Sentences with phrase «in ice core studies»

In ice core studies, the accurate and precise dating of the core samples is a central issue that must be investigated to better constrain the timing, sequence, and duration of past climatic events.

Not exact matches

«In any case, the results of our model study give a clear indication that the bipolar variability of sulfate deposits must be taken into consideration if the traces of large volcanic eruptions are to be deduced from ice cores,» says Dr. Krüger, «Several research groups that deal with this issue have already contacted us to verify their data through our model results.»

Tas van Ommen and Vin Morgan of the Australian Antarctic Division studied snowfall records in ice cores from East Antarctica's Law Dome.

All measurements of lead and other chemicals used in this study were made using DRI's continuous ice core analytical system.

Additional ice cores were contributed to the study by international collaborators including the British Antarctic Survey, the Australian Antarctic Division and the Alfred Wegener Institute in Germany.

«The ice cores obtained through international collaborations were critical to the success of this study in that they allowed us to develop records from parts of Antarctica not often visited by U.S. - based scientists,» said co-author Tom Neumann of NASA's Goddard Space Flight Center in Greenbelt, Maryland, who participated in a Norway - U.S. traverse that collected several of the cores used in this study.

The two ice cores from Denali benefited from high levels of snowfall, providing what Osterberg says is «amazing reproducibility» of the climate record and giving the researchers exceptional confidence in the study results.

Meanwhile striking news came from studies of ancient climates recorded in Antarctic ice cores.

«That is very exciting because a lot of interesting things happened with Earth's climate prior to 800,000 years ago that we currently can not study in the ice core record.»

«Ice cores only tell you about temperatures in Antarctica,» Shakun notes of previous studies that relied exclusively on an ice core from Antarctica that records atmospheric conditions over the last 800,000 yeaIce cores only tell you about temperatures in Antarctica,» Shakun notes of previous studies that relied exclusively on an ice core from Antarctica that records atmospheric conditions over the last 800,000 yeaice core from Antarctica that records atmospheric conditions over the last 800,000 years.

Most previous Antarctic ice core records have not included many of the elements and chemical species that we study, such as heavy metals and rare earth elements, that characterize the anomaly — so in many ways these other studies were blind to the Mt. Takahe event.»

It is set to mark the internationalisation of the program, with fifteen American, Russian, Chinese, Brazilian, Swedish, Japanese, German, Swiss, Italian and French scientists specialising in the study of ice cores due to attend.

The sediment cores used in this study cover a period when the planet went through many climate cycles driven by variations in Earth's orbit, from extreme glacial periods such as the Last Glacial Maximum about 20,000 years ago, when massive ice sheets covered the northern parts of Europe and North America, to relatively warm interglacial periods with climates more like today's.

«Ice cores contain little air bubbles and, thus, represent the only direct archive of the composition of the past atmosphere,» says Hubertus Fischer, an experimental climate physics professor at the University of Bern in Switzerland and lead author of the study.

The study, by an international team of scientists led by the University of Cambridge, examined how changes in ocean currents in the Atlantic Ocean were related to climate conditions in the northern hemisphere during the last ice age, by examining data from ice cores and fossilised plankton shells.

In 1959, the U.S. Army Corps of Engineers built the subterranean city under the guise of conducting polar research — and scientists there did drill the first ice core ever used to study climate.

The new evidence has the potential to alter perceptions about which planets in the universe could sustain life and may mean that humans are having an even greater impact on levels of CO2 in Earth's atmosphere than accepted evidence from climate history studies of ice cores suggests.

The simple fact is that every scientist now involved in climate science, from the study of isotope ratios in deep ice cores to the emission of methane from tropical forests, is not only a scientist, but a political commentator and activist.

Severinghaus discovered that xenon and krypton are well preserved in ice cores, which provides the temperature information that can then be used by scientists studying many other aspects of the earth's oceans and atmosphere over hundreds of thousands of years.

Professor Colin Waters, who led the study, said: «Of the 65 «golden spikes» of the Geological Time Scale currently ratified, all but one are located in strata that accumulated on the sea floor, the one exception being the ice core used to define the base of the Holocene Epoch.

Such fellowships have enabled Antarctic scientists to participate in a range of significant research including using ice cores to determine proxies for the Southern Annular Mode, a molecular study of Antarctic ostracods, and investigating particulate carbon and biogenic silica in sea ice in both the Arctic and Antarctic regions.

«Most ice cores are collected from the middle of the ice sheet where it rarely ever melts, or on the ice sheet edge where the meltwater flows into the ocean,» Karina Graeter, the lead author of the study as a graduate student in Dartmouth's Department of Earth Sciences, said in a statement.

