Recent publications/pre-prints by Lev Tarasov
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Sporadically updated publications list for Lev Tarasov
Matthew Drew and Lev Tarasov. North American Pleistocene Glacial
Erosion and Thin Pliocene Regolith Thickness Inferred from
Data-Constrained Fully Coupled Ice-Climate-Sediment Modelling,
submitted to Climates of the Past: preprint under
discussion and open review .
Kevin Hank and Lev Tarasov. The comparative role of physical
system processes in Hudson Strait ice stream cycling: a comprehensive
model-based test of Heinrich event hypotheses, submitted to Climates
of the Past: preprint under discussion and open
review .
A. Reyes AV, A. Carlson, J. Clark, L. Guillaume, G. Milne,
L. Tarasov, E. Clarlson, F. He, M. Caffee, K. Wilcken, and D. Rood.
Timing of Cordilleran-Laurentide ice-sheet separation: implications
for sea-level rise; Quaternary Science Reviews:
2024 .
Crow, B. R., L. Tarasov, M. Schulz and M. Prange. Uncertainties
originating from GCM downscaling and bias correction with application
to the MIS-11c Greenland Ice Sheet, Climates of the
Past: 2024 .
April Dalton, Martin Margold, Helen Dulfer, Sophie Norris, and
Lev Tarasov. Response of North American ice sheets to the Younger
Dryas cold reversal (12.9 to 11.7 ka). submitted to Earth Science
Reviews. Under review.
Soran Parang, Glenn A. Milne, Maryam Yousefi, Ryan Love, and Lev
Tarasov. Constraining Models of Glacial Isostatic Adjustment in
Eastern North America. Submitted to QSR. Under review.
Ryan Love, Glenn A. Milne, Parviz Ajourlou, Soran Parang, Lev
Tarasov, and Konstantin Latychev. A Fast Surrogate Model for 3D-Earth
Glacial Isostatic Adjustment using Tensorflow (v2.8.10) Artificial
Neural Networks, submitted to
GMD:
preprint under discussion and open review .
Love, R., L. Tarasov, H. Andres, A. Condron, X. Zhang, and
G. Lohmann. Exploring the climate system response to a range of
freshwater representations: Hosing, Regional, and Freshwater
Fingerprints, submitted to Climates of the
Past:
preprint under discussion and open review .
Kevin Hank, Lev Tarasov, and Elisa Mantell. Modeling
sensitivities of thermally and hydraulically driven ice stream surge
cycling, Geoscientific Model
Development:
2023 .
Matthew Drew and Lev Tarasov. Surging of a Hudson Strait Scale
Ice Stream: Subglacial hydrology matters but the process details
mostly do not, The Cryosphere:
2023 .
Benoit S. Lecavalier, Lev Tarasov, Greg Balco, Perry Spector,
Claus-Dieter Hillenbrand, Christo Buizert, Catherine Ritz, Marion
Leduc-Leballeur, Robert Mulvaney, Pippa L. Whitehouse, Michael
J. Bentley, and Jonathan Bamber. Antarctic ice sheet paleo-constraint
database, Earth System Science Data: 2023 .
Lev Tarasov and Michael Goldstein. Assessing uncertainty in past
ice and climate evolution : overview, stepping-stones, and
challenges, current version , 2022. This
version was rejected by a CP editor for being too
long. Original
2021 CPD submission and reviews. Our
detailed response to the reviewers. For clearly defined
audiences, we selective introduce Bayesian inference, show how it can
be effectively useless if uncertainties are not adequately addressed,
and suggest ways to move forward.
Frick, Maximilian and Cacace, Mauro and Klemann, Volker and Tarasov,
Lev and Scheck-Wenderoth, Magdalena. Hydrogeologic and Thermal
Effects of Glaciations on the Intracontinental Basins in Central
and Northern Europe, Frontiers in
Water online
article, 2022.
I. Malmierca-Vallet, L.C. Sime,..,Lev
Tarasov,... Dansgaard-Oeschger events in climate models: Review and
baseline MIS3 protocol, submitted to Climates of the
Past/EGUsphere:
preprint under discussion and open review .
W. Colgan, H. Henriksen, O. Bennike,.., L Tarasov, ... Sea-level
rise in Denmark: paleo context, recent projections and policy
implications, GEUS
Bulletin 49, online
article, 2022.
Yuchen Sun, Gregor Knorr, Xu Zhang, Lev Tarasov, Stephen Barker,
Martin Werner, and Gerrit Lohmann. Ice sheet decline and rising
atmospheric CO2 control AMOC sensitivity to deglacial meltwater
discharge, GPC 210, online
article, 2022.
Claude Hillaire-Marcel, Paul G. Myers, Shawn Marshall, Lev
Tarasov, Karl Purcell, Christelle Not, and Anne De Vernal. Challenging
the hypothesis of an Arctic Ocean lake during recent glacial episodes,
J. Quat. Sci. 37(4), online
article, 2022.
