Sentences with phrase «ice bubble co2»

Not exact matches

Scientists can determine ancient atmospheric concentrations by measuring CO2 and methane levels in tiny air bubbles trapped in such ice, formed when the ice fell to the earth as snow.

Which leads me to another question — the melting glacial / Greenland / Antarctic ice water is depleted in CO2 (check out the bubbles in your ice cubes)-- how much additional CO2 is being sequestered by this runoff into the oceans, and what happens to CO2 increase when we run out of glaciers?

These measurements, supplemented by analyses of air bubbles trapped in ice core samples, show unequivocally that atmospheric CO2 has increased from a pre-industrial level of 277 ppm in 1750 to present day concentrations that are approaching 390 ppm.

Stomata data show a much larger variation of CO2 in the last millenium (besides higher values in general), in part caused by the smoothing effect of relative slow closing air bubbles in ice cores...

We don't really know the magnitude of that lag as well as Barton implies we do, because it is very challenging to put CO2 records from ice cores on the same timescale as temperature records from those same ice cores, due to the time delay in trapping the atmosphere as the snow is compressed into ice (the ice at any time will always be younger older than the gas bubbles it encloses, and the age difference is inherently uncertain).

This means glacier meltwater has a higher concentration of CO2 and as it trickles down through the ice layers modifies the ice bubbles as Jaworowski explained in his presentation to the US Senate Committee (March 2004).

And they included measurements of CO2 in air from the firn from the surface to the closing depth of the air bubbles in the ice, again with different equipment.

The average closing period was 8 years, thus the ice core CO2 in the bubbles is an average of 8 years of CO2 levels.

Ice - core CO2 measurements are direct measurements on air that has been enclosed in bubbles.

We know from bubbles of air trapped in ice cores that before the industrial revolution, the amount of CO2 in the air was approximately 280 parts per million (ppm).

For periods before 1958, CO2 levels are determined from air bubbles trapped in polar ice cores.

But it is a proxy, because the idea that that it is not a proxy rests on the tenuous and unproven assumption that the chemical composition of the ice - core data does not undergo any fractionation processes before closing and after closing that affect the chemical composition of the bubbles thereby perfectly preserving the atmospheric concentration of CO2.

Ice core CO2 is directly measured in the bubbles, that is not a proxy.

Also, given the atmospheric CO2 measurements at South Pole range between 246.59ppm - 521.48 ppm I don't see how the trapped CO2 in the ice - core bubbles could accurately represent the back - ground level.

In 1996, Etheridge e.a. refuted most of the objections against ice cores by drilling three ice cores at Law Dome, measuring CO2 in firn and still open pores and closed bubbles in ice at closing depth.

At closing depth, direct in - situ measurements of CO2 in firn, thus of still open bubbles, and from ice, thus already fully closed bubbles, via the normal route of drilling ice, transport, crushing under vacuum, measuring the levels, both show the same CO2 levels.

There is contamination of the air in the bubble by water; different results are obtained if the ice is crushed or melted to obtain the air sample; it takes decades for the air bubble to form; the raw data was smoothed out by a 70 year moving average that removed the great annual variability found in the 19th century and Stomata Index (SI) records; closer examination revealed a major flaw in the hypothesis because temperature rises before CO2.

MEANWHILE, as the climate mafia propagandisers inside their COLD = HOT bubble, the other conveniently forgotten pole, Antarctica, continues its long 40 year + cooling trend, gaining ice mass despite record and rising CO2 levels and claims of «The Hottest Years Evah ``...

«Until 1985, the published CO2 readings from the air bubbles in the pre-industrial ice ranged from 160 to about 700 ppmv, and occasionally even up to 2,450 ppmv.

He said scientists have been able to correlate changes in atmospheric temperature with changes in levels of carbon dioxide going back more than 500,000 years by analyzing ice core samples and the CO2 bubbles trapped inside.

you drill an ice core, you break the bubbles, take the CO2 out and measure the concentration..».

Also, regarding subsea volacanic eruptions — a volcanic eruption involves release of magma at several thousand degrees C plus superheated gases — when that hits cold sea water you are going to have a very violent and explosive change of form from lquid water to steam combined with the release of dissolved gases (mostly CO2)-- I am not sure what laws of Chemistry and Physics you are looking at, but I would suggest that that those bubbles and heated gases and water will rise to to the surface very quickly and have a major local effect on any nearby ice.

The scenario presented here is in contrast to [CO2] records reconstructed from air bubbles trapped in ice, which indicate lower concen - trations and a gradual, linear increase of [CO2] through time.»

CO2 trends for earlier times have been derived from measurements of CO2 in air trapped in bubbles in polar ice and in mountain glaciers.

Equilibration with bubbles and clathrates means net migration of CO2 in ice across concentration gradients.

In fact, they did not measure CO2 directly in gas samples taken from inside bubbles (quite possible with modern analytical methods), but rather CO2 released from bubbly ice using a dry cold needle ice crusher.

For example, ice cores taken in various locations around the world (Greenland and Antarctica, for example) are excellent proxies; gas bubbles containing CO2 trapped in ancient ice can be measured, and the age can be determined very accurately (by counting the seasonal ice layers, or measuring the isotope levels of oxygen).

I have repeatedly pointed out (in several places including WUWT) that (1) ice core data are useful because they indicate CO2 concentration and isotope - derived temperature data from the same trapped gas bubbles but (2) ice core data are NOT a direct indication of anything because (2a) different ice cores provide different indications and (2b) other proxies (e.g. stomata data) provide different indications to those of the ice cores and to each other.

The validity of measurement of CO2 from bubbles in ice cores has been challenged in a number of studies.

If the liquid water subsequently freezes, the excess CO2 will appear as very tiny trapped bubbles, far smaller than the size of the ice grains resulting from crushing the ice sample during the analysis process.

These and other problems mean that measurement of CO2 in ice cores is not straight forward — measurement of CO2 concentrations in ice bubbles and determination of the age of the air are likely to be quite variable.

The paper, «Reconstruction of past atmospheric CO2 concentrations by ice core analysis», acknowledges that, due to impurities, liquid water can exist as low as -50 deg C. Diffusion of CO2 into this water, due to its far higher solubility than nitrogen and oxygen, will partially deplete the CO2 from trapped air bubbles.

Micro bubbles found in deep polar ice cores of the ancient atmosphere (1 - 200,000 years ago) showed a higher atmospheric density than now, perhaps 2 atmospheres, also higher water vapor and CO2.

It is not that I am failing to think logically, it is when people start talking about he compression of ice relative to air bubbles relative to the porosity of said ice and the amount of time it takes for that ice to seal when looking at the time scale of CO2 found in ice samples, I am pretty well lost.

CO2 Concentrations: record of global CO2 concentration for the last 1000 years, derived from measurements of CO2 concentration in air bubbles in the layered ice cores drilled in Antarctica (blue line) and from atmospheric measurements since 1957.

Figure 1: Antarctic (Vostok) ice core records of temperature, CO2 (upper) and CH4 (lower) including time - scale adjustment to account for ice - gas age difference associated with the time for air bubbles to be sealed (Petit et al. 1999) and corrected for variations of climate in the water vapor source regions (Vimeux et al. 2002) as described in Supporting Text of Hansen and Sato (2004).