Photo Credit: Michael Studinger/NASA

The edge of the Larsen Ice Shelf on the eastern side of the Antarctic Peninsula. Parts of the ice shelf have disintegrated over the last 20 years. Scientists recently met to discuss the latest research on this and other parts of West Antarctica, which is expected to contribute to sea-level rise in the coming century.

The West Antarctic Ice Sheet (WAIS) Initiative focuses on two key questions: How will the West Antarctic ice sheet affect future sea level? And how do rapid global climate changes occur?

At the 18th annual WAIS Initiative workshop, held near Loveland, Colo., last month, it was apparent those questions are still at the forefront, but new technologies and techniques are bringing scientists ever closer to understanding Antarctica’s complex ice dynamics and its role in the global climate system.

Ted Scambos noted that researchers must embrace a wide variety of disciplines to understand the interaction between the ice, ocean and atmosphere — three processes involved in a complex dance that’s warming much of West Antarctica and causing glaciers to flow faster to the sea, which ultimately raises sea level.

“We still want to further underscore the value of multidisciplinary research into the West Antarctic Ice Sheet. It’s clear that things like atmosphere-ice and ocean-ice interactions are going to be key to understanding how it’s changed in the past, how it’s changing in the present, and what’s going to happen in the future,” said Scambos, lead scientist at Boulder’s National Snow and Ice Data Center (NSIDC) .

NSIDC hosted this year’s meeting, attended by nearly 100 glaciologists, geologists, meteorologists and other others, including many early-career scientists. The workshop, partly supported by the National Science Foundation’s Office of Polar Programs (OPP) , involved about 2½ days of presentations and discussions, ranging from the latest observations made from satellites and aircraft to some of the upcoming expeditions to Antarctica.

Several of the presentations ranged well outside the Antarctic, spanning the globe to Greenland, which is also undergoing dramatic changes, to places where one wouldn’t think to go in a meeting dedicated to ice and snow.

“The tropics are a bigger player than we thought,” said Ryan Fogt , an assistant professor of meteorology at Ohio University , who was one of the workshop’s keynote speakers.

Fogt has a grant from NSF to understand the warming under way in West Antarctica and the Antarctic Peninsula, and the associated loss of sea ice, from a meteorological point of view. He believes a persistent low-pressure system, influenced by large-scale climate modes like the El-Niño Southern Oscillation (ENSO) , plays a role because it helps sustain the circulation pattern that leads to warming in the region. [See previous article: Record extent.]

“[The Antarctic is] connected to the rest of the globe,” observed Eric Steig , a professor at the University of Washington in Seattle , whose presentation also focused on influences to West Antarctica from the tropical Pacific Ocean. Not only does the Antarctic react to changes farther north, but it “pays it forward” in changes to sea level and ocean circulation, according to Steig.

His research with colleagues, published earlier this year in the journal Nature, suggests that rising sea surface temperatures in the area of the Pacific Ocean along the equator and near the International Date Line drive atmospheric circulation that has caused some of the largest shifts in Antarctic climate in recent decades. [See previous article: Heat wave.]

There were the usual debates played out among such presentations: What exactly is causing the changes in the atmosphere above Antarctica that is strengthening westerly winds, which are drawing relatively warm circumpolar deep water (CDW) onto the continental shelf? Is it influenced by the tropics or ozone depletion in the stratosphere? Most everyone agrees that the CDW is responsible for weakening the ice shelves that hold back the glaciers from below.

NASA scientist Robert Bindschadler and his field team will begin taking a look at that process this upcoming season in West Antarctica. The researchers will land by helicopter on the Pine Island Glacier Ice Shelf where they’ll melt a hole 600 meters deep through the ice before deploying instruments into the ocean cavity below. They hope to get data on what’s happening between the ice and water. [See previous articles: Cracking the case and Dress rehearsal.]

“The objective still is quantifying the contributions to sea level from the West Antarctic Ice Sheet,” Bindschadler said during a discussion about the WAIS Initiative’s research priorities looking forward to the future.1 2   Next