Archaeological excavations of historical fishing sites across the North Atlantic have recovered high quantities of Atlantic cod (Gadus morhua) bones. In the current study we use Atlantic cod otoliths from archaeological excavations of a historical fishing sites in north-west Iceland, dated to AD 970 -AD 1910 to examine historical growth trajectories of cod. No large scale growth variations or s...

Analysis of sea surface temperature (SST) observations suggests a pan-oceanic interaction between the tropical Pacific and the Atlantic Ocean at multi-decadal time scales, such that periods of anomalously high SSTs in the eastern tropical Pacific are followed by a basinwide SST dipole in the Atlantic Ocean with a time delay of a few decades. The SST anomaly structure in the Atlantic Ocean is re...

North Atlantic sea ice anomalies are thought to play an important role in the abrupt Dansgaard–Oeschger (D–O) cycles of the last glacial period. This model study investigates the impacts of changes in North Atlantic sea ice extent in glacial climates to help provide geographical constraints on their involvement in D–O cycles. Based on a coupled climate model simulation of the Last Glacial Maxim...

Approximately synchronous with the onset of Heinrich Stadial 1 (HS1), δC decreased throughout most of the upper (~1000–2500m) Atlantic, and at some deeper North Atlantic sites. This early deglacial δC decrease has been alternatively attributed to a reduced fraction of high-δC North Atlantic Deep Water (NADW) or to a decrease in the NADW δC source value. Here we present new benthic δO and δC rec...

[1] Oxygen isotopic records of meltwater outflow and records of sea level change do not support the idea that fresh waters derived solely from the melting of Northern Hemisphere ice sheets was likely to have stabilized the upper layers of the North Atlantic Ocean and prevented deep convection during the Younger Dryas. Yet there are paleoceanographic indicators that point to a pause in the forma...

Numerical simulations of the Atlantic Ocean during the period 1950 to 1989, using a sigma coordinate, free surface numerical model, show long-term variabilities in the upper ocean subtropical gyre similar to those obtained from observations. The simulations show how westward propagating planetary waves, originated in the eastern North Atlantic, affect interdecadal variabilities of ocean propert...

The North Atlantic is one of the few places on the globe where the atmosphere is linked to the deep ocean through air—sea interaction. While the internal variability of the atmosphere by itself is only predictable over a period of one to two weeks, climate variations are potentially predictable for much longer periods of months or even years because of coupling with the ocean. This work present...

[1] Observational analyses suggest that the northern North Atlantic is fresher in the late 20th century in comparison to the 1950–60s. Here we examine possible contributors to these observed changes by analyzing a four-member ensemble of 20th century simulations from a coupled climate model. Results show that a weaker meridional freshwater divergence related to a weaker thermohaline circulation...

Most projections of greenhouse gas–induced climate change indicate a weakening of the thermohaline circulation (THC) in the North Atlantic in response to increased freshening and warming in the subpolar region. These changes reduce high-latitude upper-ocean density and therefore weaken the THC. Using ensembles of numerical experiments with a coupled ocean–atmosphere model, it is found that this...

Most projections of greenhouse gas-induced climate change indicate a weakening of the thermohaline circulation (THC) in the North Atlantic in response to increased freshening and warming in the subpolar region. These changes reduce high latitude upper ocean density, and therefore weaken the THC. Using ensembles of numerical experiments with a coupled ocean-atmosphere model, it is found that thi...