Sentences with phrase «atmospheric gases at»

In the experiment, cosmic radiation was passed through a large reaction chamber containing a mixture of lower atmospheric gases at realistic concentrations that was exposed to ultraviolet radiation from lamps that mimic the action of the sun's rays.

The team then used these data to calculate the difference between the speed of the atmospheric gas at different positions on the star and the average speed over the entire star.

Not exact matches

We know that contained in these ice layers there are bubbles of atmospheric gases, particulate matter and other distince indicators of the climate at the time the layers were formed.

A switch to natural gas won't do Kenneth Caldeira, an atmospheric scientist at the Carnegie Institution for Science, said EPA's actions have to be the first step, and the agency needs to take similar steps every two years or so.

The reaction rate between atmospheric hydrogen chloride (HCl) and chlorine nitrate (ClONO2) is greatly enhanced in the presence of ice particles; HCl dissolves readily into ice, and the collisional reaction probability for ClONO2 on the surface of ice with HCl in the mole fraction range from ∼ 0.003 to 0.010 is in the range from ∼ 0.05 to 0.1 for temperatures near 200 K. Chlorine (Cl2) is released into the gas phase on a time scale of at most a few milliseconds, whereas nitric acid (HNO3), the other product, remains in the condensed phase.

But advances in the understanding of atmospheric oxygen levels are challenging that idea, explains Sandra Schachat, a paleoentomologist at Stanford University, who led a recent study that modeled the gas's availability during the hexapod gap.

«Which of those is correct at this stage is unknown, but the droughts being driven by atmospheric greenhouse gas concentrations is in line with some of these global circulation models,» Lewis said.

The study shows, with 90 percent confidence, that such extreme summers in Australia are five times more likely due to an increase in greenhouse gases, said paper co-author David Karoly, an atmospheric scientist at the University of Melbourne and the Australian Research Council Center of Excellence for Climate System Science.

Already, atmospheric levels of carbon dioxide, the leading greenhouse gas, are approaching 400 ppm, and at least the amount of warming caused by that level is likely by century's end.

The takeaway is that if humanity stopped cranking out greenhouse gases immediately, sea levels would still rise for centuries before the heat dissipates through Earth's atmosphere and into space, says study co-author Susan Solomon, an atmospheric scientist at MIT.

The ice core data also shows that CO2 and methane levels have been remarkably stable in Antarctica — varying between 300 ppm and 180 ppm — over that entire period and that shifts in levels of these gases took at least 800 years, compared to the roughly 100 years in which humans have increased atmospheric CO2 levels to their present high.

When the researchers placed the material inside a gas chamber and cranked up the air pressure from one bar (about the atmospheric pressure at sea level) to five bars, the cube's volume increased by about 3 percent.

The researchers looked at a total of 34 different global climate model outputs, encompassing different degrees of atmospheric sensitivity to greenhouse gases and different levels of human emissions of greenhouse gases into the atmosphere.

A few molecules of H2O at normal atmospheric pressure are solid when below 32 degrees Fahrenheit, liquid between 32 °F and 212 °F, and gas when above 212 °F.

Already, atmospheric concentrations of just CO2 have reached 400 ppm at times and all greenhouse gases put together are now at 430 ppm.

To verify emissions from the San Juan and Four Corners coal - fired power plants, the Los Alamos team deployed ground - based solar spectrometers and point sensors to measure atmospheric concentrations of gases at a site close to these power plants.

The atmospheric concentration of carbon dioxide, a critical greenhouse gas, is higher than it has been for at least 650,000 years.

On May 9, instruments atop Hawaii's Mauna Loa volcano pegged the atmospheric concentration of carbon dioxide (CO2)-- the gas that contributes most to global warming — at slightly above 400 parts per million (ppm).

John Cushman, Purdue University distinguished professor of earth, atmospheric and planetary science and a professor of mathematics, is commercializing a technology that could provide an «instantly rechargeable» method forelectric and hybrid vehicle batteries through a quick and easy process similar to refueling a car at a gas station.

Like the other gas giants, Saturn lacks a solid surface that can be used to measure its rotation period; surficial atmospheric features at the equator move faster than at the poles.

«We're trying to figure out how to deal with the greenhouse gas problem» says Sarah Doherty, an atmospheric scientist at the University of Washington in Seattle and co-author of the study.

Detlev Helmig, an atmospheric chemist and group leader at the Institute of Arctic and Alpine Research laboratory at the University of Colorado, Boulder, has spent 10 years studying the strange ups and downs of gases in the atmosphere.

«If we want natural gas to be the cleanest fossil fuel source, methane emissions have to be reduced,» says Gabrielle Pétron, an atmospheric scientist at NOAA and at the University of Colorado in Boulder, and first author on the study, currently in press at the Journal of Geophysical Research.

The production of the gas is nearly doubling every year, says Michael Prather, atmospheric chemist at University of California, Irvine, who had predicted earlier this year that emissions would likely exceed the industry's claim that only 2 percent of the gas is released into the atmosphere.

At the same time, even if California meets its ambitious target, it may not make a huge dent in the atmospheric concentrations of greenhouse gases causing climate change.

Their findings have been recently published in EPJ D and are particularly relevant for the development of novel applications in medicine, health care and materials processing because they involve air at normal atmospheric pressure, which would make it cheaper than applications in inert gases or nitrogen.

«The atmospheric and oceanic CO2 increase is being driven by the burning of fossil fuels,» says Pieter Tans, a senior scientist at the National Oceanic and Atmospheric Administration's Earth System Research Laboratory, who leads the U.S. government effort to monitor global greenhouse gas levels.

