Sentences with phrase «during glacial climate»

He thinks that we can look to paleoclimate as evidence for abrupt climate change — and indeed we can — but the examples he has to use are those of abrupt change during deglaciation (YD) or during glacial climate (D - O; Heinrich; Bond).

However, the global dust burden and associated radiative forcing are substantially higher during glacial climates, so that the amplification of the dust load by this feedback is larger.

Not exact matches

Climate scientists find the last glacial period interesting because ice cores in Greenland and ocean sediment cores have shown that during this period there were sharp shifts in global temperatures.

So the fact that we have this very strong drying in the tropics during glaciation would argue for a strong feedback of water vapor concentration to the global climate during glacial - interglacial cycles.»

Using climate models to understand the physical processes that were at play during the glacial periods, the team were able to show that a gradual rise in CO2 strengthened the trade winds across Central America by inducing an El Nino - like warming pattern with stronger warming in the East Pacific than the Western Atlantic.

The results of our recent study suggest that the Atlantic water never ceased to flow into the Nordic Seas during the glacial period,» says Mohamed Ezat, PhD at Centre for Arctic Gas Hydrate, Environment and Climate (CAGE) at UiT, The Arctic University of Norway.

It seems that after the climate cooled during the last glacial period, disappearing habitat inland forced brown bears toward the coasts, where they encountered polar bears shifted there by British - Irish ice sheets.

Ice core records are rich archives of the climate history during glacial - interglacial cycles over timescales of up to ~ 800 kyr before the current age.

Similar fluctuations in OMZ intensity have occurred during the Dansgaard - Oeschger (D - O) events (millennial - scale abrupt climate oscillations) during the last glacial period (Cannariato and Kennett, 1999; Schmittner et al., 2007).

The archaeological record suggested that very roughly 150,000 individuals spanned Europe and Asia, living in small groups of 15 to 25 — and that their total numbers fluctuated greatly during the several climate cycles (which included harsh glacial periods) that occurred during the half a million years they inhabited Earth, before going extinct 40,000 years ago.

Blunier, T. and E. J. Brook, 2001: Timing of millennial - scale climate change in Antarctica and Greenland during the last glacial period.

Some unknown natural forcing exists with a period of 1470 yrs, and the climate system is subject to stochastic resonance during glacials.

The kind of switch operating during glacial periods, leading to D - O events, is unlikely to work in a warm climate with relatively little ice.

Aren't the neo-glacial readvances and other signs of a cooling climate during the past 3,000 years evidence of a gradual return to glacial conditions (prior to the anthropogenic influence brought on by the industrial revolution)?

The following is a link to Bond's paper «Persistent Solar influence on the North Atlantic Climate during the Holocene» Bond track 22 cycles through the Holocene interglacial and into the Wisconsin glacial period.

IN FACT IT IS WELL KNOWN THAT DURING GLACIAL PERIODS THE CLIMATE WAS MUCH DRYER, AND DURING WARMER PERIODS MUCH WETTER.

Second, the idea that there might be a lag of CO2 concentrations behind temperature change (during glacial - interglacial climate changes) is hardly new to the climate science community.

Melting of glacial ice could play an important role in maintaining water security during times of drought or similar climate extremes, the committee noted.

* It would take only a small further reduction in climate forcing (less long - lived GHGs or whatever) to yield more ice during the glacial phase of glacial - interglacial oscillations.

A new research paper by Friedrich et al. looks at glacial - interglacial climate variability during the last 784,000 years to estimate Earth's climate variability.

Strong evidence from ocean sediment data and from modelling links abrupt climate changes during the last glacial period and glacial - interglacial transition to changes in the Atlantic Ocean circulation.

Similarly, a colder climate with generally decreased humidity q O could be closer to the critical threshold, which might be the reason for less - stable monsoon circulations during glacial periods.

Pepin, L., Raynaud, D., Barnola, J. M. & Loutre, M. F. Hemispheric roles of climate forcings during glacial — interglacial transitions as deduced from the Vostok record and LLN - 2D model experiments.

Arctic climatic extremes include 25 °C hyperthermal periods during the Paleocene - Eocene (56 — 46 million years ago, Ma), Quaternary glacial periods when thick ice shelves and sea ice cover rendered the Arctic Ocean nearly uninhabitable, seasonally sea - ice - free interglacials and abrupt climate reversals.

The climate record obtained from two long Greenland ice cores reveals several brief climate oscillations during glacial time.

Both panels are reconstructions of oxygen concentrations in the California Margin during a cold, glacial climate (left, 18,000 years ago) and a warm, interglacial climate (right, 14,000 years ago; Moffitt et al. 2015a).

By extrapolating from its radiative forcing in the current climate, we estimate that dust reduces precipitation during glacial times by as much as half the reduction due to the colder climate alone.

