scholarly journals The Freshwater Balance Over the North Atlantic SPURS Domain from Aquarius Satellite Salinity, OSCAR Satellite Surface Currents, and Some Simplified Approaches

Oceanography ◽  
2015 ◽  
Vol 28 (1) ◽  
pp. 86-95 ◽  
Author(s):  
Kathleen Dohan ◽  
◽  
Hsun-Ying Kao ◽  
Gary Lagerloef
Keyword(s):  
North Atlantic ◽  
Surface Currents ◽  
The North ◽  
The North Atlantic ◽  
Freshwater Balance

scholarly journals Impacts of Changed Ice-Ocean Stress on the North Atlantic Ocean: Role of Ocean Surface Currents

2021 ◽  
Vol 8 ◽  
Author(s):  
Yang Wu ◽  
Zhaomin Wang ◽  
Chengyan Liu
Keyword(s):  
Atlantic Ocean ◽  
Sea Ice ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Ocean Surface ◽  
Surface Currents ◽  
Stress Calculation ◽  
The North ◽  
Ocean Surface Currents ◽  
The North Atlantic

The importance of considering ocean surface currents in ice-ocean stress calculation in the North Atlantic Ocean and Arctic sea ice is investigated for the first time using a global coupled ocean-sea ice model. Considering ocean surface currents in ice-ocean stress calculation weakens the ocean surface stress and Ekman pumping by about 7.7 and 15% over the North Atlantic Ocean, respectively. It also significantly reduces the mechanical energy input to ageostrophic and geostrophic currents, and weakens the mean and eddy kinetic energy by reducing the energy conversion rates of baroclinic and barotropic pathways. Furthermore, the strength of the Atlantic Meridional Overturning Circulation (AMOC), the Nordic Seas MOC, and the North Atlantic subpolar gyre are found to be reduced considerably (by 14.3, 31.0, and 18.1%, respectively). The weakened AMOC leads to a 0.12 PW reduction in maximum northward ocean heat transport, resulting in a reduced surface heat loss and lower sea surface temperature over the North Atlantic Ocean. This reduction also leads to a shrink in sea ice extent and an attenuation of sea ice thickness. These findings highlight the importance of properly considering both the geostrophic and ageostrophic components of ocean surface currents in ice-ocean stress calculation on ocean circulation and climate studies.

The Impact of Tropical Atlantic Freshwater Fluxes on the North Atlantic Meridional Overturning Circulation

2006 ◽  
Vol 19 (18) ◽  
pp. 4592-4604 ◽  
Author(s):  
J. Paul Spence ◽  
Andrew J. Weaver
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Tropical Atlantic ◽  
Deep Water Formation ◽  
The North ◽  
Freshwater Fluxes ◽  
Water Formation ◽  
Meridional Overturning ◽  
The North Atlantic ◽  
Freshwater Balance

Abstract The influence of ENSO-related changes in the Atlantic-to-Pacific freshwater budget on the North Atlantic meridional overturning is examined using the University of Victoria (UVic) Earth System Climate Model. The initial analysis of freshwater fluxes in the 50-yr NCEP–NCAR (NCEP50) reanalysis product and Global Precipitation Climatology Project (GPCP) dataset reveals that the transport of water vapor out of the tropical Atlantic drainage basin is enhanced during El Niño phases and reduced during La Niña phases; a one standard deviation in the Southern Oscillation index alters the tropical Atlantic freshwater balance by about 0.09 Sv (Sv ≡ 106 m3 s−1). A weaker link with ENSO is found in the 40-yr ECMWF Re-Analysis (ERA-40), although its usefulness is severely limited by a strong and spurious trend in tropical precipitation. Model results suggest that tropical Atlantic salinity anomalies generated with the frequency and amplitude of ENSO tend not to impact deep-water formation as they are diluted en route to the North Atlantic. Lower frequency, decadal time-scale anomalies, however, do have an impact, albeit weak, on the rate of North Atlantic Deep Water formation. In addition, and contrary to earlier results, it is found that even a shift of the tropical Atlantic freshwater balance toward permanent El Niño conditions only slightly mitigates the transient reduction of North Atlantic Deep Water formation associated with the increase of anthropogenic greenhouse gases. Taken together, the results suggest that the poleward propagation of salinity anomalies from the tropical Atlantic, associated with changes in ENSO, should not be considered a significant mechanism for the variability of the North Atlantic meridional overturning in the present and foreseeable future climate.

The Currents of the North Atlantic

1892 ◽  
Vol 34 (872supp) ◽  
pp. 13940-13941
Author(s):  
Richard Beynon
Keyword(s):  
North Atlantic ◽  
The North ◽  
The North Atlantic

NATO adaptation to current challenges and mechanisms of Ukraine’s cooperation with the North Atlantic Treaty Organization

2019 ◽  
pp. 73-81
Author(s):  
Oleh Poshedin
Keyword(s):  
North Atlantic ◽  
Task Force ◽  
Response Force ◽  
Cyber Attack ◽  
Adaptation Measures ◽  
Joint Force ◽  
Security Environment ◽  
The North ◽  
The North Atlantic ◽  
Area Of Influence

The purpose of the article is to describe the changes NATO undergoing in response to the challenges of our time. Today NATO, as a key element of European and Euro-Atlantic security, is adapting to changes in the modern security environment by increasing its readiness and ability to respond to any threat. Adaptation measures include the components required to ensure that the Alliance can fully address the security challenges it might face. Responsiveness NATO Response Force enhanced by developing force packages that are able to move rapidly and respond to potential challenges and threats. As part of it, was established a Very High Readiness Joint Task Force, a new Allied joint force that deploy within a few days to respond to challenges that arise, particularly at the periphery of NATO’s territory. NATO emphasizes, that cyber defence is part of NATO’s core task of collective defence. A decision as to when a cyber attack would lead to the invocation of Article 5 would be taken by the North Atlantic Council on a case-by-case basis. Cooperation with NATO already contributes to the implementation of national security and defense in state policy. At the same time, taking into account that all decision-making in NATO based on consensus, Ukraine’s membership in the Alliance quite vague perspective. In such circumstances, in Ukraine you often can hear the idea of announcement of a neutral status. It is worth reminding that non-aligned status did not save Ukraine from Russian aggression. Neutral status will not accomplish it either. All talks about neutrality and the impossibility of Ukraine joining NATO are nothing but manipulations, as well as recognition of the Ukrainian territory as Russian Federation area of influence (this country seeks to sabotage the Euro-Atlantic movement of Ukraine). Think about it, Moldova’s Neutrality is enshrined in the country’s Constitution since 1994. However, this did not help Moldova to restore its territorial integrity and to force Russia to withdraw its troops and armaments from Transnistria.

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