Cutting - edge techniques enabled the researchers to detect the presence of gases even at part - per - trillion levels, one million times less concentrated than atmospheric CO2 concentrations.

«We are beginning to see the links in a chain that begins with solar - driven processes acting on gas in the upper atmosphere and leads to atmospheric loss,» said Bruce Jakosky, MAVEN principal investigator with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder.

In February 2018, the average atmospheric carbon dioxide level was 408 parts per million at Mauna Loa, Hawaii, site of National Oceanic and Atmospheric Administration global greenhouse gas monitoring.

Although atmospheric oxygen soon recovered again as photosynthesis and weathering reached a new balance, at about 10 per cent of present - day levels, the oxidative weathering of sulphides on land filled the oceans with sulphate which created abundant food for a group of bacteria that filled the oceans with sewer gas (hydrogen sulphide) toxic to oxygen - loving lifeforms (delaying the development of eukaryotic plants and animals) and turned them «into stinking, stagnant waters almost entirely devoid of oxygen.»

With a larger sample, planets at varying stages of atmospheric loss will be found that confirm whether or not the majority of close in rocky planets are the burnt embers leftover of gas giants who ventured to close to their host stars.

At the same time, the burning of ever - increasing quantities of coal, oil and natural gas converts some atmospheric nitrogen into oxides of nitrogen (NOx).

The preliminary results of this study have been on our website since the time the flooding happened, but now we have looked not only at the rainfall, but also the influence of anthropogenic greenhouse gas emissions on the atmospheric circulation and how this propagates from rainfall, to river flow down to the direct impact of flooded houses in the river catchment zones.

In 2003, astronomers at the University of Texas at Arlington performed refined calculations to determine that the habitable zone around 47 Ursae Majoris, where an inner rocky planet (with suitable mass and atmospheric gas composition and density) can have liquid water on its surface, lies between 1.05 and 1.83 AUs of the star.

The small Delta age at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the \ «bipolar seesaw \».

It was at that time that atmospheric greenhouse gas concentrations stopped following the periodic pattern of the Milankovitch cycles.

IFE's Low Pressure Loop is used for studying 2 - and 3 - phase multiphase gas - liquid - particle flow in near horizontal pipes or in a rectangular channel, at atmospheric pressure.

Now, giant cyclones at the planet's poles have been seen in greater detail than ever before — they are not only stunning, but unique from atmospheric storms of any other planet in the Solar System, even other gas and ice giants.

For example, changes in Earth's atmospheric composition (especially the concentrations of greenhouse gases) may alter the climate, while climate change itself can change the atmospheric composition (for example by changing the rate at which weathering removes CO2).

Atmospheric scientists measure the amount of CH4 gas in the atmosphere and use these data, along with models of atmospheric transport, to estimate the amount of CH4 released at Earth's surface.

A 2008 study led by James Hansen found that climate sensitivity to «fast feedback processes» is 3 °C, but when accounting for longer - term feedbacks (such as ice sheet disintegration, vegetation migration, and greenhouse gas release from soils, tundra or ocean), if atmospheric CO2 remains at the doubled level, the sensitivity increases to 6 °C based on paleoclimatic (historical climate) data.

The ARM Aerosol Measurement Science Group (AMSG) coordinates ARM Climate Research Facility observations of aerosols and atmospheric trace gases with user needs to ensure advanced, well - characterized observational measurements and data products — at the spatial and temporal scales necessary — for improving climate science and model forecasts.

Then the scientists divided the «atmospheric» spectrum by the star's «clean» spectrum to determine the gas composition and density of the atmosphere at different altitudes, as well as temperatures.

In one study, Mao and colleagues subjected a mixture of hydrogen and water to a pressure of about 220 megapascals (2,000 times atmospheric pressure) at room temperature (300 K or 80 °F), which formed a clathrate hydrate — a cage - like framework of water molecules enclosing molecules of gas.

We find (i) measurements at all scales show that official inventories consistently underestimate actual CH4 [methane] emissions, with the natural gas and oil sectors as important contributors; (ii) many independent experiments suggest that a small number of «super-emitters» could be responsible for a large fraction of leakage; (iii) recent regional atmospheric studies with very high emissions rates are unlikely to be representative of typical natural gas system leakage rates; and (iv) assessments using 100 - year impact indicators show system - wide leakage is unlikely to be large enough to negate climate benefits of coal - to - natural gas substitution.

Ferenc Miskolczi, an atmospheric physicist at NASA's Langley Research Center with three decades of experience, had found that researchers have been repeating a mistake when calculating the impact of greenhouse gas emissions on temperatures.

if the numbers of animals that are raised for human purposes remains relatively constant, the atmospheric greenhouse gas load doesn't change at all from this source.

If we knew ocean heat uptake as well as we know atmospheric temperature change, then we could pin down fairly well the radiative imbalance at the top of the atmosphere, which would give us a fair indication of how much warming is «in the pipeline» given current greenhouse gas concentrations.

Geoengineering proposals fall into at least three broad categories: 1) managing atmospheric greenhouse gases (e.g., ocean fertilization and atmospheric carbon capture and sequestration), 2) cooling the Earth by reflecting sunlight (e.g., putting reflective particles into the atmosphere, putting mirrors in space to reflect the sun's energy, increasing surface reflectivity and altering the amount or characteristics of clouds), and 3) moderating specific impacts of global warming (e.g., efforts to limit sea level rise by increasing land storage of water, protecting ice sheets or artificially enhancing mountain glaciers).