Jorie Clark, Anders E. Carlson, Alberto V. Reyes, .., Lev
Tarasov, ... The age of the opening of the Ice-Free Corridor and
implications for the peopling of the Americas, PNAS
119(14), online
article, 2022.
Reyes AV, Carlson AE, Milne GA, Tarasov L, Reimink JR, Caffee
MW. Revised chronology of northwest Laurentide ice-sheet
deglaciation from 10Be exposure ages on boulder erratics. Quaternary
Science Reviews
277:107369, online
article, 2022.
Sophie L. Norris, Lev Tarasov, Alistair J. Monteath, John
C. Gosse, Alan J. Hidy, Martin Margold, Duane G. Froese. Rapid retreat
of the southwestern Laurentide Ice Sheet during the Bølling-Allerød
interval, Geology
50(4), online article,
2022.
Ryan Love, Heather Andres, Alan Condron and Lev
Tarasov. Freshwater routing in eddy-permitting simulations of the last
deglacial: the impact of realistic freshwater discharge. CP,
online article, 2021.
Tamsin Edwards, Sophie Nowicki, and many others including Lev
Tarasov. land ice contributions to twenty-first-century sea level
rise, Nature 15, 593,
74+, online
article, 2021.
Kierulf, H. P., Steffen, H., Barletta, V. R., Lidberg, M.,
Johansson, J., Kristiansen, O., and Tarasov, L.: A GNSS velocity field
for geophysical applications in Fennoscandia, J. of Geodyn., 146,
online article, 2021.
Anthony Payne, Sophie Nowicki, and many others including Lev
Tarasov. Future Sea Level Change Under Coupled Model Intercomparison
Project Phase 5 and Phase 6 Scenarios From the Greenland and Antarctic
Ice Sheets, GRL, 48, online article,
2021.
Taimaz Bahadory, Lev Tarasov, and Heather Andres. Last glacial
inception trajectories for the Northern Hemisphere from coupled ice
and climate modelling. CP,
online article, 2021.
Laurie C. Menviel, Luke C. Skinner, Lev Tarasov, and Polychronis
C. Tzedakis. An ice–climate oscillatory framework for
Dansgaard–Oeschger cycles. Nature
Reviews, online
article, 2020.
H. Goelzer, S. Nowicki, ..., L. Tarasov, ... (over 40 authors in
total). The future sea-level contribution of the Greenland ice
sheet: a multi-model ensemble study of ISMIP6. The
Cryosphere,
online article, 2020.
April S. Dalton, Martin Margold, Chris R. Stokes, Lev Tarasov,
Arthur S. Dyke, and many others... An updated radiocarbon-based ice
margin chronology for the last deglaciation of the North American Ice
Sheet Complex. QSR,
online article, 2020.
Joseph Kuchar, Glenn Milne, Alexander Hill, Lev Tarasov, and
Maaria Nordman. An investigation into the sensitivity of postglacial
decay times to uncertainty in the adopted ice
history. Geoph. J. Int,
online article, 2020.
Holger Steffen, Rebekka Steffen, and Lev Tarasov.
Modelling of glacially-induced stress changes in Latvia, Lithuania and the Kaliningrad
District of Russia. BALTICA vol 32, no. 1,
online article, 2019.
J.L. Wadham, J.R. Hawkings, L. Tarasov, L.J. Gregoire,
R.G.M. Spencer, M. Gutjahr, A. Ridgwell, and K.E. Kohfeld. Ice sheets
matter for the global carbon cycle. Nat. Comm.,
open access online article, 2019.
Heather Andres and Lev Tarasov. Towards understanding
potential atmospheric contributions to abrupt climate changes:
Characterizing changes to the North Atlantic eddy-driven jet over the
last deglaciation, Clim. of the Past,
open access online article, 2019.
L. Menviel, E. Capron, A. Govin, A. Dutton, L. Tarasov, et al.
The penultimate deglaciation: protocol for PMIP4 transient
numerical simulations between 140 and 127 ka, Geosci. Model Devel.,
open access online article, 2019.
Olave Vestol, Jonas Agren, Holger Steffen, Halfdan Kierulf, and
Lev Tarasov. NKG2016LU: a new land uplift model for Fennoscandia and
the Baltic Region, Journal of Geodesy,
online article, 2019.
Taimaz Bahadory and Lev Tarasov. LCice 1.0: A generalized Ice
Sheet Systems Model coupler for LOVECLIM version 1.3: description,
sensitivities, and validation with the Glacial Systems Model.
Geosci. Model Dev.,
open access online
article, 2018.
Mark Kavanagh, and Lev Tarasov: BrAHMs V1.0: A fast,
physically-based subglacial hydrology model for continental-scale
application, Geosci. Model Dev.,
https://doi.org/10.5194/gmd-11-3497-2018 , 2018
Anders E. Carlson, Lev Tarasov , and Tamara Pico. Rapid
Laurentide ice-sheet advance towards southern last glacial maximum
limit during marine isotope stage 3. Quaternary Science Reviews 196,
https://doi.org/10.1016/j.quascirev.2018.07.039, 2018.
