Browse Highlights

Highlights are short summaries of notable articles.

Ancient corals off the coast of New England, collected a kilometer or two underwater, reveal that rapid shifts in ocean circulation occurred as glaciers receded and the planet moved out of the last ice age. Wilson et al. determined this information using neodymium (Nd) isotopes measured in samples of.... more

During the latter half of the Cenozoic, starting during the Pliocene, the eastern equatorial Pacific (EEP) underwent a change from warm, wet climate conditions—which scientists refer to as “permanent El Niño”—to more moderate conditions like those observed today. Although scientists can track this change.... more

After the fairly warm Miocene climate optimum about 17–15 million years ago, Earth’s climate began to cool. Holbourn et al. present a new high-resolution record of climate evolution over the middle to late Miocene from 12.9 to 8.4 million years ago based on stable isotopes in sedimentary benthic foraminifera.... more

A sudden surge in the concentration of carbon dioxide in the air and the ocean 56 million years ago may have triggered the Paleocene-Eocene thermal maximum (PETM), a period of rapid and dramatic warming. In conjunction with the rising atmospheric temperature, ocean acidification significantly increased.... more

Multiple times in the Earth's past, the air over Greenland has warmed by 10°C or more in just a few decades before slowly resetting over centuries. First discovered in the 1990s, these so-called Dansgaard-Oeschger (D-O) events are spurred by an unknown cause. Dokken et al. propose that D-O events are.... more

In the western South Atlantic, off the coast of South America, a band of cold, fresh, nutrient-rich Sub-Antarctic Shelf Water (SASW) meets warm, salty, nutrient-poor Subtropical Shelf Water (STSW) to form the Subtropical Shelf Front (STSF). This front is the shallow-water expression of the major Brazil-Malvinas.... more

Measuring isotopes preserved in the shells of ancient single-celled foraminifera, tracking two sets of isotope ratios—carbon-13 to carbon-12, and oxygen-18 to oxygen-16—is one of the main tools used by paleoceanographers to reconstruct the temperature of the ancient ocean and global carbon cycling..... more

Silicon is an essential nutrient for the growth of siliceous phytoplankton, which accounts for a significant amount of marine primary production. Constraints on silicic acid limit primary production and carbon export, so biogeochemical silicon cycling influences the carbon cycle and climate. Silicon.... more

When planktonic foraminifera calcify, the magnesium to calcium (Mg/Ca) ratios in their shells are sensitive to water temperature. This has enabled paleoceanographers to use Mg/Ca ratios measured from multiple fossil foraminifera shells in sediments as a proxy for average water temperatures in the past..... more

Over the tropical Pacific Ocean the Walker circulation is an atmospheric flow pattern that runs parallel to the equator, with ascending motion over the western Pacific and a horizontal tropospheric return flow that carries air back to the east. Scientists predict the Walker circulation will weaken with.... more