In:
Climate of the Past, Copernicus GmbH, Vol. 14, No. 10 ( 2018-10-18), p. 1441-1462
Abstract:
Abstract. Over the past 0.8 million years, 100 kyr ice ages have dominated
Earth's climate with geological evidence suggesting the last glacial
inception began in the mountains of Baffin Island. Currently,
state-of-the-art global climate models (GCMs) have difficulty simulating
glacial inception, possibly due in part to their coarse horizontal resolution
and the neglect of ice flow dynamics in some models. We attempt to address
the role of regional feedbacks in the initial inception problem on Baffin
Island by asynchronously coupling the Weather Research and Forecast (WRF) model,
configured as a high-resolution inner domain over Baffin and an outer
domain incorporating much of North America, to an ice flow model using the
shallow ice approximation. The mass balance is calculated from WRF
simulations and used to drive the ice model, which updates the ice extent
and elevation, that then serve as inputs to the next WRF run. We drive the
regional WRF configuration using atmospheric boundary conditions from 1986
that correspond to a relatively cold summer, and with 115 kya insolation.
Initially, ice accumulates on mountain glaciers, driving downslope ice flow
which expands the size of the ice caps. However, continued iterations of the
atmosphere and ice models reveal a stagnation of the ice sheet on Baffin
Island, driven by melting due to warmer temperatures at the margins of the
ice caps. This warming is caused by changes in the regional circulation that
are forced by elevation changes due to the ice growth. A stabilizing feedback
between ice elevation and atmospheric circulation thus prevents full
inception from occurring.
Type of Medium:
Online Resource
ISSN:
1814-9332
DOI:
10.5194/cp-14-1441-2018
DOI:
10.5194/cp-14-1441-2018-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2217985-9
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