Maryam Yousefi, Glenn A. Milne, Ryan Love, and Lev Tarasov.
Glacial isostatic adjustment along the Pacific coast of central North
America 193, https://doi.org/10.1016/j.quascirev.2018.06.017, 2018.
Shepherd, A. and the IMBIE team; Mass balance of the Antarctic
Ice Sheet from 1992 to 2017, Nature, 558, pages 219-222, 2018.
Frederik Schenk, Minna Valiranta, Francesco Muschitiello, Lev
Tarasov, Maija Heikkila, Svante Bjorck, Jenny Brandefelt, Arne
V. Johansson, Jens-Ove Naslund, and Barbara Wohlfarth; Warm summers
during the Younger Dryas cold reversal, Nature Communications, 9(1),
2041-1723, doi:10.1038/s41467-018-04071-5,
https://doi.org/10.1038/s41467-018-04071-5, 2018.
Paul J. Morris, Graeme T.Swindels, Paul J. Valdes, Ruza Ivanovic, Lauren Gregoire, Mark Smith, Lev
Tarasov, Alan Haywood, and Karen Bacon. Peat initiation triggered by regionally-asynchronous
warming. Proc. Nat. Ac. of Sci., 2018. https://doi-org.qe2a-proxy.mun.ca/10.1073/pnas.1717838115
Kageyama, M. and Braconnot, P. and Harrison, S. P. and Haywood,
A. M. and Jungclaus, J. and Otto- Bliesner, B. L. and Peterschmitt,
J.-Y. and Abe-Ouchi, A. and Albani, S. and Bartlein, P. J. and
Brierley, C. and Crucifix, M. and Dolan, A. and Fernandez-Donado,
L. and Fischer, H. and Hopcroft, P. O. and Ivanovic, R. F. and
Lambert, F. and Lunt, D. J. and Mahowald, N. M. and Peltier, W. R. and
Phipps, S. J. and Roche, D. M. and Schmidt, G. A. and Tarasov, L. and
Valdes, P. J. and Zhang, Q. and Zhou, T.; The PMIP4 contribution
to CMIP6 - Part 1: Overview and over-arching analysis
plan. Geoscientific Model Development. 1033-1057, 2018. https://www.geosci-model-dev.net/11/1033/2018/
Joseph Kuchar, Glenn Milne, Martin Wolstencroft, Ryan Love, Lev
Tarasov, Marc Hijma. The Influence of Sediment Isostatic Adjustment on
Sea-Level Change and Land Motion along the US Gulf Coast. Journal of
Geophysical Research: Solid Earth, DOI: 10.1002/2017JB014695, 2018
Mohammad Hizbul Bahar Arif, Lev Tarasoff, and Tristan Hauser. The
Climate Generator: Stochastic climate representation for glacial cycle
integration, Geosci. Model Dev. Discuss.,
https://www.geosci-model-dev-discuss.net/gmd-2017-276/, 2017
Kageyama, M., Albani, S., Braconnot, P., Harrison, S. P., Hopcroft,
P. O., Ivanovic, R. F., Lambert, F., Marti, O., Peltier, W. R.,
Peterschmitt, J.-Y., Roche, D. M., Tarasov, L., Zhang, X., Brady,
E. C., Haywood, A. M., LeGrande, A. N., Lunt, D. J., Mahowald, N. M.,
Mikolajewicz, U., Nisancioglu, K. H., Otto-Bliesner, B. L., Renssen,
H., Tomas, R. A., Zhang, Q., Abe-Ouchi, A., Bartlein, P. J., Cao, J.,
Li, Q., Lohmann, G., Ohgaito, R., Shi, X., Volodin, E., Yoshida, K.,
Zhang, X., and Zheng, W.: The PMIP4 contribution to CMIP6 – Part 4:
Scientific objectives and experimental design of the PMIP4-CMIP6 Last
Glacial Maximum experiments and PMIP4 sensitivity experiments,
Geosci. Model Dev., 10, 4035-4055,
https://doi.org/10.5194/gmd-10-4035-2017, 2017
Benoit S. Lecavalier, David A. Fisher, Glenn A. Milne, Bo
M. Vinther, Lev Tarasov, Philippe Huybrechts, Denis Lacelle, Brittany
Main, James Zheng, Jocelyne Bourgeois, and Arthur S. Dyke. High Arctic
Holocene temperature record from the Agassiz ice cap and Greenland ice
sheet evolution, PNAS, 114(23), doi:10.1073/pnas.1616287114,
2017.
