A new modeling framework helps understand consequences of future sea-ice loss in the Arctic.
Lawrence Livermore National Laboratory scientists in the Atmospheric, Earth and Energy Division developed a novel method for isolating the impacts of high latitude sea-ice loss by sampling the uncertainties in selected sea-ice physics parameters. Their research shows that Arctic sea-ice loss of the magnitude expected in the next few decades could substantially impact California’s rainfall thus exacerbating future California droughts.
Previous studies have suggested that California’s drought has a manmade component arising from increased temperatures, with the likelihood of such warming-enhanced droughts expected to increase in the future. This study highlights yet another pathway by which human activities could affect the occurrence of future droughts over California - through Arctic sea-ice loss. The study also suggests that the ability of Earth system models to accurately estimate future precipitation changes over California may be linked to the fidelity with which future sea-ice changes are simulated.
The dramatic Arctic sea-ice loss observed over the satellite era has intensified debate into whether these high latitude changes are affecting weather and climate outside of the Arctic. Many previous attempts to demonstrate statistically significant remote responses to sea-ice changes have been hindered by factors such as large high latitude variability and short observational datasets. In this study, a new modeling framework, involving sea-ice physics parameter perturbations, was developed to isolate the climate response arising from changes in Arctic sea-ice cover alone.
Performed simulations indicate that the loss of Arctic sea-ice cover drives the formation of a high pressure ridge in the North Pacific - much like the ridges that have been pushing the winter storm systems away from California during the 2012-2016 drought. In a two-step teleconnection, sea-ice changes lead to reorganization of tropical convection that in turn triggers an anticyclonic response over the North Pacific, resulting in significant drying over California. The mechanism behind this teleconnection appears to be robust to the source of high-latitude sea ice changes: it is shown that Antarctic sea ice loss can also trigger substantial precipitation changes over California.
This research indicates that substantial loss of high-latitude sea-ice cover is highly likely to have significant far-field effects, and can impact California’s precipitation through atmospheric teleconnections involving tropical convection changes.
Contacts (BER PM)
This work was supported by the Climate and Environmental Sciences Division and the Regional and Global Climate Modeling Program of the U.S. Department of Energy (DOE) Office of Science and was performed under the auspices of the Lawrence Livermore National Laboratory (contract DE-AC52-07NA27344). I.C. and C.B. were supported by the DOE Early Career Research Program Award SCW1295. D.D.L. was supported from the DOE Office of Science through the SciDAC project on Multiscale Methods for Accurate, Efficient, and Scale-Aware Models of the Earth System. IM release number: LLNL-MI-740787.
Cvijanovic I., B.D. Santer, C. Bonfils, D.D. Lucas, J.C.H. Chiang, and S. Zimmerman. “Future loss of Arctic sea-ice cover could drive a substantial decrease in California’s rainfall.” Nature Communications 8, Article 1947 (2017). [DOI: 10.1038/s41467-017-01907-4]
SC-23.1 Climate and Environmental Sciences Division, BER
BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER
May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]
May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]
May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]
May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]
Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]
List all highlights (possible long download time)