Ice cores reveal a slow decline in atmospheric oxygen over the last 800,000 years (Science)

By Morgan Kelly, Office of Communications Princeton University researchers have compiled 30 years of data to construct the first ice core-based record of atmospheric oxygen concentrations spanning the past 800,000 years, according to a paper published today in the journal Science. The record shows that atmospheric oxygen has declined 0.7 percent relative to current atmospheric-oxygen … Continue reading Ice cores reveal a slow decline in atmospheric oxygen over the last 800,000 years (Science)

On warmer Earth, most of Arctic may remove, not add, methane (ISME Journal)

By Morgan Kelly, Office of Communications In addition to melting icecaps and imperiled wildlife, a significant concern among scientists is that higher Arctic temperatures brought about by climate change could result in the release of massive amounts of carbon locked in the region's frozen soil in the form of carbon dioxide and methane. Arctic permafrost … Continue reading On warmer Earth, most of Arctic may remove, not add, methane (ISME Journal)

Dirty pool: Soil’s large carbon stores could be freed by increased CO2, plant growth (Nature Climate Change)

By Morgan Kelly, Office of Communications An increase in human-made carbon dioxide in the atmosphere could initiate a chain reaction between plants and microorganisms that would unsettle one of the largest carbon reservoirs on the planet — soil. Researchers based at Princeton University report in the journal Nature Climate Change that the carbon in soil … Continue reading Dirty pool: Soil’s large carbon stores could be freed by increased CO2, plant growth (Nature Climate Change)

Study resolves controversy over nitrogen’s ocean “exit strategies” (Science)

By Catherine Zandonella, Office of the Dean for Research A decades-long debate over how nitrogen is removed from the ocean may now be settled by new findings from researchers at Princeton University and their collaborators at the University of Washington. The debate centers on how nitrogen — one of the most important food sources for … Continue reading Study resolves controversy over nitrogen’s ocean “exit strategies” (Science)

Asian ozone pollution in Hawaii is tied to climate variability (Nature Geoscience)

By Joanne Curcio, Program in Atmospheric and Oceanic Sciences Air pollution from Asia has been rising for several decades but Hawaii had seemed to escape the ozone pollution that drifts east with the springtime winds. Now a team of researchers has found that shifts in atmospheric circulation explain the trends in Hawaiian ozone pollution. The … Continue reading Asian ozone pollution in Hawaii is tied to climate variability (Nature Geoscience)

Migrating animals add new depth to how the ocean “breathes” (Nature Geoscience)

By Morgan Kelly, Office of Communications The oxygen content of the ocean may be subject to frequent ups and downs in a very literal sense — that is, in the form of the numerous sea creatures that dine near the surface at night then submerge into the safety of deeper, darker waters at daybreak. Research … Continue reading Migrating animals add new depth to how the ocean “breathes” (Nature Geoscience)

Pebbles and sand on Mars best evidence that a river ran through it (Science)

By Morgan Kelly, Office of Communications Pebbles and sand scattered near an ancient Martian river network may present the most convincing evidence yet that the frigid deserts of the Red Planet were once a habitable environment traversed by flowing water. Scientists with NASA's Mars Science Laboratory mission reported May 30 in the journal Science the … Continue reading Pebbles and sand on Mars best evidence that a river ran through it (Science)

How the ice ages ended (Nature)

by Catherine Zandonella, Office of the Dean for Research A study of sediment cores collected from the deep ocean supports a new explanation for how glacier melting at the end of the ice ages led to the release of carbon dioxide from the ocean. The study published in Nature suggests that melting glaciers in the … Continue reading How the ice ages ended (Nature)

New approach can rapidly estimate damage from earthquakes (Bulletin of the Seismological Society of America)

A new approach that can rapidly estimate damage to tall buildings following a large earthquake has been developed by researchers. The approach involves creating a database of building responses to typical earthquake-related ground motions. After an earthquake, an analysis of the ground motions can indicate what type of damage is likely to have occurred to … Continue reading New approach can rapidly estimate damage from earthquakes (Bulletin of the Seismological Society of America)

Changes in Greenland ice sheet over space and time (PNAS)

Polar ice sheets are melting and contributing to a global rise in sea-level. This study looked at changes in Greenland's ice sheet from April 2002 to August 2011 and found that active areas of ice loss were concentrated on the southeastern and northwestern coasts, with ice mass in the center of Greenland steadily increasing over … Continue reading Changes in Greenland ice sheet over space and time (PNAS)