Sentences with phrase «ice cores indicates»

Comparison with the CO2 levels measured in air extracted from ice cores indicates that the current concentrations are higher than they have been in at least 800,000 years (see Question 6).

Ice cores indicate that a cold planet was mostly covered with deserts (plenty of dust).

The δ18O profile of the Upper Fremont Glacier (UFG) ice core indicates a change in climate known as the Little Ice Age (LIA)....

Temperatures in Antarctica do not change as much as the ice cores indicate.

Therefore the fire scar evidence fails to record the Roman Warm Period, which the ice cores indicate was even warmer than the MWP.

Data extracted from tree rings and Antarctica ice cores indicate that solar activity has indeed fallen to unusually low levels at least three times during the past one thousand years, each drop corresponding to a long, cold spell of roughly a century in duration.

Greenland ice cores indicate that the start of the instrumented data (thermometers) coincides with a cold period in the northern hemisphere and that at the site of a well - studied ice core (Global Cooling - Doomsday Called Off), the temperature in the mid 1800s was the coldest in 8,000 years.

Not exact matches

For instance, in the Tropics the temperature variations were three times as intense as today at the height of the last glacial, whereas the ice cores from Greenland indicate variations that were 70 times as intense.

Why do some ice core samples seem to indicate CO2 spikes trailed increases in global temperature?

Gard found similar fossils deeper down in the sediment cores, indicating that the Arctic ice partially cleared at various times from about 128 000 to 71 000 years ago — a period covering the latest interglacial and the early part of the latest ice age.

For example see figure 1 in Alley's paper that shows the GISP2 ice core data (The wiggle lines indicate a massive increase in sea salt and dust that is being transported to the Greenland Ice sheet, as compared to the current climaice core data (The wiggle lines indicate a massive increase in sea salt and dust that is being transported to the Greenland Ice sheet, as compared to the current climaIce sheet, as compared to the current climate.

Regional averages are defined as: Antarctica, annual for inland ice cores; tropical Indian Ocean, annual for 15 ° S to 15 ° N, 50 ° E to 100 ° E; and North Atlantic Ocean, July to September for 42 ° N to 57 ° N, 35 ° W to 20 ° E. Grey shading indicates the range of observed proxy estimates of regional cooling: Antarctica (Stenni et al., 2001; Masson - Delmotte et al., 2006), tropical Indian Ocean (Rosell - Mele et al., 2004; Barrows and Juggins, 2005), and North Atlantic Ocean (Rosell - Mele et al., 2004; Kucera et al., 2005; de Vernal et al., 2006; Kageyama et al., 2006).

Note that other large eruptions occurred during the last 600 years, according to tree ring and ice core data, but are not indicated here because the source volcano is unknown (e.g. 1809).

Assuming an iron - rich planet with an internal structure like Earth, modelling results for the first discovered super-Earth (GJ 876 d) indicate the existence of a threshold in planetary diameter above which a super-Earth «most certainly» has a high water content (an «ocean planet» or «water world,» where thick layers of water and pressurized ice surround a rocky mantle and core); this threshold was found to be around 24,000 kilometers (or nearly 15,000 miles) in the particular case of GJ 876 d (Valencia et al, 2007).

Note that other large eruptions occurred during the last 600 years, according to tree ring and ice core data, but are not indicated here because the source volcano is unknown (e.g. 1809).

This data clearly indicates that the planet is getting warmer, and this correlates with increased greenhouse gases, both now and in the distant past (as verified by ice core samples).

The interactions (feedbacks) between THC shifts and sea ice and glacial calving (as indicated by ice - rafted debris in deep sea core records) would tend to seriously magnify the climate changes compared to what would be expected from a similar THC shift today.

Combined climate / ice sheet model estimates in which the Greenland surface temperature was as high during the Eemian as indicated by the NEEM ice core record suggest that loss of less than about 1 m sea level equivalent is very unlikely (e.g. Robinson et al. (2011).