Kageyama, M. and Braconnot, P. and Harrison, S. P. and Haywood,
A. M. and Jungclaus, J. and Otto- Bliesner, B. L. and Peterschmitt,
J.-Y. and Abe-Ouchi, A. and Albani, S. and Bartlein, P. J. and
Brierley, C. and Crucifix, M. and Dolan, A. and Fernandez-Donado,
L. and Fischer, H. and Hopcroft, P. O. and Ivanovic, R. F. and
Lambert, F. and Lunt, D. J. and Mahowald, N. M. and Peltier, W. R. and
Phipps, S. J. and Roche, D. M. and Schmidt, G. A. and Tarasov, L. and
Valdes, P. J. and Zhang, Q. and Zhou, T.(2017). PMIP4- CMIP6: the
contribution of the Paleoclimate Modelling Intercomparison Project to
CMIP6. Geoscientific Model Development Discussions. 2016: 1-46.
Hugo Beltrami, Gurpreet S. Matharoo, Jason E. Smerdon, Lizett Illanes,
and Lev Tarasov. Impacts of the Last Glacial Cycle on ground surface
temperature reconstructions over the last millennium,
Geophys. Res. Lett., 43, doi:10.1002/2016GL071317, 2016.
Ryan Love, Glenn A.Milne, Lev Tarasov, Simon E. Engelhart, Marc P. Hijma,
Konstantin Latychev, Benjamin P. Horton, and Torbjorn E. Tornqvis.
The contribution of glacial isostatic adjustment
to projections of sea-level change along the Atlantic
and Gulf coasts of North America, Earth's Future,4, 440-464,
doi:10.1002/2016EF000363, 2016.
online article.
Ruza F. Ivanovic, Lauren J. Gregoire, Masa Kageyama, Didier
M. Roche, Paul J. Valdes, Andrea Burke, Rosemarie Drummond, W. Richard
Peltier, and Lev Tarasov. Transient climate simulations of the
deglaciation 21-9 thousand years before present; PMIP4 Core experiment
design and boundary conditions, Geosci. Model Dev., 9, 2563-2587,
doi:10.5194/gmd-9-2563-2016, 2016.
Dusterhus, A.; Rovere, A.; Carlson, A. E.; Horton, B. P.; Klemann, V.;
Tarasov, L.; Barlow, N. L. M.; Bradwell, T.; Clark, J.; Dutton, A.;
Gehrels, W. R.; Hibbert, F. D.; Hijma, M. P.; Khan, N.; Kopp, R. E.;
Sivan, D.; Tornqvist, T. E.: Palaeo-sea-level and palaeo-ice-sheet
databases: problems, strategies, and perspectives, Climate of the
Past, 12, 911-921, doi:10.5194/cp-12-911-2016.
Chris Stokes, Martin Margold, Chris D. Clark, and Lev Tarasov.
Ice stream activity scaled to ice sheet volume during
Laurentide Ice Sheet deglaciation. Nature, vol 530, doi:10.1038/nature16947, 2016.
Abe-Ouchi, A., Saito, F., Kageyama, M., Braconnot, P., Harrison,
S. P., Lambeck, K., Otto-Bliesner, B. L., Peltier, W. R., Tarasov, L.,
Peterschmitt, J.-Y., and Takahashi, K.: Ice-sheet configuration in the
CMIP5/PMIP3 Last Glacial Maximum experiments, Geosci. Model
Dev., 8, 3621-3637, 2015.
online article.
Jerome Goslin, Brigitte Van Vliet Lanoe, Giorgio Spada, Sarah
Bradley, Lev Tarasov, Simon Neill, Serge Suanez. A new Holocene
relative sea-level curve for western Brittany (France): Insights on
isostatic dynamics along the Atlantic coasts of north-western
Europe. Quaternary Science Reviews 129, 341-365,doi.org/10.1016/j.quascirev.2015.10.029, 2015.
K. Le Morzadec, L. Tarasov, M. Morlighem, and H. Seroussi. A new
sub-grid surface mass balance and flux model for continental-scale ice
sheet modelling: validation and last glacial cycle, GMD, 8, 3199-3213,
doi:10.5194/gmd-8-3199-2015, 2015.
Chris R Stokes; Lev Tarasov; Robin Blomdin; Thomas M Cronin;
Timothy G Fisher; Richard Gyllencreutz; Clas Hättestrand; Jakob
Heyman; Richard Hindmarsh; Anna Hughes; Martin Jakobsson; Nina
Kirchner; Stephen J Livingstone; Martin Margold; Julian Murton; Riko
Noormets; Richard W Peltier; Dorothy M Peteet; David Piper; Frank
Preusser; Hans Renssen; Dave H Roberts; Didier Roche; Francky
Saint-Ange; Arjen P Stroeven; James T Teller. On the Reconstruction of
Palaeo-Ice Sheets: Recent Advances and Future Challenges. Quaternary
Science Reviews, vol 125, p 15-49, doi:10.1016/j.quascirev.2015.07.016, 2015.
Stephen Livingstone; Robert D Storrar; John K Hillier; Chris R
Stokes; Chris D Clark; Lev Tarasov. An ice-sheet scale comparison of
eskers with modelled subglacial drainage routes, Geomorphology,
pp. 104-112, 10.1016/j.geomorph.2015.06.016, 2015.
