نتایج جستجو برای: ice impact

تعداد نتایج: 810821  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2006
V Faye McNeill Thomas Loerting Franz M Geiger Bernhardt L Trout Mario J Molina

Characterizing the interaction of hydrogen chloride (HCl) with polar stratospheric cloud ice particles is essential for understanding the processes responsible for ozone depletion. We studied the interaction of gas-phase HCl with ice between 243 and 186 K by using (i) ellipsometry to monitor the ice surface and (ii) coated-wall flow tube experiments, both with chemical ionization mass spectrome...

Journal: :Proceedings. Biological sciences 2012
Andrew Mellows Ross Barnett Love Dalén Edson Sandoval-Castellanos Anna Linderholm Thomas H McGovern Mike J Church Greger Larson

Previous studies have suggested that the presence of sea ice is an important factor in facilitating migration and determining the degree of genetic isolation among contemporary arctic fox populations. Because the extent of sea ice is dependent upon global temperatures, periods of significant cooling would have had a major impact on fox population connectivity and genetic variation. We tested th...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Michail I Petaev Shichun Huang Stein B Jacobsen Alan Zindler

One explanation of the abrupt cooling episode known as the Younger Dryas (YD) is a cosmic impact or airburst at the YD boundary (YDB) that triggered cooling and resulted in other calamities, including the disappearance of the Clovis culture and the extinction of many large mammal species. We tested the YDB impact hypothesis by analyzing ice samples from the Greenland Ice Sheet Project 2 (GISP2)...

2015
Frans-Jan W Parmentier Wenxin Zhang Yanjiao Mi Xudong Zhu Jacobus van Huissteden Daniel J Hayes Qianlai Zhuang Torben R Christensen A David McGuire

The Arctic is rapidly transitioning toward a seasonal sea ice-free state, perhaps one of the most apparent examples of climate change in the world. This dramatic change has numerous consequences, including a large increase in air temperatures, which in turn may affect terrestrial methane emissions. Nonetheless, terrestrial and marine environments are seldom jointly analyzed. By comparing satell...

2017
A. J. Tedstone P. W. Nienow

We present ice velocities observed with global positioning systems and TerraSAR-X/TanDEM-X in a land-terminating region of the southwest Greenland ice sheet (GrIS) during the melt year 2012–2013, to examine the spatial pattern of seasonal and annual ice motion. We find that while spatial variability in the configuration of the subglacial drainage system controls ice motion at short timescales, ...

2015
Katherine Carpenter Vaibhav Bahadur

Most studies on icephobicity focus on ice formation with pure water. This manuscript presents studies to understand the influence of surfaces on saltwater ice nucleation and propagation. Experiments are conducted to quantify the influence of surface chemistry on saltwater ice nucleation and to understand the utility of superhydrophobic surfaces for saltwater icephobicity. These experiments are ...

2012
C. Hohenegger B. Alali K. R. Steffen D. K. Perovich K. M. Golden

During the Arctic melt season, the sea ice surface undergoes a remarkable transformation from vast expanses of snow covered ice to complex mosaics of ice and melt ponds. Sea ice albedo, a key parameter in climate modeling, is determined by the complex evolution of melt pond configurations. In fact, ice–albedo feedback has played a major role in the recent declines of the summer Arctic sea ice p...

2015
Per S Andersson Vanja Alling Don Porcelli

Ice export from the vast Arctic Siberian shelf is calculated using dO values and salinity data for water samples collected during the International Siberian Shelf Study between August and September 2008 (ISSS-08). The samples represent a wide range of salinities and dO values due to river water inputs and sea ice removal. We estimate the fraction of water that has been removed as ice by interpr...

2017
Astrid Strunk Mads Faurschou Knudsen David L Egholm John D Jansen Laura B Levy Bo H Jacobsen Nicolaj K Larsen

The influence of major Quaternary climatic changes on growth and decay of the Greenland Ice Sheet, and associated erosional impact on the landscapes, is virtually unknown beyond the last deglaciation. Here we quantify exposure and denudation histories in west Greenland by applying a novel Markov-Chain Monte Carlo modelling approach to all available paired cosmogenic 10Be-26Al bedrock data from ...

Journal: :Remote Sensing 2016
Stefan Kern Burcu Ozsoy-Çiçek Anthony P. Worby

Accurate circum-Antarctic sea-ice thickness is urgently required to better understand the different sea-ice cover evolution in both polar regions. Satellite radar and laser altimetry are currently the most promising tools for sea-ice thickness retrieval. We present qualitative inter-comparisons of winter and spring circum-Antarctic sea-ice thickness computed with different approaches from Ice C...

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