C058-08
Precipitation modulates Greenland Ice Sheet size during the Holocene

Tuesday, 15 December 2020: 11:58
Virtual
Elizabeth K Thomas1, Joshua K Cuzzone2, Jason P Briner3, Jessica Badgeley4, Allison Cluett5, Jacob Downs6, Alia J Lesnek5, Nicolas E. Young7, Estelle Allan8, Ole Bennike9, Beata M Csatho3, Anne de Vernal10, Gregory J. Hakim11, Johnson Jesse12, Eric Y Larour13, Mathieu Morlighem14, Sophie Nowicki15, Joerg Schaefer7, Nicole Schlegel16, Eric J. Steig17 and Margie Turrin18, (1)University at Buffalo, Department of Geosciences, Buffalo, NY, United States, (2)Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, OR, United States, (3)University at Buffalo, Department of Geology, Buffalo, NY, United States, (4)University of Washington, Department of Earth and Space Sciences, Seattle, WA, United States, (5)University at Buffalo, Buffalo, NY, United States, (6)University of Montana, Missoula, MT, United States, (7)Columbia University of New York, Lamont-Doherty Earth Observatory, Palisades, NY, United States, (8)GEOTOP-UQAM, Montreal, QC, Canada, (9)GEUS, Copenhagen, Denmark, (10)Univ Quebec Montreal, Montréal, QC, Canada, (11)University of Washington, Department of Atmospheric Sciences, Seattle, WA, United States, (12)University of Montana, Missoula, United States, (13)Jet Propulsion Laboratory, Pasadena, CA, United States, (14)University of California - Irvine, Irvine, CA, United States, (15)NASA GSFC, Greenbelt, MD, United States, (16)NASA Jet Propulsion Laboratory, Pasadena, United States, (17)University of Washington, Earth and Space Sciences, Seattle, WA, United States, (18)LDEO of Columbia University, Palisades, NY, United States
Recorded Presentation
Abstract:
As the Arctic continues to warm this century, winter precipitation is projected to increase in response to sea ice retreat. If that precipitation falls as snow on the Greenland Ice Sheet (GrIS), the resulting increase in mass could offset some of the losses due to rising temperature, yet the magnitude of this effect is not well constrained. Here, we assess the relative importance of precipitation and temperature on the southwestern sector of the GrIS during the Holocene using glacial geologic and paleoclimate data and recently published ice sheet model simulations. This sector of the ice sheet is well positioned to address this question, as it borders the Labrador Sea and Baffin Bay, which experienced large changes in winter sea ice cover that caused large changes in winter precipitation. We force Holocene simulations of the Ice Sheet System Model with an ensemble of temperature and precipitation histories derived from a data assimilation product. The ensemble of simulations includes scenarios with high and low precipitation (max. difference of 120 mm/yr during early Holocene) and high and low temperature (max. difference of 3°C during early Holocene). This allows us to assess ice sheet changes under varying precipitation in the same temperature scenario, and under varying temperatures in the same precipitation scenario. We find that, compared to the low precipitation scenario, the high scenario halves the difference in ice sheet response in the high and low temperature scenarios. Though temperature appears to be the dominant factor, precipitation acts to strongly modulate the response of the southwestern sector of the Greenland Ice Sheet during the Holocene.
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