Sprites are an optical phenomenon that occur above thunderstorms, about 37 to 56 miles above the Earth. Atmospheric sprites have been known for nearly a century, but their origins were a mystery. Now, a team of researchers has evidence that sprites form at plasma irregularities and may be useful in remote sensing of the lower ionosphere.
A Northwestern Univ. study by an economist and a chemist reports that when fuel prices drove residents of São Paulo, Brazil, to mostly switch from ethanol to gasoline in their flexible-fuel vehicles, local ozone levels dropped 20%. At the same time, nitric oxide and carbon monoxide concentrations tended to go up.
In formulating policies to address greenhouse gas emissions, or evaluating the potential impact of different energy technologies on global climate change, one of the thorniest issues is how to account for the very distinctive characteristics of various different gases. Methane is a potent greenhouse gas, as well as a significant byproduct of using natural gas. But a direct comparison between methane and carbon dioxide is complicated.
A fluctuating tilt in a planet’s orbit does not preclude the possibility of life, according to new research by a team of astronomers. In fact, sometimes it helps because such “tilt-a-worlds,” as astronomers sometimes call them, are less likely than fixed-spin planets to freeze over, as heat from their host star is more evenly distributed.
Since the discovery of the Antarctic ozone hole, scientists, policymakers and the public have wondered whether we might someday see a similarly extreme depletion of ozone over the Arctic. But a new Massachusetts Institute of Technology study finds some cause for optimism: Ozone levels in the Arctic haven’t yet sunk to the extreme lows seen in Antarctica, because international efforts to limit ozone-depleting chemicals have been successful.
High levels of the greenhouse gas methane were found above shale gas wells at a production point not thought to be an important emissions source, according to a study jointly led by Purdue and Cornell universities. The findings could have implications for the evaluation of the environmental impacts from natural gas production.
The rise and fall of acid rain is a global experiment whose results are preserved in the geologic record. By analyzing samples from the Greenland ice sheet, Univ. of Washington atmospheric scientists found clear evidence of the U.S. Clean Air Act. They also discovered a link between air acidity and how nitrogen is preserved in layers of snow.
The U.N.'s expert panel on climate change is under pressure this week as it considers whether geoengineering should be part of the tool-kit that governments use to keep global warming in check. Drafts leaked before the conference only mentioned one of the proposed options, removing carbon dioxide from the air and storing it underground. But some countries support solar radiation management as well.
An examination of more than 60 years of Indiana tornado climatology data from the National Weather Service's Storm Prediction Center has shown that a majority of tornado touchdowns occurred near areas where dramatically different landscapes meet, such as where a city fades into farmland or a forest meets a plain. According to researchers, forecasters may need to pay closer attention to these "transition zones" to understand tornado risks.
National efforts in the last decade to clear the air of dangerous particulate matter have been so successful that most urban areas have already attained the next benchmark, according to new research by Rice Univ. Atmospheric researchers at Rice studied the state implementation plans from 23 regions mandated by the EPA to reduce particulate matter (PM) smaller than 2.5 um (PM 2.5) to less than 15 micrograms per cubic meter by 2009.
Although markets for trading carbon emission credits to reduce greenhouse gas emissions have stalled in U.S. federal policy-making, carbon markets are emerging at the state level within the U.S. and around the world, teaching us more about what does and doesn't work.
An international research team has documented evidence suggesting that part of the reason that the Earth has become neither sweltering like Venus nor frigid like Mars lies with a built-in atmospheric carbon dioxide regulator. Basically, ”fresh” rock exposed by uplift also emits carbon through a chemical weathering process, which replenishes the atmospheric carbon dioxide.
In 2010, researchers demonstrated for the first time that atmospheric information could be captured by an airborne GPS device. Now, a new technique led by a researcher at Scripps Institution of Oceanography stands to improve weather models and hurricane forecasting by detecting precise conditions in the atmosphere through a new GPS system. A first-time demonstration using this system has captured key meteorological data from aircraft.
According to new research, the ice-free season across the Arctic is getting longer by five days per decade. New analysis of satellite data shows the Arctic Ocean absorbing ever more of the sun’s energy in summer, leading to an ever later appearance of sea ice in the autumn. In some regions, autumn freeze-up is occurring up to 11 days per decade later than it used to.
Astronomers at the Univ. of Washington have developed a new method of gauging the atmospheric pressure of exoplanets, or worlds beyond the solar system, by looking for a certain type of molecule. And if there is life out in space, scientists may one day use this same technique to detect its biosignature, the telltale chemical signs of its presence, in the atmosphere of an alien world.
In recent years, palm oil production has come under fire from environmentalists concerned about the deforestation of land in the tropics to make way for new palm plantations. Now there is a new reason to be concerned about palm oil’s environmental impact, according to researchers at the Univ. of Colorado Boulder.
So-called extremely low-volatility organic compounds, which are produced by plants, have been detected for the first time during field and laboratory experiments in Finland and Germany. The results may help to explain discrepancies between observations and theories about how volatile organic compounds produced by vegetation are converted into atmospheric aerosol. This in turn should improve existing climate models.
Univ. of Georgia (UGA) marine scientists are uncovering the mechanisms that regulate the natural production of an anti-greenhouse gas. A new $2 million National Science Foundation grant will allow the UGA-led research group to further document how genes in ocean microbes transform sulfur into clouds in the Earth's atmosphere.
A new study led by the Joint Institute for Strategic Energy Analysis says that the total impact of switching to natural gas depends heavily on leakage of methane during the natural gas life cycle, and suggests that more can be done to reduce methane emissions and to improve measurement tools which help inform policy choices.
As a range of climate change mitigation scenarios are discussed, Univ. of Washington researchers have found that the injection of sulfate particles into the atmosphere to reflect sunlight and curb the effects of global warming could pose a severe threat if not maintained indefinitely and supported by strict reductions in greenhouse gas emissions.
A new NASA video shows three days of movement, beginning Feb. 10, of a massive winter storm that stretches from the southern U.S. to the northeast. Compiled using NOAA's GOES satellite imagery, the sequence shows snow cover and cloud movements over a true-color image of land and ocean created by data from the Moderate Resolution Imaging Spectroradiometer aboard NASA’s Aqua and Terra satellites.
Methane, a key greenhouse gas, has more than doubled in volume in Earth's atmosphere since 1750. Its increase is believed to be a leading contributor to climate change. But where is the methane coming from? Research by a California Institute of Technology atmospheric chemist suggests that losses of natural gas—our "cleanest" fossil fuel—into the atmosphere may be a larger source than previously recognized.
A team of researchers led by Virginia Tech and Univ. of California, Berkeley, scientists has discovered that a regulatory process that turns on photosynthesis in plants at daybreak likely developed on Earth in ancient, methane-producing microbes 2.5 billion years ago, long before oxygen became available. The research opens new scientific areas in the fields of evolutionary biology and microbiology.
The release of volatile organic compounds from Earth’s forests and smoke from wildfires 3 million years ago had a far greater impact on global warming than ancient atmospheric levels of carbon dioxide, a new Yale Univ. study finds. The research provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change and the relevance of natural components.
Climate researchers in the U.K. have made the world's temperature records available via Google Earth. The new format allows users to scroll around the world, zoom in on 6,000 weather stations, and view monthly, seasonal and annual temperature data more easily than ever before. Users can drill down to see some 20,000 graphs—some of which show temperature records dating back to 1850.