Particles from the upper atmosphere trapped in a deep pile of Antarctic snow hold clear chemical traces of global meteorological events, a team from the University of California, San Diego and a colleague from France have found.
Earth
The world has suffered from severe regional weather extremes in recent years, such as the heat wave in the United States in 2011 or the one in Russia 2010 coinciding with the unprecedented Pakistan flood. Behind these devastating individual events there is a common physical cause, propose scientists of the Potsdam Institute for Climate Impact Research (PIK).
While short-term weather is notoriously volatile, climate is thought to represent a kind of average weather pattern over a long period of time. This dichotomy provides the analytical framework for scientific thinking about atmospheric variability, including climate change.
MIAMI – February 25, 2013 -- In a study published today in Nature Climate Change researchers used the latest emissions scenarios and climate models to show how varying levels of carbon emissions are likely to result in more frequent and severe coral bleaching events.
Cambridge, Mass. – February 25, 2013 – "People have often thought there's no upper bound for wind power—that it's one of the most scalable power sources," says Harvard applied physicist David Keith. After all, gusts and breezes don't seem likely to "run out" on a global scale in the way oil wells might run dry.
Yet the latest research in mesoscale atmospheric modeling, published today in the journal Environmental Research Letters, suggests that the generating capacity of large-scale wind farms has been overestimated.
University of Alberta researchers have found a way to replace artificial preservatives in bread, making it tastier.
CAMBRIDGE, MA -- While the phenomenon of superconductivity — in which some materials lose all resistance to electric currents at extremely low temperatures — has been known for more than a century, the temperature at which it occurs has remained too low for any practical applications. The discovery of "high-temperature" superconductors in the 1980s — materials that could lose resistance at temperatures of up to negative 140 degrees Celsius — led to speculation that a surge of new discoveries might quickly lead to room-temperature superconductors.
Engineers and scientists from the University of Sheffield have pioneered a new technique to analyse PCBM, a material used in polymer photovoltaic cells, obtaining details of the structure of the material which will be vital to improving the cell's efficiency. The findings are published in Applied Physics Letters.
The new study in Nature Climate Change shows that reaching the 3 energy-related objectives proposed by the United Nations in their Sustainable Energy for All (SE4All) initiative, launched in 2011, would reduce emissions of greenhouse gases that contribute to climate change and, in combination with other measures, could help keep global temperature rise from exceeding the internationally agreed target level of 2°C.
The islands Reunion and Mauritius, both well-known tourist destinations, are hiding a micro-continent, which has now been discovered. The continent fragment known as Mauritia detached about 60 million years ago while Madagascar and India drifted apart, and had been hidden under huge masses of lava. Such micro-continents in the oceans seem to occur more frequently than previously thought, says a study in the latest issue of Nature Geoscience ("A Precambrian microcontinent in the Indian Ocean," Nature Geoscience, Vol 6, doi: 10.1038/NGEO1736).
One recurrently forecast effect of global climate change is that in general, precipitation patterns will become more extreme, with fewer, larger storms and longer dry spells in between. The aftermath of this shift, borne out by the effect the changing water availability will have on vegetative productivity, however, is less well known. Previous research showed that productivity changes with the total annual precipitation, but the measured effect of a shift to a more extreme distribution is less consistent.
On August 31st, 2012, a magnitude 7.6 earthquake ruptured deep beneath the sea floor of the Philippine Trench, a powerful intraplate earthquake centered seaward of the plate boundary. In the wake of the main shock, sensors detected a flurry of aftershocks, counting 110 in total.
Drawing on seismic wave observations and rupture mechanisms calculated for the aftershocks, Ye et al. find that many were located near the epicenter of the main intraplate quake, but at shallower depth and all involving normal faulting.
In the North American Arctic the Mackenzie River courses into the Beaufort Sea, the outlet of a watershed that drains a vast swath of the western Canadian landscape. At the river's mouth, the Mackenzie Delta is a broad floodplain peppered with roughly 45,000 lakes carved into the permafrost.
Depending on their connectivity to the river, these floodplain lakes have different mixtures of organic compounds, and such differences affect carbon cycling and sediment processes in the lakes.
As ocean waves pass from deeper water into the shallow coastal regions, they begin to break, churning up the surf zone waters. At the edges of the crests of the breaking waves, horizontally-rotating eddies (vertical vortices) are generated, converting some of the waves' kinetic energy into turbulence.
These horizontally-rotating eddies are an important mechanism for dispersing nutrients, larvae, bacteria, sediments, and other suspended objects along the coastline.
The past few years have seen powerful droughts across the U.S., with water shortages threatening crop production, shipping traffic, energy production, and groundwater stores.
Water scarcity issues are particularly relevant for those living in cities, a demographic which now includes roughly 4 out of every 5 Americans. Previous research has tallied average daily water needs, estimated at 600 liters (about 160 gallons) per person per day, and the availability of natural renewable water resources.