Sentences with phrase «isotopic signature of»

What about the isotopic signature of biological carbon as compared with the isotopic signature of fossil carbon is irrelevant to human (fossil fuel led) CO2 increases?

Because the different isotope ratios for the two kinds of plants propagate through the food chain, it is possible determine if the principal diet of a human or other animal consists primarily of C3 plants or C4 plants by measuring the isotopic signature of their collagen and other tissues.

Consider the facts: the climate system is indicated to have left the natural cycle path; multiple lines of evidence and studies from different fields all point to the human fingerprint on current climate change; the convergence of these evidence lines include ice mass loss, pattern changes, ocean acidification, plant and species migration, isotopic signature of CO2, changes in atmospheric composition, and many others.

We assumed only that due to the biological and physical effects the ratio fabsorbed (t) / (total CO2 content of then air) is more or less constant, hence a simple response pulse response exp -LRB-- t / lifetime) is applied to the anthropic time series of coal, gas, oil and cement which have different delta13C As the isotopic signature of (CO2 natural)(t) is slowly decreasing because plants living days or centuries ago are now rotting and degassing and as molecules entered in the ocean decades ago are now in the upwellings after a slow migration along the equal density surface from the high latitudes where those surface are surfacing at depth zero, there are common sense constraints or bounds on the possible evolution of the delta13C of the natural out - gassed CO2 molecules.

a.) Analysis of the Allende meteorite showed that the Solar System formed directly from material that retained the chemical and isotopic signature of supernova debris: http://www.omatumr.com/Data/1975Data.htm

Here, we test a new proxy — the oxygen isotopic signature of individual benthic foraminifera — to detect rapid (i.e. monthly to decadal) variations in deep ocean temperature and salinity in the sedimentary record.

We also know the atmospheric increase is from burning fossil fuels because of the isotopic signature of the carbon in the atmosphere.

Researchers use the isotopic signature of methane to figure out its source.

Scientists must think about which microbes are «making the methane [and] what does that say about the isotopic signature of the methane in the atmosphere,» McCalley told Eos.

Measurement of the 13C isotopic signature of methane emissions from Northern European wetlands.

Comprehending the isotopic signature of fossil fuel loading of the air does not need calculations of nuclear states and decay paths.

Re # 17, it seems that the isotopic signature of atmospheric methane could tell you something about it's source.

WRT the source of the CO2, Brian has already pointed out the isotopic signature of the CO2, but over and above this, we've produced about 2x as much CO2 as has gone into the atmosphere!

We also know the atmospheric increase is from burning fossil fuels because of the isotopic signature of the carbon in the atmosphere.

«Teeth retain the isotopic signature of an individual's diet at various periods of life depending on the tooth type sampled, ranging from in utero to approximately 16 years of age,» the researchers wrote.

The team found that the isotopic signature of bones located at the site changed over time.

«There could be unique biochemistry, because the isotopic signature of the biomass of microorganisms oxidizing methane in freshwater wetlands is different from their marine counterparts.

«Adding neodymium changed that picture and gave us an independent measure of the amount coming from shallow continental waters that carried an isotopic signature of life.»

They found that the isotopic signatures of sulfur (in sulfate), carbon (in dissolved inorganic carbon) and strontium from water samples collected from tributaries adjacent to mountaintop mining sites are distinguishable from those collected from unaffected upstream waters.

Their integration also enables us delineate the initial radium isotopic signatures of the spill waters, indicating the nature of the wastewater that caused the spill.»

Rubenstein analyzed the isotopic signatures of feathers from wintering warblers to reveal the location of their breeding sites.

That scenario has been bolstered by similarities in the isotopic signatures of the asteroids and seawater.

For example, the isotopic signatures of ice cores depend on the seasonal distribution of precipitation.

So, the scientists will need to tease out the extent of those alterations to trace the isotopic signatures of nitric oxide sources accurately.

The study focused on unique isotopic signatures of methane from different sources.

However, the isotopic signatures of CH4 indicated that only AM was active in July (Fig. 3) suggesting that the HM biomass had built up earlier.

