Sentences with phrase «core oxygen isotope»

Evidence for approximately contemporaneous global cooling in sediments that do contain YTT glass shards has been found in marine core oxygen isotope records from the South China Sea (3), as have terrestrial carbon isotope and pollen records from Northern India and Bengal (23).

Not exact matches

The composition of these ice cores, especially the presence of hydrogen and oxygen isotopes, provides a picture of the climate at the time.

When the jet stream got loopy In order to track the jet stream's behavior thousands of years ago, Bowen and his fellow researchers looked at oxygen isotope ratios from lake cores and cave formations in the eastern and western United States.

The researchers determined from the isotope ratio that the Taylor Glacier samples were 120,000 years old, and validated the estimate by comparing the results to well - dated ice core measurements of atmospheric methane and oxygen from that same period.

To figure out those answers, Rybczynski turned to Ash Ballantyne, another grad student at Duke, who was using oxygen isotopes from tree cores to determine historical temperatures.

The team based its analysis on ratios of oxygen and hydrogen isotopes in ice cores drilled in East Antarctica.

In the past decade, paleoclimatologists have reconstructed a record of climate change over the last millennium by consulting historical documents and examining indicators of temperature change like tree rings, as well as oxygen isotopes in ice cores and coral skeletons.

By measuring the content of the special oxygen isotope O18 in the ice cores, you can get information about the temperature in the past climate, year by year.

The paleoclimate data, which included mainly changes in the oxygen isotopes of the calcium carbonate deposits, were then compared to similar records from other caves, ice cores, and sediment records as well as model predictions for water availability in the Middle East and west central Asia today and into the future.

Then the team restricted evidence to just three measurements that can be obtained from shell samples in sediment cores: cadmium concentration and carbon and oxygen isotope ratios in the calcium carbonate shells.

There are also a number of paleoclimatic recorders of oxygen isotopes, including lake / ocean records, speleothems (in caves), corals, ice cores, etc..

(I think some of Lonnie Thompson's work on interpreting low - latitude oxygen isotope values as temperature signals in ice cores led to some issues).

Sulfate sources and oxidation chemistry over the past 230 years from sulfur and oxygen isotopes of sulfate in a West Antarctic ice core.

Sensitivity of Oxygen Isotopes of Sulfate in Ice Cores to Past Changes in Atmospheric Oxidant Concentrations.

In any event, pretty early on in the book (a bit after box 2.2, «The World According to Oxygen Isotopes») he says: that cores taken from «Intermediate depths in the ocean... show warming of perhaps 5C» and that this warming was caused by CO2 the source of which is still controversial.

There are also a number of paleoclimatic recorders of oxygen isotopes, including lake / ocean records, speleothems (in caves), corals, ice cores, etc..

(I think some of Lonnie Thompson's work on interpreting low - latitude oxygen isotope values as temperature signals in ice cores led to some issues).

In this paper, the authors reconstruct North Atlantic water temperature over the last millennium using oxygen isotopes from ocean sediment cores on the Canadian east coast.

«Oxygen and Carbon Isotope Record of East Pacific Core V19 - 30: Implications for the Formation of Deep Water in the Late Pleistocene North Atlantic.»

«Measurements of oxygen isotopes from the GISP2 ice core suggest the ending of the Younger Dryas took place over just 40 — 50 years in three discrete steps, each lasting five years.

Mike Flynn November 19, 2015 at 9:33 pm «Measurements of oxygen isotopes from the GISP2 ice core suggest the ending of the Younger Dryas took place over just 40 — 50 years in three discrete steps, each lasting five years.

Core PS51 / 038 -3: MIS 6 and MIS 5 (5e) have mainly been identified by oxygen and carbon isotope stratigraphy, paleomagnetostratigraphy, and abundances of planktic foraminifers and coarse fraction (Supplementary Fig. 3) 56.

Now in a Climate of the Past paper, Seltzer et al. present a new record of oxygen isotopes in atmospheric O2 derived from two Antarctic ice cores.

