Results 41 to 50 of about 7,958 (231)

The impact of ice layers on gas transport through firn at the North Greenland Eemian Ice Drilling (NEEM) site, Greenland [PDF]

The Cryosphere, 2014
Typically, gas transport through firn is modeled in the context of an idealized firn column. However, in natural firn, imperfections are present, which can alter transport dynamics and therefore reduce the accuracy of reconstructed climate records.
K. Keegan, M. R. Albert, I. Baker
doaj   +1 more source

Seismic observations of a complex firn structure across the Amery Ice Shelf, East Antarctica

Journal of Glaciology, 2021
We use seismic refraction data to investigate the firn structure across a suture zone on the Amery Ice Shelf, East Antarctica, and the possible role of glacier dynamics in firn evolution.
Hannes Hollmann, Adam Treverrow, Leo E. Peters, Anya M. Reading, Bernd Kulessa   +4 more
doaj   +1 more source

Ambient high-frequency seismic surface waves in the firn column of central west Antarctica

Journal of Glaciology, 2022
Firn is the pervasive surface material across Antarctica, and its structures reflect its formation and history in response to environmental perturbations.
Julien Chaput, Rick Aster, Marianne Karplus, Nori Nakata   +3 more
doaj   +1 more source

A Micro-Mechanical Model for the Transformation of Dry Polar Firn Into Ice Using the Level-Set Method

Frontiers in Earth Science, 2020
Interpretation of greenhouse gas records in polar ice cores requires a good understanding of the mechanisms controlling gas trapping in polar ice, and therefore of the processes of densification and pore closure in firn (compacted snow).
Kévin Fourteau, Fabien Gillet-Chaulet, Patricia Martinerie, Xavier Faïn   +3 more
doaj   +1 more source

Nitrate stable isotopes and major ions in snow and ice samples from four Svalbard sites [PDF]

, 2015
Increasing reactive nitrogen (N-r) deposition in the Arctic may adversely impact N-limited ecosystems. To investigate atmospheric transport of N-r to Svalbard, Norwegian Arctic, snow and firn samples were collected from glaciers and analysed to define ...
Aanes R., Alina Marca, Amoroso A., Atkin O.K, Beaudon E., Beine H.J., Björkman M.P, Björkman M.P., Björkman M.P., Blunier T., Bottenheim J.W., Brimblecombe P., Burkhart J.F., Carmen P. Vega, Carroll M.A., Casciotti K.L., Coplen T.B., Dibb J.E., Dickson L.G, Draxler R.R., Elisabeth Isaksson, Eneroth K., Felix J.D., Forsström S., Freyer H.D, Freyer H.D., Førland E.J., Gibbons J.D., Goto-Azuma K., Hastings M.G, Hastings M.G., Hastings M.G., Heaton T.H.E, Heaton T.H.E., Hisdal V, Honrath R.E., Honrath R.E., Jan Kaiser, Jarvis J.C., Kahl J.D.W., Kaiser J., Kang S., Kekonen T., Kühnel R., Kühnel R., Li D., Liu S.C., Mats P. Björkman, Michalski G., Morin S., Morin S., Morin S., Morin S., Mosier A.R., Nuth C., Pohjola V.A., Rickard Pettersson, Rinnan R., Ruggirello R.M., Röthlisberger R., Samyn D., Schuler T.V., Semb A., Shaver G.R., Stohl A., Tõnu Martma, Vega C.P., Veijo A. Pohjola, Wolff E.W, Xu L.   +69 more
core   +2 more sources

Dispersion in deep polar firn driven by synoptic-scale surface pressure variability [PDF]

The Cryosphere, 2016
Commonly, three mechanisms of firn air transport are distinguished: molecular diffusion, advection, and near-surface convective mixing. Here we identify and describe a fourth mechanism, namely dispersion driven by synoptic-scale surface pressure ...
C. Buizert, J. P. Severinghaus
doaj   +1 more source

Gas isotope thermometry in the South Pole and Dome Fuji ice cores provides evidence for seasonal rectification of ice core gas records [PDF]

The Cryosphere, 2022
Gas isotope thermometry using the isotopes of molecular nitrogen and argon has been used extensively to reconstruct past surface temperature change from Greenland ice cores. The gas isotope ratios δ15N and δ40Ar in the ice core are each set by the amount
J. D. Morgan, C. Buizert, T. J. Fudge, K. Kawamura, K. Kawamura, K. Kawamura, J. P. Severinghaus, C. M. Trudinger   +7 more
doaj   +1 more source

Spatial Distribution of Crusts in Antarctic and Greenland Snowpacks and Implications for Snow and Firn Studies

Frontiers in Earth Science, 2021
The occurrence of snowpack features has been used in the past to classify environmental regimes on the polar ice sheets. Among these features are thin crusts with high density, which contribute to firn stratigraphy and can have significant impact on firn
Alexander H. Weinhart, Sepp Kipfstuhl, Maria Hörhold, Olaf Eisen, Olaf Eisen, Johannes Freitag   +5 more
doaj   +1 more source

Transformation process observations of polar firn to ice [PDF]

Annals of Glaciology, 1993
The transformation of snow to ice under compressive stress is a very slow process unless meltwater is present. A qualitative measure of permeability variation with depth was continuously determined for various shallow-ice cores from the dry-snow zones in both Greenland and Antarctica to investigate this transformation process.
Langway, C.C. jr., Shoji, H., Mitani, A., Clausen, Henrik B.   +3 more
openaire   +1 more source

From atmospheric water isotopes measurement to firn core interpretation in Adélie Land: a case study for isotope-enabled atmospheric models in Antarctica [PDF]

The Cryosphere, 2023
In a context of global warming and sea level rise acceleration, it is key to estimate the evolution of the atmospheric hydrological cycle and temperature in polar regions, which directly influence the surface mass balance of the Arctic and Antarctic ice ...
C. Leroy-Dos Santos, C. Leroy-Dos Santos, E. Fourré, C. Agosta, M. Casado, A. Cauquoin, M. Werner, B. Minster, F. Prié, O. Jossoud, L. Petit, A. Landais   +11 more
doaj   +1 more source