Abstract:
The data set was produced for the work detailed in 'The response of ice sheets to climate variability' by K Snow et al (2017, Geophys Research Letters). A coupled ice sheet-ocean model is configured in an idealised setting with an inland-deepening bedrock, forced by far-field hydrographic profiles representative of the Amundsen Sea continental shelf. Similar to observed variability, the thermocline depth in the far-field is moved up and down on various times scales as detailed in the publication, with periods ranging from 2 to ~50 years. Bedrock elevation is provided, and annual melt rate and ice thickness (or sub-annual for short time scales) is provided as well for each forcing period. In addition, similar experiments were carried out with an ice-only model with parameterised forcing. These outputs are provided too.
Keywords:
coupled modelling, cryosphere, grounding line, ice sheet variability, ice shelves
Goldberg, D., & Snow, K. (2017). Transient marine ice sheet response to temporally varying forcing (Version None) [Data set]. Polar Data Centre; British Antarctic Survey, Natural Environment Research Council; Cambridge, CB3 0ET, UK.. https://doi.org/10.5285/abbe3bbb-fb2b-416b-9ba2-12a0f914bac8
| Use Constraints: | Data released under Open Government Licence V3.0: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ |
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| Creation Date: | 2017-11-13 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
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| Parameters: |
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| Personnel: | |
| Name | Dr Petra ten Hoopen |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Ms Kate Snow |
| Role(s) | Investigator |
| Organisation | The Australian National University |
| Name | Dr Daniel Goldberg |
| Role(s) | Investigator |
| Organisation | University of Edinburgh |
| Parent Dataset: | N/A |
| Reference: | Snow Kate et al (2017) Geophysical Research Letters, in press | |
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| Quality: | No "cleaning" was involved. The accuracy is subject to the ability of the model to approximate the differential equations solved, and the ability of the differential equations solved to represent reality, both of which issues have been discussed extensively in the literature (e.g. Durran et al (1999), Numerical Methods for Fluid Dynamics:with Applications in Geophysics, Springer). | |
| Lineage: | The data is 'raw' output of the Massachusetts Institute of Technology general circulation model (MITgcm; mitgcm.org). In each model run the diagnostics tool output yearly the temporal average of various diagnostics, including those provided, over the preceding year. The runs were done using version c66j, with the addition of the changes described in Snow K et al (2017, Geophys Research Letters) as well as Jordan J et al (2017, JGR-Oceans, doi:10.1002/2017JC013251). All relevant parameters given in the supplement of Snow K et al (2017, Geophys Research Letters). The files are in Network Common Dataform (netcdf) format. A model output is provided for each experiment. There are 4 different types of experiment: COUPLED: output from synchronously coupled runs UNCOUPLED_SYM: ice model-only with a transversely symmetric depth-dependent parameterised melt as detailed in Snow K et al (2017, Geophys Research Letters) UNCOUPLED_ASYM: ice model-only with a transversely asymmetric depth-dependent parameterised melt as detailed in Snow K et al (2017, Geophys Research Letters) SLOW: ice model-only with a transversely symmetric depth-dependent parameterised melt as detailed in Snow K et al (2017, Geophys Research Letters), and elevated basal drag and in order to yield a slower-flowing ice sheet and shelf A different file exists for each experiment with naming convention [EXPT TYPE]_[PERIOD_IN_YEARS]_YEAR.nc, with the addition of a single file for each expt type: [EXPT_TYPE]_CONST_FORCING.nc in which all external forcing is time-independent. Dimensions of these files are: X (orthogonal horizontal coordinate in meters) Y (orthogonal horizontal coordinate in meters) time (years) NB: as detailed in Snow K et al (2017, Geophys Research Letters), the domain is idealised and an f-plane is used for Coriolis force, so the domain can be rotated without loss of generality. Fields are: double THICKNESS(time, Y, X) - the ice thickness (floating and grounded) in meters double MELTRATE(time, Y, X) - the melt/freeze rate in meters ice per year (positive where melting) double HEIGHT_ABOVE_FLOAT(time, Y, X) - the portion of the ice column greater than the maximum floating thickness (calculated as double MASK(time, Y, X)) - a file indicating the parts of the domain that actually represent the computational domain (ignores walls, etc). Equal to 1 where there is ice sheet or shelf, 0 where there is open ocean, and -1 outside of the physical domain. One additional file is provided with dimensions X,Y only, detailing the bedrock elevation: BED.nc. |
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| Data Resolution: | |
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| Latitude Resolution | N/A |
| Longitude Resolution | N/A |
| Horizontal Resolution Range | 1 km - < 10 km or approximately .01 degree - < .09 degree |
| Vertical Resolution | 20 m |
| Vertical Resolution Range | N/A |
| Temporal Resolution | approx 200-600 years |
| Temporal Resolution Range | N/A |