Bart Root, Lev Tarasov, and Wouter van der Wal. GRACE gravity
observations constrain Weichselian ice thickness in the Barents Sea,
GRL, DOI: 10.1002/2015GL063769, 2015.
Maaria Nordman, Glenn Milne, Lev Tarasov. Reappraisal of the
Angerman River decay time estimate and its application to determine
uncertainty in Earth viscosity structure, Geophysical J. Int., 201, 811–822, doi: 10.1093/gji/ggv051, 2015.
Peter U. Clark and Lev Tarasov. Closing the sea level budget at the Last Glacial Maximum.
PNAS Commentary, 111(45), 15861-15862; doi:10.1073/pnas.1418970111, 2014.
Robert Briggs, David Pollard, and Lev Tarasov. A data constrained
large ensemble analysis of Antarctic evolution since the Eemian,
Quaternary Science Reviews, 103, 91-115, 2014.
Benoit S. Lecavalier, Glenn A. Milne, Matthew J.R. Simpson,
Leanne Wake, Philippe Huybrechts, Lev Tarasov, Kristian K. Kjeldsen,
Svend Funder, Antony J. Long, Sarah Woodroffe, Arthur S. Dyke Nicolaj
K. Larsen. A model of Greenland ice sheet deglaciation constrained by
observations of relative sea level and ice extent, Quaternary Science
Reviews, 102, 54-84, 2014.
H. Beltrami G. S. Matharoo, L. Tarasov, V. Rath and
J. E. Smerdon. Numerical studies on the Impact of the Last Glacial
Cycle on recent borehole temperature profiles: implications for
terrestrial energy balance, Climate of the Past, 10, 1693–1706, 2014.
doi:10.5194/cp-10-1693-2014
Robert Briggs, David Pollard, and Lev Tarasov. A glacial systems model configured for large ensemble analysis of
Antarctic deglaciation, The Cryosphere, 2013.
Stephen Livingstone, Chris D. Clark, and Lev Tarasov; Modelling North
American palaeo-subglacial lakes and their meltwater drainage
pathways, Earth and Plan. Sci. Let., 2013. http://dx.doi.org/10.1016/j.epsl.2013.04.017
Alexandre Melanson, Trevor Bell, and Lev Tarasov;
Numerical Modelling of Subglacial Erosion and Sediment Transport and its Application to the North
American Ice Sheets over the Last Glacial Cycle,
Quaternary Science Reviews, 2013.
http://dx.doi.org/10.1016/j.quascirev.2013.02.017
Robert Briggs and Lev Tarasov. Evaluating model-derived deglaciation
chronologies for Antarctica. Quaternary Science Reviews, 2013.
http://dx.doi.org/10.1016/j.quascirev.2012.11.021
Chris Stokes, Lev Tarasov, and A.S. Dyke; Dynamics of the North
American Ice Sheet Complex during its inception and build-up to the
Last Glacial Maximum, Quaternary Science Reviews, 2012.
Lev Tarasov; Arthur S. Dyke, Radford M. Neal, and W.R. Peltier;
A data-calibrated distribution of deglacial chronologies for
the North American ice complex from glaciological modelling, Earth
and Plan. Sci. Let., 2012.
revised submission,primary supplement,RSL plots,Tertiary supplement,online article.
Tristan Hauser, Andrew Keats, and Lev Tarasov; Artificial
neural network assisted Bayesian calibration of climate models,
Clim. Dyn., 2011.supplement,online article.
R. Calov, R. Greve, A. Abe-Ouchi, E. Bueler, P. Huybrechts,
J. Johnson, F. Pattyn, D. Pollard, C. Ritz, F. Saito, and
L. Tarasov, Results from the Ice-Sheet Model Intercomparison
Project-Heinrich Event INtercOmparison (ISMIP HEINO), J. of
Glaciology, 56, 371-383, 2010.
K. Westley; T. Bell; M. Renouf; and L. Tarasov, Impact assessment of current and future sea-level change
on coastal archaeological resources illustrated examples from northern Newfoundland, J. of Island and
Coastal Archaeology, 2010.
R. L. Stotler, S. K. Frape, L. Ahonen; I. D. Clark, S. Greene, M. Hobbs, E. Johnson; J.-M. Lemieux, W. R.
Peltier, L. Pratt, T. Ruskeeniemi, E. A Sudicky, and L. Tarasov, Thermogenic Methane Hydrate in a Crystalline
Shield, Earth and Plan. Sci. Let. , 296, 384-394, doi:10.1016/j.epsl.2010.05.024, 2010.
Chris Stokes and Lev Tarasov, Ice streaming in the Laurentide Ice Sheet: A first comparison between data-
calibrated numerical model output and geological evidence, Geophys. Res. Let., doi:10.1029/2009GL040990,
2010.
J.-M. Lemieux, E. A. Sudicky, W.R. Peltier, L. Tarasov, Simulating the impact of glaciations on
continental groundwater flow systems. I. Relevant processes and model formulation, J. Geophys. Res.,
doi:2007JF000928, 2008.
