Geography & Atmospheric Science: Recent submissions
Now showing items 181-200 of 386
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Transmission of stress between an ice stream and interstream ridge
(International Glaciological Society, 2001-06-01)Measurements of strain rate are used to describe the stress distribution at the lateral margin of an active West Antarctic ice stream. The goal is to describe the way in which drag at the sides operates to control the ... -
Trend surface analysis of Greenland precipitation
(American Geophysical Union, 2001-12-27)Multivariate regression methods are applied to measurements of accumulation covering much of the interior of the Greenland ice sheet to evaluate the important factors that describe the current distribution of accumulation. ... -
Greenland Ice Sheet response to external forcing
(American Geophysical Union, 2001-12-01)Kinematic wave modeling is used to evaluate possible responses of the Greenland ice sheet to changes in its surface mass balance. In the approach followed here the reference state is defined based on measured velocity and ... -
Registering imagery to ICESat data for measuring elevation changes on Byrd Glacier, Antarctica
(American Geophysical Union, 2005-12-07)We present a new approach to derive control information from ICESat data that enables rigorous registration of aerial and satellite imagery. The technique, based on matching terrain features identified from ICESat measurements ... -
ICESat measurements reveal complex pattern of elevation changes on Siple Coast ice streams, Antarctica
(American Geophysical Union, 2005-12-03)We compare ICESat data (2003–2004) to airborne laser altimetry data (1997–98 and 1999–2000) to monitor surface changes over portions of Van der Veen (VdVIS), Whillans (WIS) and Kamb ice streams (KIS) in the Ross Embayment ... -
Bed radar reflectivity across the north margin of Whillans Ice Stream, West Antarctica, and implications for margin processes
(International Glaciological Society, 2006-01-01)Surface-based ice-penetrating radar profiles were made across the active north margin (the Snake) of the upper part of Whillans Ice Stream (formerly Ice Stream B, branch B2), West Antarctica, at three locations. Low frequency ... -
Controls on advance of tidewater glaciers: results from numerical modeling applied to Columbia Glacier
(American Geophysical Union, 2007-07-11)A one-dimensional numerical ice flow model is used to study the advance of a tidewater glacier into deep water. Starting with ice-free conditions, the model simulates glacier growth at higher elevations followed by advance ... -
Subglacial topography and geothermal heat flux: potential interactions with drainage of the Greenland ice sheet
(American Geophysical Union, 2007-06-05)[1] Many of the outlet glaciers in Greenland overlie deep and narrow trenches cut into the bedrock. It is well known that pronounced topography intensifies the geothermal heat flux in deep valleys and attenuates this flux ... -
Fracture propagation as means of rapidly transferring surface meltwater to the base of glaciers
(American Geophysical Union, 2007-01-07)1] Propagation of water-filled crevasses through glaciers is investigated based on the linear elastic fracture mechanics approach. A crevasse will penetrate to the depth where the stress intensity factor at the crevasse ... -
Modeling dynamic controls on ice streams: a Bayesian statistical approach
(International Glaciological Society, 2008-12-05)Our main goal is to exemplify the study of ice-stream dynamics via Bayesian statistical analysis incorporating physical, though imperfectly known, models using data that are both incomplete and noisy. The physical–statistical ... -
Intermittent thinning of Jakobshavn Isbræ, West Greenland, since the Little Ice Age
(International Glaciological Society, 2008-05-05)Rapid thinning and velocity increase on major Greenland outlet glaciers during the last two decades may indicate that these glaciers became unstable as a consequence of the Jakobshavn effect (Hughes, 1986), with terminus ... -
Surface roughness over the northern half of the Greenland Ice Sheet from airborne laser altimetry
(American Geophysical Union, 2009-06-05)Surface roughness, defined as the standard deviation of small-scale elevation fluctuations from the linear trend over 0.5 km, can be estimated from high-resolution airborne laser altimetry. Here we present results for the ... -
Basal melt rates beneath Whillans Ice Stream, West Antarctica
(International Glaciological Society, 2010-08-05)Basal water lubricates and enables the fast flow of the West Antarctic ice streams which exist under low gravitational driving stress. Identification of sources and rates of basal meltwater production can provide insight ... -
A physically based calving model applied to marine outlet glaciers and implications for the glacier dynamics
(International Glaciological Society, 2010-11-05)We present results from numerical ice-flow models that include calving criteria based on penetration of surface and basal crevasses, which in turn is a function of longitudinal strain rates near the glacier front. The ... -
Controls on the recent speed-up of Jakobshavn Isbrae, West Greenland
(International Glaciological Society, 2011-02-05)Jakobshavn Isbrae, West Greenland, underwent a large, rapid and not well understood change in flow dynamics in 1998, leading to a doubling of its ice discharge rates. We calculate the width-averaged forces controlling flow ... -
The response of Petermann Glacier to large calving events and its future stability in the context of atmospheric and oceanic warming
(International Glaciological Society, 2012-11-05)This study assesses the impact of a large 2010 calving event on the current and future stability of Petermann Glacier, Greenland, and ascertains the glacier’s interaction with different components of the climate and ocean ... -
Historical Demographics, Student Origins, and Recruitment at Off-Reservation Indian Boarding Schools, 1900
(University of Kansas, 2014-08-31)Beginning in 1878, the United States government funded the establishment of off-reservation industrial training schools for Native American youth. Much has been written about the histories of the schools, but information ... -
Characterizing synoptic and cloud variability in the Northern Atlantic using self-organizing maps
(University of Kansas, 2014-08-31)Low − level clouds have a significant influence on the Earth's radiation budget and it is thus imperative to understand their behavior within the marine boundary layer (MBL). The cloud properties in the Northeast ... -
An Ephemeral Experience of Place: Growing Up In The Army
(University of Kansas, 2014-08-31)Dependents of U.S. Army military personnel struggle with place perception and connection. These individuals lead nomadic lives relocating every two to three years. The majority of the literature on sense of place stresses ... -
Analysis of MODIS 250 m NDVI Using Different Time-Series Data for Crop Type Separability
(University of Kansas, 2014-08-31)The primary objectives of this research were to: (1) investigate the use of different compositing periods of NDVI values of time-series MODIS 250 m data for distinguishing major crop types on the central Great Plains of ...