Volume 6 Issue 3, March 2013

Over the past fifty years, NASA has pushed the frontiers of science and exploration to the edges of our Solar System. Declining funding for research and robotic missions may leave planetary exploration unfinished and young scientists stranded.

The presence of water in lunar volcanic rocks has been attributed to delivery after the Moon formed. Water detected in rocks from the ancient lunar highlands suggests that the Moon already contained water early in its history, and poses more challenges for the giant impact theory of Moon formation.

Oxygen minimum zones crop up along the eastern boundaries of ocean basins in the low latitudes. A survey of the oxygen minimum zone in the eastern South Pacific points to the coastal zone as a hotspot for anammox-driven marine nitrogen loss.

The evolution of Earth's largest hidden landscape beneath the East Antarctic Ice Sheet is poorly understood. Analyses of offshore sediments confirm that the ice incised deep troughs that host fast-flowing ice streams today, while older landscape features have been preserved.

The Palaeocene–Eocene Thermal Maximum was marked by global warming and ocean acidification. Fossil and experimental analyses show that different species of marine calcifying algae responded very differently to the environmental upheavals.

Where continents break apart, new ocean basins are formed. The discovery of ancient continental minerals on a young, volcanic island suggests that parts of the Indian Ocean floor may be underlain by fragments of a long-lost continent.

Antarctic Bottom Water is formed along the fringes of Antarctica and fills much of the abyssal oceans. Data from moored instruments and tagged marine mammals confirm an unexpected site of bottom water formation at Cape Darnley, west of the Amery Ice Shelf.

Tropical climate and the composition of the global upper atmosphere are affected by the tropical tropopause layer. A synthesis report concludes that transport and mixing in the tropopause region are closely linked with the Asian monsoon and other tropical circulation systems, with possible implications for the impacts of climate change on this important layer.

Water has been detected on the lunar surface and attributed to delivery by impacts and the solar wind to a dry early Moon. Spectroscopic detections of water in lunar anorthosites from the Apollo collection suggest that a significant amount of water is indigenous to the Moon.

The intensity of extreme precipitation rises faster than the rate of increase in the atmosphere’s water-holding capacity. A combination of radar and rain gauge measurements over Germany with synoptic observations and temperature records reveals that convective precipitation, for example from thunderstorms, dominates events of extreme precipitation.

Carbonyl sulphide is taken up by plants, and could potentially serve as a powerful proxy for photosynthetic carbon dioxide uptake. Field measurements in Israel suggest that carbonyl sulphide fluxes provide an independent constraint on indirect estimates of ecosystem photosynthesis.

Predators can potentially influence the exchange of carbon dioxide between ecosystems and the atmosphere. Predator manipulation experiments with fish and invertebrates in a range of freshwater systems suggest that freshwater carbon dioxide emissions are reduced in the presence of predators.

The fast flow of glaciers in Greenland during the summer season has been attributed to seasonal increases in subglacial melt water. Tracking the flow of subglacial water using geochemical tracers reveals the establishment of an increasingly efficient drainage network as the melt season progresses.

The causes for rising temperatures along the Antarctic Peninsula over the past few thousand years have been debated. Analyses of diatom geochemistry and assemblage ecology from Palmer Deep off the western margin of the Antarctic Peninsula reveal that atmospheric processes have dominated glacial ice discharge during the late Holocene.

The topography hidden beneath the East Antarctic ice sheet has been unveiled by airborne surveys. Dating of detrital mineral grains reveals that, in contrast to low pre-glacial erosion rates, strong localized erosion has occurred since the expansion of the ice sheet, suggesting a dynamic early ice sheet.

The Atlantic meridional overturning circulation is a key component of the climate system. Data and climate model reconstructions reveal a decline in the strength of the overturning circulation during the Heinrich1 and Younger Dryas cold events of the last glacial period.

The last glacial period was marked by dramatic climate fluctuations. Sediment records from the Cariaco Basin and the Arabian Sea suggest that cooling in the North Atlantic region was tightly coupled with a southward displacement of the intertropical convergence zone and a weakening of the Indian summer monsoon.

Coccolithophores are a key component of the oceanic food web, and may be sensitive to environmental changes. Modern experiments and an assessment of the fossil record suggest that the response of individual species to a period of ocean acidification in the past may have affected the evolutionary success of these species’ lineages.

Ridges of thick, raised crust on the Indian Ocean floor were thought to be mostly volcanic seamounts formed above the Réunion mantle plume. Dating of zircon minerals in Mauritian lavas, however, indicates that fragments of an ancient microcontinent may be preserved beneath the seamounts, contributing to the thickened crust.

Oxygen minimum zones account for a significant fraction of oceanic nitrogen loss. Observational and experimental data suggest that marine nitrogen loss is strongly tied to organic matter export in the South Pacific oxygen minimum zone.

Antarctic Bottom Water fills much of the global abyssal ocean, and is known to form in three main sites in the Southern Ocean. Data from instrumented elephant seals and moorings suggest an additional source of bottom-water formation in the Cape Darnley polynya that is driven by sea-ice production.