scholarly journals Stochastic forcing of north tropical Atlantic sea surface temperatures by the North Atlantic Oscillation

2014 ◽  
Vol 41 (6) ◽  
pp. 2126-2132 ◽  
Author(s):  
Cécile Penland ◽  
Leslie M. Hartten
Keyword(s):  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Tropical Atlantic ◽  
Stochastic Forcing ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
North Tropical Atlantic

scholarly journals The North Atlantic Oscillation and sea surface temperature affect loggerhead abundance around the Strait of Gibraltar

2011 ◽  
Vol 75 (3) ◽  
pp. 571-575 ◽  
Author(s):  
José C. Báez ◽  
Juan J. Bellido ◽  
Francisco Ferri-Yáñez ◽  
Juan J. Castillo ◽  
Juan J. Martín ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Sea Surface ◽  
Strait Of Gibraltar ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

scholarly journals Stochastic Forcing of Ocean Variability by the North Atlantic Oscillation

2009 ◽  
Vol 39 (1) ◽  
pp. 162-184 ◽  
Author(s):  
Kettyah C. Chhak ◽  
Andrew M. Moore ◽  
Ralph F. Milliff
Keyword(s):  
North Atlantic Oscillation ◽  
Ocean Circulation ◽  
Rossby Wave ◽  
North Atlantic ◽  
Large Scale ◽  
Western Boundary ◽  
Stochastic Forcing ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

Abstract At middle and high latitudes, the magnitude of stochastic wind stress forcing of the ocean by atmospheric variability on synoptic time scales (i.e., “weather” related variability) is comparable to that of the seasonal cycle. Stochastic forcing may therefore have a significant influence on the ocean circulation, climate, and ocean predictability. Here, the influence of stochastic forcing associated with the North Atlantic Oscillation on the subtropical gyre circulation of the North Atlantic is explored in an eddy-permitting quasigeostrophic framework. For the North Atlantic winds used in this study, the root-mean-square of the annual average Ekman pumping velocity of the seasonal cycle between 35° and 52°N is 1.3 × 10−7 m s−1, while the wintertime standard deviation of the stochastic component of the North Atlantic Oscillation over the same latitude band is 2.2 × 10−7 m s−1. Significant stochastically induced variability in the ocean circulation occurs near the western boundary region and along the western margins of the abyssal plains associated with vortex stretching, energy release from the mean flow, and the generation of topographic Rossby waves. Variability arises from a combination of two effects, depending on the measure of variance used: growth of unstable modes of the underlying circulation and modal interference resulting from their nonnormal nature, which dominates during the first 10 days or so of perturbation growth. Near the surface, most of the variability is associated with large-scale changes in the barotropic circulation, although more than 20% of the energy and enstrophy variability is associated with small-scale baroclinic waves. In the deep ocean, much of the stochastically induced variability is apparently due to topographic Rossby wave activity along the continental rise and ocean ridges. Previous studies have demonstrated that rectification of topographic Rossby wave–induced circulations in the western North Atlantic may contribute to the western boundary current recirculation zones. The authors suggest that a source of topographic Rossby wave energy, significant enough to rectify the mean ocean circulation, may arise from stochastic forcing by large-scale atmospheric forcing, such as the North Atlantic Oscillation and other atmospheric teleconnection patterns.

The influence of the North Atlantic Oscillation on the sea-level around the northern European coasts reconsidered: the thermosteric effects

2006 ◽  
Vol 364 (1841) ◽  
pp. 845-856 ◽  
Author(s):  
M.N Tsimplis ◽  
A.G.P Shaw ◽  
R.A Flather ◽  
D.K Woolf
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic Oscillation ◽  
Sea Level ◽  
North Atlantic ◽  
Sea Surface ◽  
Sea Level Changes ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

The thermosteric contribution of the North Atlantic Oscillation (NAO) to the North Sea sea-level for the winter period is investigated. Satellite sea surface temperature as well as in situ measurements are used to define the sensitivity of winter water temperature to the NAO as well as to determine the trends in temperature. The sea surface temperature sensitivity to the NAO is about 0.85 °C per unit NAO, which results in thermosteric sea-level changes of about 1–2 cm per unit NAO. The sensitivity of sea surface temperatures to the NAO is strongly time-dependent. Model data from a two-dimensional hydrodynamic tide+surge model are used in combination with the estimated thermosteric anomalies to explain the observed sea-level changes and, in particular, the sensitivity of the datasets to the NAO variability. The agreement between the model and the observed data is improved by the inclusion of the thermosteric effect.

scholarly journals Mid to late-Holocene sea-surface temperature variability off north-eastern Newfoundland and its linkage to the North Atlantic Oscillation

The Holocene ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Lisa C Orme ◽  
Arto Miettinen ◽  
Marit-Solveig Seidenkrantz ◽  
Kirsi Tuominen ◽  
Christof Pearce ◽  
...  
Keyword(s):  
Surface Temperature ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Late Holocene ◽  
Sea Surface ◽  
Labrador Sea ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

In recent decades the surface water temperature and salinity in the Labrador Sea have been influenced by atmospheric circulation patterns, such as the North Atlantic Oscillation (NAO), as well as a trend to increasingly warm atmospheric temperatures in recent years. These changes are concerning, given the important role that temperature and salinity have on deep convection in the Labrador Sea. Yet, due to the shortness of available records, the long-term patterns of climate variability in the region are not clear. Here, a diatom-based reconstruction of summer sea-surface temperature (SST) developed from Trinity Bay, Newfoundland, provides insight into variations of SST since 7.2 cal ka BP in the southwestern Labrador Sea. The results show that the Holocene Thermal Maximum (HTM) lasted until c. 5.2 cal ka BP, which was followed by a gradual cooling trend overprinted by centennial temperature fluctuations of 1–2°C. Long-term cooling was likely the result of declining Northern Hemisphere orbital summer insolation, potentially amplified by long-term changes in surface and bottom water salinity, which led to a gradual reduction in the stratification of the water column. Centennial fluctuations in temperature vary in-phase with reconstructed variations in the NAO, supporting a consistent relationship between atmospheric circulation and SST over centennial-millennial timescales. Other factors influencing the SST variability may have been solar forcing during the mid-Holocene and variations in the strength of the subpolar gyre during the late-Holocene. The most prolonged cool period at 5.2–4.1 cal ka BP coincides with sharply reduced salinity in the Labrador Sea and a weakening of deep ventilation in the northeast Atlantic, highlighting a period with altered ocean surface conditions and circulation across the northern North Atlantic.

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