More recent studies, with much more precise correlation between ice cores and global temperature records, have shown that temperature and CO2 changed synchronously in Antarctica during the end of the last ice age, and globally CO2 rose slightly before global temperatures.

Amidst the continuous chatter in the blogosphere about the strengths and limitations about «multiproxy» studies, these studies may be a refreshing return to simpler methods relying on just one type of «proxy»: data from ice cores.

Not to mention that we KNOW levels of CO2 are higher than they have been in hundreds of thousands of years, and data from dendrochronology and ice core studies prove that high levels of CO2 are correlated with higher temperatures.

The best studies we have use dendrochronology and ice core chemical composition to tell us about how CO2 levels and warming are related in the long term.

The study I am citing is Alley and Anandakrishnan, 1995, «Variations in melt - layer frequency in the GISP2 ice core: implications for Holocene summer temperatures in central Greenland» published in the Annals of Glaciology for establishing the long - term frequency of melt events at Summit, Greenland.

Paleoclimate studies of tropical ice cores tend to support the scenario of changes in the tropics propagating northwards, too, not the reverse.

Startlingly, the Greenland ice core evidence showed that a massive «reorganization» of atmospheric circulation in the Northern Hemisphere coincided with each temperature spurt, with each reorganization taking just one or two years, said the study authors.

The lag between movements in temperature and movements in CO2 levels may even between 800 — 1000 years if Vostok ice core studies are correct.

Meanwhile important news came from studies of ancient climates recorded in Antarctic ice cores, retrieved by a French and Russian team from one of the most inhospitable places on Earth.

The sudden onset and ending of the Younger Dryas has been studied in particular detail in the ice core and sediment records on land and in the sea (e.g., Bjoerck et al., 1996), and it might be representative of other Heinrich events.

To carry out the study, the researchers developed a new sample extraction and mass spectrometry method that allowed them to precisely measure the carbon isotopic composition of methane in very small ice core samples.

Every Ice Age high amounts of H2 18 O are found in ceratain shellfish in ocean core studies on the ocean's floor.

Since the hockey stick paper in 1998, there have been a number of proxy studies analysing a variety of different sources including corals, stalagmites, tree rings, boreholes and ice cores.

Scientists extract ice cores from ice sheets and ice caps, studying them to learn about past changes in Earth's climate.

Study: Ammonium as ice core proxy shows strong Medieval Warm Period in the tropics.

Study of the ice core recovered by Russian scientists from deep Antarctic holes has revealed that in the last 450,000 years the Earth has had at least four peaks of temperature upsurge with fluctuations of 10 to 12 degrees.

Russian researchers made this discovery while studying ice cores recovered from the depth of 3.5 kilometres in Antarctica.

We will interpret recently completed measurements of 35 chemical - proxies in the ice - core and relate these to similar studies in other Arctic ice cores, such as by using real - world contaminant transport to validate atmospheric circulation models and chemical - signature sourcing.

Despite multiple careful studies, uncertainties in the ice — gas age differences for the Vostok ice core remain of the order of 1 kyr.

Ice core studies in Greenland and Antarctica have shown that Earth's climate can change abruptly, more like flipping a switch than slowly turning a dial.

Precision of Ice Core Measurements: Some of the best data we have of historic temperatures are the studies of isotopes of gases and various components of the atmosphere in ice cores, such as Vostok in Antarctica, and GRIP in GreenlaIce Core Measurements: Some of the best data we have of historic temperatures are the studies of isotopes of gases and various components of the atmosphere in ice cores, such as Vostok in Antarctica, and GRIP in Greenlaice cores, such as Vostok in Antarctica, and GRIP in Greenland.

Modern Arctic sea ice concentrations and location of sediments cores discussed in this study.

221 A well - written account of Hans Oeschger «s study of fluctuations seen in the ice cores can be found in Thomas Levenson, Ice Times (Harper & Row 1989), chapterice cores can be found in Thomas Levenson, Ice Times (Harper & Row 1989), chapterIce Times (Harper & Row 1989), chapter 3.

A 2015 study using regional ice core data reveals no unusual temperature changes but an exceptional 30 % increase in snow accumulation during the twentieth century, again supporting Zwally's analysis of mass gain in interior west Antarctica.

Ironically / coincidentally, the 2nd speaker on the USACE «I am the corps» video studies «ice core samples in order to predict future climate change.»

Carbon dioxide is best studied in bubbles from Antarctic cores, where the ice is fewer potential contaminants than ice from Greenland; in general, see Alley (2000), p. 103.

Interpretation of such proxy records of climate — for example, using tree rings to judge occurrence of droughts or gas bubbles in ice cores to study the atmosphere at the time the bubbles were trapped — is a well - established science that has grown much in recent years.

There was a study last year using salt content in the Law Dome ice core to produce a 1000 year high resolution ENSO proxy.