The responses of North Pacific intermediate and deep water ventilation and ocean biogeochemical properties to northern North Atlantic glacial freshwater perturbations are evaluated with a coupled atmosphere–ocean general circulation model MIROC and an earth system model of intermediate complexity LOVECLIM. When the Atlantic meridional overturning circulation (AMOC) is weakened as a result of th...

The role of a Southern Ocean gateway in permitting multiple equilibria of the global ocean thermohaline circulation is examined. In particular, necessary conditions for the existence of multiple equilibria are studied with a coupled climate model, wherein stable solutions are obtained for a range of bathymetries with varying Drake Passage (DP) depths. No transitions to a Northern Hemisphere (NH...

[1] Pathways of subtropical cells (STCs) and the basin-wide meridional overturning circulation (MOC) are studied in the tropical Atlantic using a particle tracking algorithm and transports from a high-resolution ocean model. Here 16 Sv (=10 m s ) of MOC water flows to the equator from the south, primarily in the North Brazil Current. The MOC water recirculates in the tropics and, after crossing...

Atlantic-Mediterranean anchovies were genetically characterized at two polymorphic nuclear loci (intron 6 of two creatine-kinase genes) and compared to reference Engraulis albidus and E. encrasicolus samples from the northern Western Mediterranean to provide new insights into their geographic structure. Northeastern Atlantic anchovy, represented by one sample from the Canary archipelago and one...

Earth’s climate exhibits internal modes of variability on various timescales. Here we investigate multi-decadal variability of the Atlantic meridional overturning circulation (AMOC), Northern Hemisphere sea-ice extent and global mean temperature (GMT) in an ensemble of CMIP5 models under control conditions. We report an inter-annual GMT variability of about ±0.1 C originating solely from natura...

Isotope, aerosol, and methane records document an abrupt cooling event across the Northern Hemisphere at 8.2 kiloyears before present (kyr), while separate geologic lines of evidence document the catastrophic drainage of the glacial Lakes Agassiz and Ojibway into the Hudson Bay at approximately the same time. This melt water pulse may have been the catalyst for a decrease in North Atlantic Deep...

We examined 733 individuals of Fucusspiralis from 21 locations and 1093 Fucusvesiculosus individuals from 37 locations throughout their northern hemisphere ranges using nuclear and mitochondrial markers. Three genetic entities of F. spiralis were recovered. In northern and sympatric populations, the presence of "F. spiralis Low" in the mid-intertidal and "F. spiralis High" in the high-intertida...

STOCK DEFINITION AND GEOGRAPHIC RANGE The northern Gulf of Mexico (i.e., U.S. Gulf of Mexico) continental shelf bottlenose dolphin stock inhabits waters from 20 to 200 m deep in the northern Gulf from the U.S.-Mexican border to the Florida Keys (Figure 1). Both “coastal” and “offshore” ecotypes of bottlenose dolphins occur in the Gulf of Mexico (Hersh and Duffield 1990; LeDuc and Curry 1998). T...