J.-M. Lemieux, E. A. Sudicky, W.R. Peltier, L. Tarasov, Simulating the impact of glaciations on
continental groundwater flow systems. II. Model application to the Wisconsinian glaciation over the
Canadian landscape, J. Geophys. Res., doi:2007JF000929, 2008.
J.-M. Lemieux, E. A. Sudicky, W.R. Peltier,
L. Tarasov, Dynamics of groundwater recharge and seepage over the
Canadian landscape during the Wisconsinian glaciation,
J. Geophys. Res, 113, F01011, doi:10.1029/2007JF000838, 2008.
abstract
Pleistocene glaciations and their associated dramatic climatic conditions are suspected
to have had a large impact on the groundwater flow system over the entire North American
continent. Because of the myriad of complex flow-related processes involved during a
glaciation period, numerical models have become powerful tools for examining
groundwater flow system evolution in this context. In this study, a series of key processes
pertaining to coupled groundwater flow and glaciation modeling, such as density-
dependent (i.e., brine) flow, hydromechanical loading, subglacial infiltration, isostasy, and
permafrost development, are included in the numerical model HydroGeoSphere to
simulate groundwater flow over the Canadian landscape during the Wisconsinian
glaciation (@120 ka to present). The primary objective is to demonstrate the immense
impact of glacial advances and retreats during the Wisconsinian glaciation on the
dynamical evolution of groundwater flow systems over the Canadian landscape, including
surface-subsurface water exchanges (i.e., recharge and discharge fluxes) in both the
subglacial and the periglacial environments. It is shown that much of the infiltration of
subglacial meltwater occurs during ice sheet progression and that during ice sheet
regression, groundwater mainly exfiltrates on the surface, in both the subglacial and
periglacial environments. The average infiltration/exfiltration fluxes range between 0 and
12 mm/a. Using mixed, ice sheet thickness dependent boundary conditions for the
subglacial environment, it was estimated that 15 to 70% of the meltwater infiltrated into the
subsurface as recharge, with an average of 43%. Considering the volume of meltwater that
was generated subsequent to the last glacial maximum, these recharge rates, which are
related to the bedrock type and elastic properties, are historically significant and therefore
played an immense role in the evolution of groundwater flow system evolution over the
Canadian landmass over the last 120 ka. Finally, it is shown that the permafrost extent
plays a key role in the distribution of surface-subsurface interaction because the presence
of permafrost acts as a barrier for groundwater flow.
L. Tarasov, Meltwater discharge and its dynamical role during the
Younger Dryas. Current Research in the Pleistocene. 24, 18-23,
2007.
first paragraph
The original suggestion, by Rooth (1982) and refined by Broecker and
al (1989), that the Younger Dryas was due to a reduction or shutdown
in the large ocean heat conveyor (thermohaline circulation) triggered
by a meltwater flood from eastward diversion of pro-glacial Lake
Agassiz outflow, has been widely accepted for over a decade. This
hypothesis fit inferred timing for a major reduction of southern
outflow via the Mississippi river, as recorded in various
paleoceanographic proxies from marine sedimentary cores from the Gulf
of Mexico. Furthermore, paleoceanographic evidence for a reduction in
the rate of the deep overturning circulation during the YD has become
quite robust. However, over the last few years, a number of
challenges have arisen. To assess our current understanding, I will
address three key issues in turn.
L. Tarasov and W. R. Peltier, The co-evolution of continental ice cover and permafrost extent
over the last glacial-interglacial cycle in North
America. J. Geophys. Res. vol. 112, F02S08,
doi:10.1029/2006JF000661, 2007.
pdf
abstract
The bed-thermal characteristics of a glacial systems model that has been calibrated
against a large set of relative sea-level, geodetic, and strandline observations are
examined for the previously glaciated sector of the North American continent.
The model compares favourably against the present day extent of
permafrost and against the observed temperature profiles from three deep boreholes when appropriate
bed-thermal conductivities are employed. Estimates
for the present day depth field of the lower permafrost boundary are
presented. We find a significant disequilibrium in the lower permafrost
boundary for most of the Arctic region, with present-day depth as much as 250 m
shallower than the equilibrium value for present day climate
forcing. This is largely due to the on-going response to the loss of
ice cover from the glacial period.
The time evolution of the sub-glacial warm-based area fraction is also
presented together with calibration derived confidence intervals. A peak
warm-based fraction of $50\% \pm 6\%$ is obtained at last glacial maximum
(LGM). The timing of the three largest ice volume maxima that were produced in response to
the obliquity component of orbital forcing during the last glacial
cycle matches that of the maxima for the warm-based area
fraction with no significant phase delay. Warm-based conditions are
required to enable ice streaming (fast flow) in the model. It is
therefore hypothesized that the expansion of the area covered by warm-based ice played a
critical role in producing a highly dynamic ice-sheet during both the
most intense growth and recession phases.
