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Dynamics of Ice Streams: A Physical Statistical Approach

Listed in NASA Earthdata CMR

Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets.

Description

Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood.

Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice sheets. In this project, physical statistical models are used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, the Northeast Ice Stream in Greenland will be investigated.

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Geophysical models lie at the core of the approach, but are embellished by statistical modeling of various components of variability. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project, new observational data collected using remote-sensing techniques are used.

The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these are combined mathematically into a physical statistical model that yields the posterior distributions for basal and surface elevations, surface velocity fields, and stress fields, conditional on the data. Inference based on these distributions is carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.

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Inferred from text
Climate change science 73% · Longitudinal study 65%
Provenance · 1 source records, 16 field assertions
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NASA Earthdata CMRC1214586540-SCIOPS14 d agoJSON v1
FieldAssertionExtractorEvidence
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concepts[measured_variable].gcmd:earth-science/cryosphere/glaciers-ice-sheets/glacier-elevation-ice-sheet-elevationsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/cryosphere/glaciers-ice-sheets/glacier-motion-ice-sheet-motionsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/cryosphere/snow-ice/ice-motionsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/cryosphere/snow-ice/ice-velocitysource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/land-surface/topography/terrain-elevationsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/terrestrial-hydrosphere/glaciers-ice-sheets/glacier-elevation-ice-sheet-elevationsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[method].local:method:longitudinal-studyenrichment · NASA CMRkeyword-concept-rules@1.0.0title+description (65%)
concepts[platform].gcmd_platform:dhc-6source · NASA CMRconnector:nasa_cmr@1.0.0
descriptionsource · NASA CMRconnector:nasa_cmr@1.0.0/umm/Abstract
license_textsource · NASA CMRconnector:nasa_cmr@1.0.0
spatialsource · NASA CMRconnector:nasa_cmr@1.0.0/umm/SpatialExtent
temporalsource · NASA CMRconnector:nasa_cmr@1.0.0/umm/TemporalExtents
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