PNAS Publication Highlights CReSIS Researcher's Accomplishment


By Shawn Schaller
Summer 2011

Stephen Price’s paper “Committed sea-level rise for the next century from Greenland ice sheet dynamics during the past decade,” was published in the May 17, 2011 issue of Proceedings of the National Academy of Sciences of the United States of America (PNAS). Dr. Price, a scientist with the Fluid Dynamics and Solid Mechanics Group at Los Alamos National Laboratory, is also an active CReSIS partner.

“Relieved,” was the only word Price found to describe his feelings on his accomplishment. “We've been trying to get the… results from this paper published for a while now but had problems even getting the editors to send it out for review.”

Whether he admits it or not, Price should also be proud of both his paper’s content and its success. According to the PNAS website, the serial is one of the most heavily-cited scientific journals in the world

In Price’s defense, a certain amount of relief is due as well. He and his associates, Anthony Payne, Ian Howat and Ben Smith, had worked on this particular bit of research and the resulting paper for more than a year.

Steve Price

Photo 1: CReSIS researcher Steve Price, from the Los Alamos National Laboratory, recently had his paper on the Greenland ice sheet published in the PNAS scientific serial.

“We still have a long way to go before we have rigorous predictions from improved ice sheet models,” said Price on the overall outlook of his paper. “But… those models are coming along and can provide some useful insight now.”

According to an article entitled “Greenland ice in no hurry to raise seas” by New Scientist environment reporter Michael Marshall, Price’s precise modeling of the Greenland ice sheet allowed him to make a more physically based prediction of Greenland’s potential contribution to future sea level. Price’s prediction for sea-level rise from changes in the flow of Greenland’s outlet glaciers is approximately 1/2 of a widely cited previous prediction, which focused on estimating an upper bound for sea level rise by the year 2100.

In his paper’s abstract, Price says that he and his partners’ three-dimensional model of the Greenland ice sheet precisely simulates the ice sheet’s mass losses during the past decade. The model then projects the simulation through the remainder of the century, producing an estimate for the ice sheet’s minumum contribution to future sea level rise.

Greenland model

Photo 2: Figure from Price's paper compares elements used to construct his new model of the Greenland ice sheet.

This estimate, referred to by Price and his associates as “committed sea level rise,” is only a base prediction because it does not account for future changes in the dynamics of the ice sheet, which is, according to Price, an unlikely occurrence. He and his associates went on to present an upper bound estimate that accounts for a reasonable amount and type of dynamic perturbations through the end of this century.

“The model [allows] for a more complicated momentum balance than the ‘pre-AR4’ models,” Price said on the most fundamental difference between his work and similar previous research. “This paper shows that you can get realistic dynamic behavior from your model only when that model is solving the ‘right’ system of equations.”

To Price, it’s not about the ability to make exact predictions right away; it’s about using his new model to inspire more advanced, accurate models down the road.