L. Tarasov and W. R. Peltier, A calibrated deglacial drainage chronology for the North American continent: Evidence of
an Arctic trigger for the Younger Dryas, Quat. Sci. Rev. vol 25, 659-688, 2006;
pdf
abstract
We present a new deglacial meltwater drainage chronology for the North
American ice sheet complex using a 3D glacial systems model calibrated
against a large set of paleo-proxies. Results indicate that North
America was responsible for a significant fraction of mwp1-a, with
order 1.5 dSv or larger (100 year mean) peak discharges into both the
Gulf of Mexico and the Eastern Atlantic and less than 1 dSv into the
Arctic Ocean.
Our most significant result concerns discharge into the Arctic
Ocean. The largest total discharge into the Arctic Ocean (ensemble
mean values of 1.0 to 2.2 dSv) occurs during the onset of the Younger
Dryas. The large majority of this discharge is locally sourced with
reduction of the Keewatin ice dome being the largest
contributor. Given that the only outlet from the Arctic Basin at this
time was via Fram Strait into the Greenland-Iceland-Norwegian Seas,
we hypothesize that this pulse was the trigger for the re-organization
of thermohaline circulation that is thought to have been responsible
for the Younger Dryas cold interval. In contradistinction with past
inferences and subject to the imperfectly constrained ice-margin
chronology, we also find that the Northwest outlet likely dominated
much of the post -13 kyr drainage of Lake Agassiz.
L. Tarasov and W. R. Peltier, Arctic freshwater forcing of the Younger Dryas cold reversal, Nature, vol 435, 662-665, 2005;
Nature link;
supplement (freely available)
abstract
The last deglaciation was abruptly interrupted by a millennial-scale
reversion to glacial conditions. The cause of this
Younger Dryas cold interval has been connected to a decrease in the
rate of North Atlantic Deep Water formation and to a resultant
weakening of the meridional overturning
circulation due to surface
freshening. In contrast, the earlier meltwater pulse 1-a
event, of disputed provenance, produced
no apparent reduction of the meridional overturning
circulation. To identify the source of the
freshwater forcing that weakened the meridional overturning
circulation, we present the analysis of objectively-constrained
drainage chronology ensembles for the North American ice-sheet derived
from a calibrated Glacial Systems Model. We find that this
ice-sheet sourced about half of meltwater pulse 1-a. During the onset of the
Younger Dryas, we find that the largest combined meltwater/iceberg
discharge was directed into the Arctic Ocean. Given that the only
drainage outlet from the Arctic Ocean was via Fram Strait into the
Greenland-Iceland-Norwegian Seas, where North
Atlantic Deep Water is formed today, we
hypothesize that it was this Arctic freshwater flux that triggered
the Younger Dryas cold reversal.
L. Tarasov and W. R. Peltier, A geophysically constrained large ensemble analysis of the deglacial history of the North American ice sheet complex, Quat. Sci. Rev. vol 23, 359-388, 2004;
pdf
abstract
Past reconstructions of the deglaciation history of the North American
(NA) ice sheet complex have relied either on largely unconstrained and
limited explorations of the phase space of solutions produced by
glaciological models or upon geophysical inversions of relative sea
level (RSL) data which suffer from incomplete geographic coverage of
the glaciated regions, load history amplitude/timing ambiguities, and
a lack of a priori glaciological self-consistency. As a first step in
the development of a much more highly constrained deglaciation
history, we present a synthesis of these two previously disjoint
methodologies based on a large ensemble of glacial cycle simulations
using a three dimensional thermo-mechanically coupled ice sheet
model. Twenty glacial system model parameters, chosen so as to best
cover the true deglacial phase space, were varied across the
ensemble. Furthermore, a new high-resolution digitized ice margin
chronology was imposed on the model in order to significantly limit
the uncertainties associated with deglacial climate forcing. The model
is simultaneously constrained by a large set of high quality RSL
histories, a space geodetic observation of the present day rate of
vertical motion of the crust from Yellowknife and a traverse of
absolute gravity measurements from the west coast of Hudson Bay
southward into Iowa.
The general form of the Last Glacial Maximum (LGM) ice topography that
ensues when model results are subject to geophysical constraints is an
ice sheet dominated by a large (3.3 to 4.3 km maximum ice thickness)
Keewatin dome to the west of Hudson Bay connected to a major ice ridge
running southeast to the Great Lakes, together with a Hudson Bay
region that has relatively thin ice and an Arctic region heavily
incised by open-water and/or ice-shelves. Geographically restricted
fast flows due to sub-glacial till-deformation are shown to be
critical to obtaining such a multi-domed late glacial Laurentide Ice
Sheet structure, one that has been previously inferred on the basis of
geomorphological data and that is required to fit the geophysical
constraints. Our results further suggest that the NA contribution to
LGM eustatic sea level drop is likely to be in the range of 60 to 75
m.