For example see figure 1 in Alley's paper that shows the GISP2 ice core data (The wiggle lines indicate a massive increase in sea salt and dust that is being transported to the Greenland Ice sheet, as compared to the current climaice core data (The wiggle lines indicate a massive increase in sea salt and dust that is being transported to the Greenland Ice sheet, as compared to the current climaIce sheet, as compared to the current climate.

There are many direct proxies like ice cores that indicate much warmer periods in the past on the 4,000 and 11,000 year scales.

The Vostok core clearly indicates that when the temperature reaches 2 °C a mechanism kicks in which sets the temperature falling again and initiates an ice - age.

Recent evidence from ice - core drilling in Greenland indicates that similar fluctuations also occurred during the previous interglacial period, possibly due to rapid changes in ocean circulation.

Ice core data suggest that the Greenland Summit region was ice - covered during this period, but reductions in the ice sheet extent are indicated in parts of southern GreenlaIce core data suggest that the Greenland Summit region was ice - covered during this period, but reductions in the ice sheet extent are indicated in parts of southern Greenlaice - covered during this period, but reductions in the ice sheet extent are indicated in parts of southern Greenlaice sheet extent are indicated in parts of southern Greenland.

Ice core observations indicate ice during the last interglacial at sites (white dots), Renland (R), North Greenland Ice Core Project (N), Summit (S, GRIP and GISP2) and possibly Camp Century (C), but no ice at sites (black dots): Devon (De) and Agassiz (Ice core observations indicate ice during the last interglacial at sites (white dots), Renland (R), North Greenland Ice Core Project (N), Summit (S, GRIP and GISP2) and possibly Camp Century (C), but no ice at sites (black dots): Devon (De) and Agassiz core observations indicate ice during the last interglacial at sites (white dots), Renland (R), North Greenland Ice Core Project (N), Summit (S, GRIP and GISP2) and possibly Camp Century (C), but no ice at sites (black dots): Devon (De) and Agassiz (ice during the last interglacial at sites (white dots), Renland (R), North Greenland Ice Core Project (N), Summit (S, GRIP and GISP2) and possibly Camp Century (C), but no ice at sites (black dots): Devon (De) and Agassiz (Ice Core Project (N), Summit (S, GRIP and GISP2) and possibly Camp Century (C), but no ice at sites (black dots): Devon (De) and Agassiz Core Project (N), Summit (S, GRIP and GISP2) and possibly Camp Century (C), but no ice at sites (black dots): Devon (De) and Agassiz (ice at sites (black dots): Devon (De) and Agassiz (A).

For example, he shows an ice core and indicates it is from Antarctica and shows evidence of a change due to the Clean Air Act amendments in the US; the core was actually, as I understand it, from Greenland — and on his visit to see the core, the scientist had shown him cores from both the Antarctic and Greenland Ice Sheeice core and indicates it is from Antarctica and shows evidence of a change due to the Clean Air Act amendments in the US; the core was actually, as I understand it, from Greenland — and on his visit to see the core, the scientist had shown him cores from both the Antarctic and Greenland Ice SheeIce Sheets.

[36][37] Estimates vary for when the last time the Arctic was ice free: 65 million years ago when fossils indicate that plants existed there to as few as 5,500 years ago; ice and ocean cores going back 8000 years to the last warm period or 125,000 during the last intraglacial period.

Dust trapped in polar ice cores shows that ejected material spread around the globe, indicating that the eruption injected substantial material into the stratosphere, where it can strongly affect climate.

And as said before, the ice cores measurements at one side and the emissions estimates for the period 1900 - 1960 indicates that nature was a net sink over that period, be it that in some years nature might have been a source, in other years a sink.

Sediment cores the team collected by drilling in front of the current Cosgrove Ice Shelf indicate that relatively warm ocean waters dissolved the vast ice shelf and even some of the glacier behind it about 2000 years ago, they recently reportIce Shelf indicate that relatively warm ocean waters dissolved the vast ice shelf and even some of the glacier behind it about 2000 years ago, they recently reportice shelf and even some of the glacier behind it about 2000 years ago, they recently reported.