The stratigraphic framework and related age models of the four sediment cores used in this study, are based on oxygen isotope stratigraphy, 10Be stratigraphy, paleomagnetostratigraphy, biostratigraphy, lithostratigraphy, and / or magnetic susceptibility records (Supplementary Figs. 2 — 5).

Core PS2138 - 2: MIS 6 and MIS 5 (5e) have mainly been identified by oxygen isotope stratigraphy, paleomagnetostratigraphy, and the occurrence of benthic foraminifera species Pullenia bulloides (P.b.)(Supplementary Fig. 5) 58, 67, 68.

http://www.agu.org/pubs/crossref/2002/2000PA000571.shtml On the 1470 - year pacing of Dansgaard - Oeschger warm events The oxygen isotope record from the Greenland Ice Sheet Project 2 (GISP2) ice core was reanalyzed in the frequency and time domains.

Broecker used changes in oxygen isotopes in deep - sea cores, analyzed by Emliani during 1955 - 1966, to point out the sawtooth nature of glacial cycles — a slow cooling followed by rapid warming.

These Holocene glacier expansions are consistent with other millennial evidence e.g. treelines moving south, ice core melt and oxygen isotopes.

Global solar irradiance reconstruction [48 — 50] and ice - core based sulfate (SO4) influx in the Northern Hemisphere [51] from volcanic activity (a); mean annual temperature (MAT) reconstructions for the Northern Hemisphere [52], North America [29], and the American Southwest * expressed as anomalies based on 1961 — 1990 temperature averages (b); changes in ENSO - related variability based on El Junco diatom record [41], oxygen isotopes records from Palmyra [42], and the unified ENSO proxy [UEP; 23](c); changes in PDSI variability for the American Southwest (d), and changes in winter precipitation variability as simulated by CESM model ensembles 2 to 5 [43].

A study by Thomas, Dennis et al 2009 [8] derived a high resolution temperature proxy record from oxygen isotope ratios from the ice core.

The Taylor ice core from Antarctica has about half the oxygen isotope range that those in Greenland do.

Prior to this, persistent warmth occurred from 1970 to 1975, a prominent anomaly that has been noted before (Schwerdtfeger 1976; Mosley - Thompson et al. 1991) and is consistent with positive anomalies of atmospheric mass over the Antarctic (Swanson and Trenberth 1981), and with positive oxygen isotope anomalies in West Antarctic ice cores (Mosley - Thompson et al. 1991).

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).

The principal dataset we use is the temporal variation of the oxygen isotope ratio (δ18O relative to δ16O; figure 1a right - hand scale) in the shells of deep - ocean - dwelling microscopic shelled animals (foraminifera) in a near - global compilation of ocean sediment cores [4].

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).

Oxygen isotope and palaeotemperature records from six Greenland ice - core stations temperatures during the Medieval Warm Period (~ AD 800-1100) were about 1 °C warmer than those of the Current Warm Period.

Paleo temperatures from oxygen isotope ratios from the greenland ice cores show that a temperature increase of 0.7 °C will not bring the current temperature up to the level of the Medieval Warm Period let alone the Roman optimum and the MInoan Warm period which were both warmer than the medieval warm period.

A negative trend is also seen in oxygen isotope records in Greenland ice cores (NGRIP - members 2004), which implies that the proxy records from northern Sweden display a general feature of Holocene climate in the North Atlantic region, possibly linked to orbital forcing of summer insolation.

Global, cyclic, decadal, climate patterns can be traced over the past millennium in glacier fluctuations, oxygen isotope ratios in ice cores, sea surface temperatures, and historic observations.

The researchers routinely analyze ice cores for a host of indicators — particulates, dust, oxygen isotopes, etc. — that can paint a picture of past climate in that region.

In the 1970s, the first comprehensive analysis of oxygen isotopes in sediments from cores taken from the sea floor established for the first time that the timing of the Ice Ages was linked to subtle changes in the Earth's orbit around the Sun as suggested long ago by Serbian mathematician Milutin Milankovitch.