Results 81 to 90 of about 795 (198)
Journal of Geophysical Research: Atmospheres, Volume 131, Issue 4, 28 February 2026.Abstract Nitrogen stable isotopes (δ15N) of ice core nitrate (NO3−) are often subject to diverse interpretations associated with changes in nitrogen oxide (NOx) sourcing, atmospheric reactions, and/or post‐depositional processes. Here, an ice core from Mont Blanc (French Alps) was analyzed to investigate the δ15N(NO3−) record over the past 1,000 years.
Alexis Lamothe +11 more
wiley +1 more source
Titan's Plains Revealed: Evidence for a Layered Surface
Journal of Geophysical Research: Planets, Volume 131, Issue 2, February 2026.Abstract Undifferentiated plains are the most common terrain type on Titan, yet their composition and geologic history remain poorly understood. To better characterize their physical properties, we combined Cassini RADAR measurements from nadir altimetry and side‐looking SAR modes. We analyzed these data using radar backscatter models, finding that the
A. Fine +3 more
wiley +1 more source
Diffusion of stable isotopes in polar firn and ice : the isotope effect in firn diffusion
Diffusion of stable isotopes in polar firn and ice : the isotope effect in firn diffusionInternational Symposium on Physics of Ice Core Records. Shikotsukohan, Hokkaido, Japan, September 14-17, 1998.
Johnsen, Sigfús. J. +6 more
openaire +2 more sources
Frontiers in Earth Science, 2020 The role of near-surface snow processes for the formation of climate signals through densification into deep polar firn is still barely understood. To this end we have analyzed a shallow snow pit (0-3 meters) from EastGRIP (Greenland) and derived high ...
Maurine Montagnat +6 more
doaj +1 more source
On the Rates of Growth of Grains and Crystals in South Polar Firn [PDF]
Journal of Glaciology, 1969 The size of firn crystals as a function of age has been investigated in thin sections to a depth of 49 m at the South Pole. Grain cross-sections increased in size from 0.24 mm2 at 0.1 m depth to 0.63 mm2 at 10 m. Crystals, as distinct from grains, increased in size from 0.18 to 0.43 mm2 over the same interval, implying that grains are generally ...
openaire +1 more source
Kinetic grain growth in firn induced by meltwater infiltration on the Greenland Ice Sheet [PDF]
The CryosphereThe microstructure of polar firn governs its porosity, permeability, and compaction rate, and is thus critical to understanding surface elevation change, heat and gas exchange, and meltwater infiltration on ice sheets.
K. L. Gehl, J. T. Harper, N. F. Humphrey
doaj +1 more source
Modeling heat, mass, and species transport in polar firn [PDF]
Annals of Glaciology, 1996 A finite-element model for simulating multi-dimensional air flow with heat, mass and chemical species transport through firn is discussed. The model is applied to an investigation of near-surface layering effects on ventilation rates. Field measurements of permeability at Summit, Greenland, are presented that show that permeability varies by at least a
openaire +1 more source
20th century trends and budget implications of chloroform and related tri-and dihalomethanes inferred from firn air [PDF]
Atmospheric Chemistry and Physics, 2006 Four trihalomethane (THM; CHCl3, CHBrCl2, CHBr2Cl and CHBr3) and two dihalomethane (DHM; CH2BrCl and CH2Br2) trace gases have been measured in air extracted from polar firn collected at the North Greenland Icecore Project (NGRIP) site.
D. R. Worton +5 more
doaj
Spatial distribution of vertical density and microstructure profiles in near-surface firn around Dome Fuji, Antarctica [PDF]
The CryosphereTo better understand the near-surface evolution of polar firn in low-accumulation areas (<30 mm w.e. yr−1), we investigated the physical properties – density, microstructural anisotropy of ice matrix and pore space, and specific surface area (SSA ...
R. Inoue +13 more
doaj +1 more source