Global Climate Impacts of Greenland and Antarctic Meltwater: A Comparative Study
Name
clim-JCLI-D-22-0433.1.pdf
Description
Published version
Size
9 MB
Format
Adobe PDF
Checksum (MD5)
804c70c615444ba67f0575c9d386cba7
Author(s)
Li, Qian
Marshall, John
Rye, Craig D
Romanou, Anastasia
Rind, David
Kelley, Maxwell
Date Issued
June 1, 2023
Journal
Journal of Climate
Publisher
American Meteorological Society
Citation
Li, Q., J. Marshall, C. D. Rye, A. Romanou, D. Rind, and M. Kelley, 2023: Global Climate Impacts of Greenland and Antarctic Meltwater: A Comparative Study. J. Climate, 36, 3571–3590.
Version
Final published version
Abstract
Both the Greenland and Antarctic ice sheets have been melting at an accelerating rate over recent decades. Meltwater from Greenland might be expected to initiate a climate response that is distinct, and perhaps different from, that associated with Antarctic meltwater. Which one might elicit a greater climate response, and what mechanisms are involved? To explore these questions, we apply climate response functions (CRFs) to guide a series of meltwater-perturbation experiments using a fully coupled climate model. In both hemispheres, meltwater drives atmospheric cooling, sea ice expansion, and strengthened Hadley and Ferrel cells. Greenland meltwater induces a slowdown of the Atlantic meridional overturning circulation (AMOC) and a cooling of the subsurface ocean in the northern high latitudes. Antarctic meltwater, instead, induces a slowdown of the Antarctic Bottom Water formation and a warming of the subsurface ocean around Antarctica. For melt rates up to 2000 Gt yr−1, the climate response is rather linear. However, as melt rates increase to 5000 Gt yr−1, the climate response becomes nonlinear. Due to a collapsed AMOC, the climate response is superlinear at high Greenland melt rates. Instead, the climate response is sublinear at high Antarctic melt rates, due to the halting of the northward expansion of Antarctic sea ice by warm surface waters. Finally, in the linear limit, we use CRFs and linear convolution theory to make projections of important climate parameters in response to meltwater scenarios, which suggest that Antarctic meltwater will become a major driver of climate change, dominating that of Greenland meltwater, as the current century proceeds.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1175/JCLI-D-22-0433.1