The emergence of civilization during our current interglacial, the Holocene, has been attributed to the «relative climate quiescence» of this period relative to the massive, abrupt shifts in climate that characterized glacial periods in the form of D - O events.»

The 25 D - O events during the last glacial, where temperatures rose and fell by 5 to 10 degrees C (10 - 15 degrees C for Greenland) within a span of decades that were «explained by internal variability of the climate system alone ``, deemed global in scale, and they occurred without any changes in CO2 concentrations, which stayed steady at about 180 ppm throughout the warming and cooling.

«During the last glacial / interglacial transition the Earth's climate underwent abrupt changes around 14.6 kyr ago.

---- Mayewski, 2016 http://meetingorganizer.copernicus.org/EGU2016/EGU2016-2567.pdf «The demonstration using Greenland ice cores that abrupt shifts in climate, Dansgaard - Oeschger (D - O) events, existed during the last glacial period has had a transformational impact on our understanding of climate change in the naturally forced world.

This type of behavior is especially evident during transitions from glacial to interglacial conditions, when climate is affected by a wide variety of time - varying influences and is relatively unstable.

Müller, J. & Stein, R. High - resolution record of late glacial and deglacial sea ice changes in Fram Strait corroborates ice - ocean interactions during abrupt climate shifts.

26) During the current interglacial the solar and oceanic cycles are broadlyoffsetting one another to reduce overall climate variability but during glacial epochs they broadly supplement one another to produce much larger climate sDuring the current interglacial the solar and oceanic cycles are broadlyoffsetting one another to reduce overall climate variability but during glacial epochs they broadly supplement one another to produce much larger climate sduring glacial epochs they broadly supplement one another to produce much larger climate swings.

Dansgaard — Oeschger events (often abbreviated D — O events) are rapid climate fluctuations that occurred 25 times during the last glacial period.

This case appears to be based on recent research taking two different approaches: looking at recent climate changes, and changes during the Last Glacial Maximum (LGM) about 20,000 years ago.

Paleo - climate research suggests the position of the ASL also shifts between glacials and interglacials, and drove warm CDW shoreward during interglacials and accelerated glacier retreat.

The ubiquitous character of certain events further confirms their importance: «the Younger Dryas and a large number of abrupt changes during the last ice age called Dansgaard / Oeschger events (23 abrupt changes into a climate of near - modern warmth and out again, during the last glacial period) have been corroborated in multiple ice cores from Greenland, Antarctica and tropical mountains, marine sediments from the North Atlantic Ocean, the tropical Atlantic, eastern Pacific, and Indian Oceans, and from various records on land.

The PalMod project is funded by the Federal Ministry of Education and Science (BMBF) to understand climate system dynamics and variability during the last glacial cycle.

Ominously, data showed that sudden climate shifts did not happen only during a glacial period.

This is supported by multiple lines of evidence, including GCMs, paleoclimate evidence (including climate response to forcing during glacial periods as well as millennial proxies), the instrumental record, and the climate response to volcanic forcings among others.

2) Warm or cold is irrelevant because it was during a transition between two quasi-stable climate regimes (glacial: interglacial) where all forcings (including Milankovitch and cosmic rays) were made irrelevant by strong positive albedo feedback.

The climate during glacial periods is quite different and the moisture could be brought from lower latitudes by the atmosphere.

Recent Earth history has featured quasi -100,000-y, glacial − interglacial climate cycles with lower / higher temperatures and greenhouse gas concentrations during glacials / interglacials.

Using measured amounts of GHGs during the past 800000 years of glacial — interglacial climate oscillations and surface albedo inferred from sea - level data, we show that a single empirical «fast - feedback» climate sensitivity can account well for the global temperature change over that range of climate states.

Climate response and radiative forcing from mineral aerosols during the last glacial maximum, pre-industrial, current and doubled - carbon dioxide climates

Our record shows that CO2 variations during the glacial period have a clear relationship with abrupt climate changes in the Northern Hemisphere that continues into the deglacial period.

Here we briefly discuss the radiative forcing estimates used for understanding climate during the last millennium, the mid-Holocene and the Last Glacial Maximum (LGM)(Section 9.3) and in estimates of climate sensitivity based on palaeoclimatic records (Section 9.6.3).

Related Volcanoes, Tree Rings, and Climate Models: This is how science works Fossil Focus: Using Plant Fossils to Understand Past Climates and Environments Atmospheric oxygen over Phanerozoic time Coupled carbon isotopic and sedimentological records from the Permian system of eastern Australia reveal the response of atmospheric carbon dioxide to glacial growth and decay during the late Palaeozoic Ice Age

I think there must be at least two factors interacting to achieve the necessary switches so that they offset one another to minimise climate variability during interglacials but supplement one another to increase climate variability during glacial periods.