Results 11 to 20 of about 314,168 (203)
Texture of Polar Firn for Remote Sensing [PDF]
Annals of Glaciology, 1987 Knowledge of the texture of polar firn is necessary for interpretation of remotely sensed data. We find that dry polar firn is an irregularly stratified, anisotropic medium. Grains in firn may be approximated as prolate spheroids with average axial ratios as high as 1.2 or greater and with a preferred orientation of long axes clustered around the ...
R.B. Alley
core +5 more sources
Kinematic waves in polar firn stratigraphy [PDF]
Journal of Glaciology, 2011 AbstractRadar studies of firn on the ice sheets have revealed complex folds on its internal layering that form from the interplay of snow accumulation and ice flow. A mathematical theory for these fold structures is presented, for the case where the radar cross section lies along the ice-flow direction and where the accumulation rate and ice-flow ...
Ng, F., King, E.C.
openaire +6 more sources
Critical porosity of gas enclosure in polar firn independent of climate [PDF]
Climate of the Past, 2017 In order to interpret the paleoclimatic record stored in the air enclosed in polar ice cores, it is crucial to understand the fundamental lock-in process.
C. F. Schaller +3 more
doaj +2 more sources
Modeling enhanced firn densification due to strain softening [PDF]
The Cryosphere, 2022 In the accumulation zone of glaciers and ice sheets snow is transformed into glacial ice by firn densification. Classically, this process is assumed to solely depend on temperature and overburden pressure, which is controlled by the accumulation rate ...
F. M. Oraschewski +2 more
doaj +1 more source
The Community Firn Model (CFM) v1.0 [PDF]
Geoscientific Model Development, 2020 Models that simulate the evolution of polar firn are important for several applications in glaciology, including converting ice-sheet elevation change measurements to mass change and interpreting climate records in ice cores.
C. M. Stevens +8 more
doaj +1 more source
Polar firn properties in Greenland and Antarctica and related effects on microwave brightness temperatures [PDF]
The Cryosphere, 2023 In studying the mass balance of polar ice sheets, fluctuations in firn density near the surface is a major uncertainty. In this paper, we explore these variations at locations on the Greenland Ice Sheet and at the Dome C location in Antarctica.
H. Xu +6 more
doaj +1 more source
Pure rotational Raman spectroscopy applied to N2/O2 analysis of air bubbles in polar firn
Journal of Glaciology, 2021 Earlier gas measurements of firn air (atmosphere in open pore channels) at polar sites have revealed the occurrence of gas fractionation phenomena during bubble close-off, in addition to well-known thermal and gravitational gas separation.
Hiroshi Ohno +2 more
doaj +1 more source
Modelling of the densification of polar firn: characterization of the snow–firn transition [PDF]
Annals of Glaciology, 1998 The transformation of dry snow to firn is described by the transition between densification by deformationless restacking and densification by power-law creep. The observed decrease with temperature of the density at the snow-firn transition seems to result from the competition between grain-boundary sliding and power-law creep. These two densification
Arnaud, Laurent +4 more
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Impact of physical properties and accumulation rate on pore close-off in layered firn [PDF]
The Cryosphere, 2014 Investigations into the physical characteristics of deep firn near the lock-in zone through pore close-off are needed to improve understanding of ice core records of past atmospheric composition. Specifically, the permeability and microstructure profiles
S. A. Gregory, M. R. Albert, I. Baker
doaj +1 more source
Atmosphere, 2020 Understanding how physical characteristics of polar firn vary with depth assists in interpreting paleoclimate records and predicting meltwater infiltration and storage in the firn column.
Ian E. McDowell +3 more
doaj +1 more source