The Etheridge ice core data of CO2 indicate that CO2 was below average in the 17th and 18th centuries by a few ppm.

This is based on the ice core record, but there are other measures of CO2 that strongly disagree with the ice core record: for example, the leaf stomata record generated by Wagner et al shows significant variation in the Holocene period, indicating that rapid fluctuations do occur and that 370ppm is «high» but not outside typical variability.

«Ice cores with sufficient vertical resolution (time resolution) have provided 420,000 years of data from Antarctica indicating that the temperature changes preceded the corresponding CO2 changes.

The AMO during the Little Ice Age was characterized by a quasi-periodicity of about 20 years, while the during the Medieval Warm Period the AMO oscillated with a period of about 45 to 65 years... The observed intermittency of these modes over the last 4000 years supports the view that these are internal ocean - atmosphere modes, with little or no external forcing... However, the geographic variability of these periodicities indicated by ice core data is not captured in model simulations.&raqIce Age was characterized by a quasi-periodicity of about 20 years, while the during the Medieval Warm Period the AMO oscillated with a period of about 45 to 65 years... The observed intermittency of these modes over the last 4000 years supports the view that these are internal ocean - atmosphere modes, with little or no external forcing... However, the geographic variability of these periodicities indicated by ice core data is not captured in model simulations.&raqice core data is not captured in model simulations.»

That is, the opposite sequence of events to what the ice core records indicate for interglacial periods of the past 650k years.

However, the geographic variability of these periodicities indicated by ice core data is not captured in model simulations.»

Clearly, the new ice core data indicates that natural climate variations caused huge temperature variations in the past.

We could rewrite orkneylad's post thus — «Clearly, the new ice core data indicates that natural climate variations caused huge temperature variations in the past.

The Vostok ice cores seem to indicate the latter.

Temperature proxy from four ice cores for the last 140,000 years, clearly indicating the greater magnitude of the D - O effect in the northern hemisphere.

Another aspect that seems to be neglected to date is that ice core data may indicate a too low CO2 value because of the presence of CO2 fixing bacteria (see Table 1 in Christner et al.).

This indicates to me that at the very least, the ice core samples were contaminated before they were analysed.

Ice core measurements of beryllium indicate a less variable TSI while modelling from solar magnetic flux show a greater decrease in TSI during the Maunder Minimum.

Note that regional proxies, such as the oxygen - isotope temperature reconstructions from the Greenland Ice Core Project that record Dansgaard - Oeschger events, often indicate faster regional rates of climate change than the overall global average for glacial - interglacial transitions, just as today warming is more pronounced in Arctic regions than in equatorial regions (Barnosky et al., 2003; Diffenbaugh and Field, 2013).

For earlier times, we adopt Greenland temperature estimated as follows (33): For the period 128,700 B.P. to 340,000 B.P., this temperature was derived from a proxy based on Antarctic ice core methane data using the relation T = − 51.5 + 0.0802 [CH4 (ppb)-RSB- from a linear regression of Greenland temperature estimates on Antarctic methane for the period 150 B.P. to 122,400 B.P.. For the remaining period of 122,400 B.P. to 128,700 B.P., data from a variety of climate archives indicate that Greenland warming lags that of Antarctica, with rapid warming commencing around 128.5 ky B.P. in the northern North Atlantic and reaching full interglacial levels by about 127 ky B.P. (51).

It is my contention that the quiescence of CO2 levels, as indicated by the ice core data, indicates that the CO2 regulatory system is a fast one.

Yet, the ice core measurements also indicate a level of stability which is in conflict with the assertion of substantial human influence.

The reconstruction is based on the modulation potential derived from the 10Be records from the Greenland Ice core Project.Red dotted lines indicate the estimated error bars of the reconstruction.

All of this implies that the early Law Dome results of Etheridge are uncharacteristic of CO2 behavior over long times in ice cores, and should not be relied upon to indicate long term accuracy.

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.

Ice core data indicate that average Arctic temperatures at that time were 5.7 to 9.5 deg.