Because of these confounding factors, palaeoreconstructions based on the isotopic composition of organic carbon (δ13C) will almost certainly have to be based on the isotopic signatures of organic compounds that can be associated with a single species, or group of physiologically similar species

Not exact matches

Since the reaction produces nitrous oxide with a specific isotopic signature, Joye says: «This could be an easy way to «sniff» around the surface of Mars looking for pockets of subsurface brine that might be hotspots for extreme microbial life.»

But planetary bodies that formed in different parts of the solar system generally have different isotopic compositions, so different that the isotopic signatures serve as «fingerprints» for planets and meteorites from the same body.

That helped narrow down the sources, Schaefer says, because different types of wetlands have different isotopic signatures.

Animals that live in the sea have ratios of carbon and nitrogen isotopes that differ from those found in terrestrial animals, and this isotopic signature is passed on to the people who eat them.

Based on measurements of Jupiter and the solar wind, which are thought to preserve the hydrogen isotopic ratio of the protosolar nebula, scientists think nebular water had an extremely light hydrogen isotopic signature — much closer to what the Baffin Island lavas suggest about the deep mantle's water.

Because the tiny zircon crystals retain their isotopic signatures despite episodes of remelting, the researchers could date their cores at 0.8 million to 2.1 million years old.

The results, published online today in Science, reveal that the inclusions have a much lighter isotopic signature than does the ocean, suggesting that the composition of seawater has indeed evolved over time.

These gases would be carried away in the atmosphere after an explostion and investigators could look for the isotopic signatures thousands of kilometers away from the test site and even months afterward.

They measured and analyzed the samples for inorganic contaminants and to identify the unique isotopic signature, or fingerprint, of Bakken region brines.

To test this hypothesis, the possible contribution of marine fish in the diet of these carnivores was evaluated using carbon, nitrogen and sulphur isotopes in faunal bone collagen, comparing these isotopic signatures between predators and their potential prey.

The scientists analyzed the samples» isotopic ratios — a telltale chemical signature of what the animals ate during their lifetimes.

Isotope geochemist Mukul Sharma of Dartmouth College in Hanover, New Hampshire, says he has been unable to find any significant amount of platinum - group elements with the distinctive isotopic signature showing that they came from space.

The tracers, which have been tested both in the laboratory and the field, are based on the distinctive isotopic and geochemical signatures of two elements, boron and strontium, found in coal ash effluent.

Peter Weber is a member of the Chemical & Isotopic Signatures group.

And then, if the ocean surface water was «diluted» with isotopic light melt water, would this not be reflected with a similar drop in the Greenland ice cores, just by a changing isotope signature of the source, instead of a temperature drop?

«Using more sophisticated physics and powerful super-computers, we managed to remove the systematic biases that plague traditional modeling and have previously led to false identifications of the 6Li / 7Li isotopic signature.»

And then, if the ocean surface water was «diluted» with isotopic light melt water, would this not be reflected with a similar drop in the Greenland ice cores, just by a changing isotope signature of the source, instead of a temperature drop?

[Response: If the rise in atmospheric CO2 at the end of the last glacial time had come from organic carbon (trees, peat, dissolved organic matter in the ocean) or especially methane (which is even more isotopically «light» than CO2) it would have left an isotopic signature.

However, from an isotope signature point of view the methane hydrate source works according to Zeebe, who told me:» I'm still convinced that this methane hydrate hypothesis is working very well in terms of total amount of carbon and in terms of the isotopic signature that we see.

Methane release alters the tiny shells of «forams» and leaves a distinctive isotopic signature that can be examined my scientists.

Isotopic signatures can be used to date past events of methane release, as well as their duration.

Its isotopic signature is depleted in the carbon - 13 isotope, which explains why the atmospheric ratio of carbon - 12 to carbon - 13 has been going down as anthropogenic carbon dioxide goes up.

The statement that only 55 % of human CO2 emissions have been removed by the biosphere / biosphere is something you'll have to prove, which is hard because as far as I'm aware human CO2 does not posses an isotopic signature that can be easily differentiated from natural sources — the arguments you often hear on Skeptical Science are measurements in changes of the C12 / C13 / C14 atmospheric mass, not individual CO2 molecules, which can be misleading.