[1] The anthropogenic CO2 accumulation rate for the North Atlantic Ocean was estimated on the basis of the decrease in the dC of the dissolved inorganic carbon measured between cruises in 1981 (Transient Tracers in the North Atlantic), 1993 (OACES) and 2003 (Repeat Hydrography). A mean depth-integrated dC change of 15.0 ± 3.8% m yr 1 was estimated by applying a multiple linear regression approa...

One of the most characteristic features in ocean productivity is the North Atlantic spring bloom. Responding to seasonal increases in irradiance and stratification, surface phytopopulations rise significantly, a pattern that visibly tracks poleward into summer. While blooms also occur in the Arctic Ocean, they are constrained by the sea-ice and strong vertical stratification that characterize t...

As a key persistent component of the atmospheric dynamics, the North Atlantic blocking activity has been linked to extreme climatic phenomena in the European sector. It has also been linked to Atlantic multidecadal ocean variability, but its potential links to rapid oceanic changes have not been investigated. Using a global ocean-sea ice model forced with atmospheric reanalysis data, here it is...

A b s t rac t. Interocean exchange of heat and salt around South Africa is thought to be a key link in the maintenance of the global overturning circulation of the ocean. It takes place at the Agulhas Retroflection, largely by the intermittent shedding of enormous rings that penetrate into the South Atlantic Ocean. This makes it extremely hard to estimate the inter ocean fluxes. Estimates of di...

Substantial changes occurred in the North Atlantic during the twentieth century. Here the authors demonstrate, through the analysis of a vast collection of observational data, that multidecadal fluctuations on time scales of 50–80 yr are prevalent in the upper 3000 m of the North Atlantic Ocean. Spatially averaged temperature and salinity from the 0–300and 1000–3000-m layers vary in opposition:...

This chapter discusses the stability of the Atlantic thermohaline circulation with special emphasis on the critical thresholds and state transitions found in model experiments. The thermohaline ocean circulation is a major heat transport mechanism which causes the relatively mild climate in the North Atlantic region (including Europe) in the modern times. The formation of North Atlantic Deep Wa...

The deep-sea environments of the South Atlantic Ocean are less studied in comparison to the North Atlantic and Pacific Oceans. With the aim of identifying the deep-sea bacteria in this less known ocean, 70 strains were isolated from eight sediment samples (depth range between 1905 to 5560 m) collected in the eastern part of the South Atlantic, from the equatorial region to the Cape Abyssal Plai...

The quantitative role of the Atlantic Meridional Overturning Circulation (AMOC) in dissolved organic carbon (DOC) export is evaluated by combining DOC measurements with observed water mass transports. In the eastern subpolar North Atlantic, both upper and lower limbs of the AMOC transport high-DOC waters. Deep water formation that connects the two limbs of the AMOC results in a high downward ex...

A high-resolution, off-line, ocean general circulation model, incorporating a realistic parameterisation of mixed layer convection is used to diagnose pathways and timescales of Southern Hemisphere Intermediate, Mode and thermocline water ventilation. Simulated and observed CFC-11 are in reasonably good agreement, demonstrating the model’s skill in representing realistic ventilation. Regional p...

Although the seasonal cycle of the equatorial Atlantic and Pacific Oceans have many similarities, for example, an annual signal is dominant at the equator even though the sun ‘‘crosses’’ the equator twice a year, different processes determine the seasonal cycles of the two oceans and in the Atlantic different processes are important in the east and west. In the Gulf of Guinea in the eastern equ...