L. Tarasov and W. R. Peltier, Greenland glacial history, borehole constraints and Eemian extent, J. Geophys. Res. vol. 108(B3), 2124-2143, 2003;
pdf
abstract
We examine the extent to which observations from the Greenland ice
sheet combined with 3D dynamical ice sheet models and Semi-Lagrangian
tracer methods can be used to constrain inferences of the Eemian
evolution of the ice sheet, of the extent and frequency of summit
migration during the 100 kyr ice age cycle, and of the deep geothermal
flux of heat from the earth into the base of the ice sheet. Relative
sea-level, present-day surface geometry, basal temperature, and age
and temperature profiles from GRIP are imposed as constraints to tune
ice sheet model and climate forcing parameters. Despite the paucity of
observations, model-based inferences suggest a significant north-east
gradient in geothermal heat flux. Our analyses also suggest that
during the glacial cycle, the contemporaneous summit only occupied the
present-day location during interglacial periods. Based on the
development and use of a high resolution Semi-Lagrangian tracer
analysis methodology for del 18 O we rule out isotropic flow
disturbances due to summit migration as a possible source of the high
Eemian variability of the GRIP del 18 O record. Finally, in contrast
with results obtained in some recent attempts to infer the extent to
which Greenland may have contributed to the anomalous high stand of
Eemian sea-level, we find that conservative bounds for this
contribution are 2 to 5.2 m, with a more likely range of 2.7 to 4.5
m.
L. Tarasov and W. R. Peltier, Greenland glacial history and local geodynamic consequences,
Geophy. J. Int., vol 150, 198-229, 2002;
pdf
abstract
Space-time reconstructions of the continental ice-sheets that existed
at Last Glacial Maximum(LGM) have previously been produced using two
entirely independent methodologies, respectively that based upon the
use of theoretical models of ice-sheet accumulation and flow and that
based upon the geophysical inversion of relative sea level (RSL)
histories from previously ice-covered regions. The analyses described
in this paper demonstrate the significant advantages that derive from
the simultaneous application of both methods to the particular case of
Greenland. We thereby show that the ICE-4G reconstruction of the
glaciation history of this region from LGM to present, which was based
upon the geophysical inversion of RSL data alone, was reasonably
accurate in the peripheral regions where RSL data were available but
inaccurate in the interior of the ice-sheet which was
unconstrained by such information. We test the new model of Greenland
glacial history determined by the simultaneous application of the
constraints that derive from ice-sheet modelling and the geophysical
inversion of RSL data by employing recently published geodetic
inferences of mass-balance over the entire interior region of the ice
sheet and of GPS measurements of vertical crustal motion. These
observations, which were not employed to constrain the ice-sheet
reconstruction, provide significant support for the new glacial history for
Greenland that our analyses have led us to infer.
L. Tarasov and W.R. Peltier, Laurentide ice sheet form in Glen flow
law based models, Ann. Glac., vol. 30, 177-186, 2000.
W.R. Peltier, D.L. Goldsby, D.L. Kohlstedt, and L. Tarasov,
Ice-age ice sheet rheology: constraints from Last Glacial Maximum form
of the Laurentide ice sheet, Ann. Glac. , vol. 30, 163-176, 2000.
S.J. Marshall, L. Tarasov, G.K.C. Clarke and W.R.
Peltier, Glaciology of Ice Age cycles: Physical processes and
modelling challenges, Can. J. Earth Sci., vol. 37, 769-793, 2000.
Payne, A. J. and 10 others,
Results from the EISMINT model
intercomparison: the effects of thermomechanical coupling,
J. Glac., vol. 46, 227-238, 2000.
L. Tarasov and W.R. Peltier, The Impact of Thermo-mechanical
Ice sheet Coupling on a Model of the 100 kyr Ice-Age Cycle,
J. Geophys. Res., vol. 104, 9517-9545, 1999.
W.T. Hyde, T.J. Crowley, L. Tarasov and W.R. Peltier, The
Pangean Ice Age: Studies with a coupled Climate-Ice Sheet Model,
Clim. Dyn., vol. 12, 100-115, 1999.
L. Tarasov and W.R. Peltier, A high-resolution model of the 100kyr Ice Age cycle;
Ann. Glac., vol. 25, 58-65, 1997.
L. Tarasov and W.R. Peltier, Terminating the 100 kyr Ice Age cycle,
J. Geophys. Res., vol. 102, 21665-21693, 1997.
Mann, R.B., L. Tarasov, and A. Zelnikov, Brick walls for black holes,
Class. Quant. Grav., vol. 9, 1487-1494, 1992.
Mann, R.B., A. Shiekh, and L. Tarasov, Classical and quantum
properties of two-dimensional black holes,
Nucl. Phys., vol. B341, 134-154, 1990.
Mann, R.B., L. Tarasov, D.G.C McKeon, and T. Steele, Operator
regularization and quantum gravity,
Nucl. Phys., vol. B311, 630-672, 1988.
L. Tarasov and R.B. Mann, Shifts of Integration Variable in the
Light-Cone Gauge,
Modern Phys. Let., vol. A1, 525-533, 1986.
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