Abstract:
This dataset presents the input and output data from a set of sensitivity experiments to simulate the evolution of the Laurentide ice sheet in the Early Holocene (10-7 thousand years ago). These data are presented in the manuscript "Simulating the Early Holocene demise of the Laurentide Ice Sheet with BISICLES (public trunk revision 3298)". Simulating the demise of the Laurentide Ice Sheet covering the Hudson Bay in the early Holocene is important for understanding the role of accelerated changes in ice sheet topography and melt in the '8.2 ka event', a century long cooling of the Northern Hemisphere by several degrees. Freshwater released from the ice sheet through a surface mass balance instability (known as the saddle collapse) has been suggested as a major forcing for the 8.2 ka event, but the temporal evolution of this pulse has not been constrained. Dynamical ice loss and marine interactions could have significantly accelerated the ice sheet demise, but simulating such processes requires computationally expensive models that are difficult to configure and are often impractical for simulating past ice sheets. Here, we developed an ice sheet model setup for studying the Laurentide Ice Sheet's Hudson Bay saddle collapse and the associated meltwater pulse in unprecedented detail using the BISICLES ice sheet model, an efficient marine ice sheet model of the latest generation, capable of refinement to kilometre-scale resolution and higher-order ice flow physics. The setup draws on previous efforts to model the deglaciation of the North American Ice Sheet for initialising the ice sheet temperature, recent ice sheet reconstructions for developing the topography of the region and ice sheet, and output from a general circulation model for a representation of the climatic forcing. The modelled deglaciation is in agreement with the reconstructed extent of the ice sheet and the associated meltwater pulse has realistic timing. Furthermore, the peak magnitude of the modelled meltwater equivalent (0.07-0.13 Sv) is compatible with geological estimates of freshwater discharge through the Hudson Strait. The results demonstrate that while improved representation of the glacial dynamics and marine interactions are key for correctly simulating the pattern of early Holocene ice sheet retreat, surface mass balance introduces by far the most uncertainty. The new model configuration presented here provides future opportunities to quantify the range of plausible amplitudes and durations of a Hudson Bay ice saddle collapse meltwater pulse and its role in forcing the 8.2 ka event.
Ilkka Matero was funded by the Leeds-York Natural Environment Research Council (NERC) Spheres Doctoral Training Partnership (NE/L002574/1). The contribution from Ruza Ivanovic was partly supported by NERC grant NE/K008536/1. Lauren Gregoire is funded by a UKRI Future Leaders Fellowship (MR/S016961/1). The work made use of the N8 HPC facilities, which are provided and funded by the N8 consortium and EPSRC (EP/K000225/1) and co-ordinated by the Universities of Leeds and Manchester.
Keywords:
8.2 ka event, BISICLES, Holocene, Laurentide, ice sheet, ice sheet model
Matero, I., Gregoire, L., & Ivanovic, R. (2019). Simulations of the Early Holocene demise of the Laurentide Ice Sheet with BISICLES (public trunk r3298) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/7e0b2d81-ee71-48d6-a901-3b417d482072
| Access Constraints: | No restrictions apply. |
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| Use Constraints: | This data is governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ |
| Creation Date: | 2019-11-01 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | UK PDC |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Ilkka S O Matero |
| Role(s) | Investigator |
| Organisation | University of Leeds |
| Name | Lauren J Gregoire |
| Role(s) | Technical Contact, Investigator |
| Organisation | University of Leeds |
| Name | Ruza F Ivanovic |
| Role(s) | Investigator |
| Organisation | University of Leeds |
| Parent Dataset: | N/A |
| Reference: | Matero I. S.O., Gregoire L. J. and Ivanovic R. F., submitted. Simulating the Early Holocene demise of the Laurentide Ice Sheet with BISICLES (public trunk r3298). GMD discussions. | |
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| Quality: | NetCDF files were produced by concatenating and filtering the raw output. This processing has not affected the accuracy of the data. | |
| Lineage: | The data is from a set of 11 simulations run with the BISICLES ice sheet model, setup to simulate the Laurentide ice sheet during the early Holocene period (10-7 ka). | |
| Paleo Temporal Coverage: | |
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| Paleo Start Date | 10 ka |
| Paleo End Date | 7.5 ka |
| Chronostratigraphic Unit | HOLOCENE |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | 40 |
| Northernmost | 75 |
| Longitude | |
| Westernmost | -100 |
| Easternmost | -53 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Data Resolution: | |
| Latitude Resolution | N/A |
| Longitude Resolution | N/A |
| Horizontal Resolution Range | 1 km - < 10 km or approximately .01 degree - < .09 degree |
| Vertical Resolution | N/A |
| Vertical Resolution Range | N/A |
| Temporal Resolution | 50 a |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | North America |
| Detailed Location | Eastern Canada |
| Source(s): |
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| Data Collection: | The data was produced through a series of experiments using the BISICLES ice sheet model. |
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 3.2 GB |
| Distribution Format | netCDF |
| Fees | N/A |
| Data Storage: | The dataset contains input and output files from a set of 11 simulations. This includes one control simulation with "standard" parameter values, and 10 sensitivity experiments where parameter values are perturbed to low and high values according to the following table of experiments. SIMULATION : PARAMETER MODIFIED : VALUE AMR_0 : Refinement resolution : 10 km AMR_2 : Refinement resolution : 2.5 km btrc_4x : Basal traction coefficient : 4 x 'control' btrc_6x : Basal traction coefficient : 6 x 'control' low_PDD : PDD (melt) factors snow & ice : 3 & 8 mm d-1 K-1 high_PDD : PDD (melt) factors snow & ice : 6 & 16 mm d-1 K-1 low_ss : Sub-shelf melt rate : 2 m a-1 high_ss : Sub-shelf melt rate : 45 m a-1 precip_half : Precipitation : 0.5 * 'standard' precip_075 : Precipitation : 0.75* 'standard' For each simulation, we provide one netcdf output file for each level of refinement, where "xxx_level0.nc" is at 10 km resolution, "xxx_level1.nc" is the first level of refinement (5 km resolution) and "xxx_level2.nc" is the data on the second level of refinement (2.5 km) (only available for the AMR_2 simulation). The netcdf output files contain the following variables: - Z_surface (time, y, x) : Surface elevation (m) - dThickness_dt (time, y, x) : Rate of thickness change (m/a) - thickness (time, y, x) : Ice thickness (m) - calvingFlux (time, y, x) : Calving flux (kg m-2 a-1) - xbVel (time, y, x) : Basal velocity on x axis (m/a) - xfVel (time, y, x) : Surface velocity on x axis (m/a) - ybVel (time, y, x) : Basal velocity on y axis (m/a) - yfVel (time, y, x) : Surface velocity on y axis (m/a) The dataset also contains input configuration files (intput/config), climate forcing (NetCDF files) and initial conditions input fields in NetCDF and HDF-5 formats. Details of these are provided in README.md The model output files contain data at 50 years interval through the duration of the simulations. |