocean ◽

North Atlantic Oscillation ◽

Time Scales ◽

North Atlantic ◽

Distribution Model ◽

Altimeter Data ◽

Dynamical Response ◽

The North ◽

The North Atlantic ◽

The North Atlantic Oscillation

Abstract Observational studies have shown that in many regions of the World Ocean the eddy kinetic energy (EKE) significantly varies on interannual time scales. Comparing altimeter-derived EKE maps for 1993 and 1996, Stammer and Wunsch have mentioned a significant meridional redistribution of EKE in the North Atlantic Ocean and suggested the possible influence of the North Atlantic Oscillation (NAO) cycle. This hypothesis is examined using 7 yr of Ocean Topography Experiment (TOPEX)/Poseidon altimeter data and three ⅙°-resolution Atlantic Ocean model simulations performed over the period 1979–2000 during the French “CLIPPER” experiment. The subpolar–subtropical meridional contrast of EKE in the real ocean appears to vary on interannual time scales, and the model reproduces it realistically. The NAO cycle forces the meridional contrast of energy input by the wind. The analysis in this paper suggests that after 1993 the large amplitude of the NAO cycle induces changes in the transport of the baroclinically unstable large-scale circulation (Gulf Stream/North Atlantic Current) and, thus, changes in the EKE distribution. Model results suggest that NAO-like fluctuations were not followed by EKE redistributions before 1994, probably because NAO oscillations were weaker. Strong NAO events after 1994 were followed by gyre-scale EKE fluctuations with a 4–12-month lag, suggesting that complex, nonlinear adjustment processes are involved in this oceanic adjustment.

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Tracers, time scales, and the thermohaline circulation: The lower limb in the North Atlantic Ocean

Reviews of Geophysics ◽

10.1029/95rg00492 ◽

1995 ◽

Vol 33 (S2) ◽

pp. 1353-1365 ◽

Cited By ~ 21

Author(s):

Rana A. Fine

Keyword(s):

Atlantic Ocean ◽

Time Scales ◽

North Atlantic ◽

Lower Limb ◽

Thermohaline Circulation ◽

North Atlantic Ocean ◽

The North ◽

The North Atlantic

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Atmospheric response to the North Atlantic Ocean variability on seasonal to decadal time scales

Climate Dynamics ◽

10.1007/s00382-012-1333-0 ◽

2012 ◽

Vol 40 (9-10) ◽

pp. 2311-2330 ◽

Cited By ~ 57

Author(s):

Guillaume Gastineau ◽

Fabio D’Andrea ◽

Claude Frankignoul

Keyword(s):

Atlantic Ocean ◽

Time Scales ◽

North Atlantic ◽

North Atlantic Ocean ◽

Atmospheric Response ◽

Ocean Variability ◽

The North ◽

The North Atlantic

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Recent Decadal Trend in the North Atlantic Wind Energy Resources

Advances in Meteorology ◽

10.1155/2017/7257492 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Chong Wei Zheng ◽

Chong Yin Li ◽

Xin Li

Keyword(s):

Atlantic Ocean ◽

Wind Energy ◽

North Atlantic ◽

North Atlantic Ocean ◽

Climatic Trend ◽

The North ◽

Increasing Trend ◽

The North Atlantic ◽

The North Atlantic Oscillation ◽

June July

This study presents the climatic trend of the North Atlantic wind energy using cross-calibrated, multiplatform (CCMP) wind data for the period 1988–2011. Results show the following. (1) The North Atlantic WPD exhibited a significant increasing trend of 4.45 (W/m2)/yr over the past 24 years. (2) The variation in the North Atlantic Ocean WPD shows a noticeable regional difference. More than half of the North Atlantic Ocean has a significantly increasing trend in WPD. The increasing trend in the mid-high latitudes is stronger than that in the low latitudes, and the trend is stronger in the west than in the east. The area with the strongest increasing trend is located along the southern coast of Greenland of 35 (W/m2)/yr. (3) There is a noticeable seasonal difference in the variation of WPD. The strongest increasing trend occurs in December-January-February (DJF), followed by September-October-November (SON) and March-April-May (MAM), and the weakest occurs in June-July-August (JJA). The increasing trend in different areas is dominated by different seasons. (4) There is no leading or lagging correlation between WPD and the North Atlantic Oscillation (NAO). However, there is a noticeable negative correlation between the Niño3 index and WPD in most of the North Atlantic.

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Are the North Atlantic Oscillation and the Southern Oscillation related in any time-scale?

Annales Geophysicae ◽

10.1007/s005850050027 ◽

2000 ◽

Vol 18 (2) ◽

pp. 0247-0251

Author(s):

R. García ◽

P. Ribera ◽

L. Gimenoo ◽

E. Hernández

Keyword(s):

North Atlantic Oscillation ◽

North Atlantic ◽

Time Scale ◽

Southern Oscillation ◽

The North ◽

The North Atlantic ◽

The North Atlantic Oscillation

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Multidecadal Covariability of North Atlantic Sea Surface Temperature, African Dust, Sahel Rainfall, and Atlantic Hurricanes

Journal of Climate ◽

10.1175/jcli-d-11-00413.1 ◽

2012 ◽

Vol 25 (15) ◽

pp. 5404-5415 ◽

Cited By ~ 100

Author(s):

Chunzai Wang ◽

Shenfu Dong ◽

Amato T. Evan ◽

Gregory R. Foltz ◽

Sang-Ki Lee

Keyword(s):

Atlantic Ocean ◽

Time Scales ◽

North Atlantic ◽

North Atlantic Ocean ◽

African Dust ◽

The North ◽

Tropical North Atlantic ◽

Sahel Rainfall ◽

The North Atlantic ◽

Atlantic Hurricanes

Abstract Most studies of African dust and North Atlantic climate have been limited to the short time period since the satellite era (1980 onward), precluding the examination of their relationship on longer time scales. Here a new dust dataset with the record extending back to the 1950s is used to show a multidecadal covariability of North Atlantic SST and aerosol, Sahel rainfall, and Atlantic hurricanes. When the North Atlantic Ocean was cold from the late 1960s to the early 1990s, the Sahel received less rainfall and the tropical North Atlantic experienced a high concentration of dust. The opposite was true when the North Atlantic Ocean was warm before the late 1960s and after the early 1990s. This suggests a novel mechanism for North Atlantic SST variability—a positive feedback between North Atlantic SST, African dust, and Sahel rainfall on multidecadal time scales. That is, a warm (cold) North Atlantic Ocean produces a wet (dry) condition in the Sahel and thus leads to low (high) concentration of dust in the tropical North Atlantic, which in turn warms (cools) the North Atlantic Ocean. An implication of this study is that coupled climate models need to be able to simulate this aerosol-related feedback in order to correctly simulate climate variability in the North Atlantic. Additionally, it is found that dust in the tropical North Atlantic varies inversely with the number of Atlantic hurricanes on multidecadal time scales because of the multidecadal variability of both direct and indirect influences of dust on vertical wind shear in the hurricane main development region.

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