Results 51 to 60 of about 564 (170)

Challenges in modeling the energy balance and melt in the percolation zone of the Greenland ice sheet

Journal of Glaciology, 2023
Increased surface melt in the percolation zone of the Greenland ice sheet causes significant changes in the firn structure, directly affecting the amount and timing of meltwater runoff.
Federico Covi, Regine Hock, Carleen H. Reijmer   +2 more
doaj   +1 more source

Dark Land Surfaces Allow for Refugia That Could Support Photosynthetic Life on the Surface of Snowball Earth

Journal of Geophysical Research: Atmospheres, Volume 131, Issue 13, 16 July 2026.
Abstract Photosynthetic eukaryotic algae survived the Neoproterozoic Snowball Earth events, indicating that liquid‐water refugia existed somewhere on the surface. We examine the potential for refugia at the coldest time of a snowball event, before CO2 had risen and with high‐albedo ice on the frozen ocean, before it became darkened by dust deposition ...
Greta E. M. Shum, Marysa M. Laguë, Abigail L. S. Swann, Cecilia M. Bitz, Edwin D. Waddington, Stephen G. Warren   +5 more
wiley   +1 more source

A synthetic study of acoustic full waveform inversion to improve seismic modelling of firn

Annals of Glaciology, 2022
The density structure of firn has implications for hydrological and climate modelling and for ice shelf stability. The firn structure can be evaluated from depth models of seismic velocity, widely obtained with Herglotz-Wiechert inversion (HWI), an ...
Emma Pearce, Adam D. Booth, Sebastian Rost, Paul Sava, Tuğrul Konuk, Alex Brisbourne, Bryn Hubbard, Ian Jones   +7 more
doaj   +1 more source

A Vast Valley Network Beneath the Greenland Ice Sheet

Geophysical Research Letters, Volume 53, Issue 13, 16 July 2026.
Abstract Mapping subglacial topography along the margin of the Greenland Ice Sheet was revolutionized by reconciling measurements of ice thickness and surface velocity using the principle of mass conservation. Despite evidence that many subglacial valleys resolved by that method extend upstream, it cannot be applied to the ice sheet's slower‐flowing ...
Allison M. Chartrand, Joseph A. MacGregor, Mathieu Morlighem, Olga V. Sergienko, Helen Ockenden, William T. Colgan, Gong Cheng   +6 more
wiley   +1 more source

Revealing firn structure at Dome A region in East Antarctica using cultural seismic noise [PDF]

The Cryosphere
Antarctica is mostly covered by snow, firn, and glacier ice, and the transformation from snow to firn and glacier ice influences energy transfer and material transport in polar regions.
Z. Song, Z. Song, Y. Pan, Y. Pan, J. Li, J. Li, H. Peng, H. Peng, Y. Wang, Y. Wang, Y. Yang, Y. Yang, K. Lu, X. Tang, X. Tang, X. Zhang, X. Zhang, X. Zhang   +17 more
doaj   +1 more source

Hot water drilling in the firn layer of Greenland's percolation zone

Annals of Glaciology, 2021
The intermixed thermal and structural framework of cold firn, water-saturated firn and ice layers in Greenland's percolation zone can be challenging to penetrate with core drills.
Neil Humphrey, Joel Harper, Toby Meierbachtol   +2 more
doaj   +1 more source

Rethinking Alzheimer's Disease Therapy: From Amyloid‐Centric Approaches to Multi‐Target Phytochemical Strategies

Journal of Neurochemistry, Volume 170, Issue 7, July 2026.
Alzheimer's disease is driven by interconnected pathological processes, including amyloid‐β aggregation, tau hyperphosphorylation, neuroinflammation, oxidative stress, synaptic dysfunction, and mitochondrial impairment. While recently approved anti‐amyloid therapies represent an important advance, their modest clinical benefits highlight the ...
Emre Aktaş, İlay Yurt, Yağmur Nisa Cerlet, Haşmet Ayhan Hanağası   +3 more
wiley   +1 more source

Climatic and insolation control on the high-resolution total air content in the NGRIP ice core [PDF]

Climate of the Past, 2016
Because the total air content (TAC) of polar ice is directly affected by the atmospheric pressure and temperature, its record in polar ice cores was initially considered as a proxy for past ice sheet elevation changes. However, the Antarctic ice core TAC
O. Eicher, M. Baumgartner, A. Schilt, J. Schmitt, J. Schwander, T. F. Stocker, H. Fischer   +6 more
doaj   +1 more source

Windblown Diatoms for Reconstructing Westerly Wind Variability in the South Atlantic Sector of the Southern Ocean

Geophysical Research Letters, Volume 53, Issue 12, 28 June 2026.
Abstract Southern Hemisphere westerly winds are important drivers of Antarctic and sub‐Antarctic environmental change. Short observational wind records prevent us from fully understanding the scope of their variability. Proxy records provide valuable tools to extend environmental records. Here we present a novel wind study based on the use of windblown
Dieter R. Tetzner, Elizabeth R. Thomas, Claire S. Allen, Delia Segato, Shaun Miller   +4 more
wiley   +1 more source

Concerning the Deposition and Diagenesis of Strata in Polar Firn [PDF]

Journal of Glaciology, 1988
Abstract Depth hoar in polar firn forms when large temperature gradients act on low-density firn, but high-density firn does not develop into depth hoar. Low densities in firn may be depositional (burial of surface hoar or still-air snowfall) or diagenetic (mass loss to the free atmosphere, typically in autumn); however, diagenesis is
openaire   +1 more source