ROCK ISLAND — Data from ice sheets in Greenland and Antarctica support arguments our world is warming, according to NASA scientist Lora Koenig.|
Ms. Koenig, a physical scientist at NASA's Goddard Space Flight Center, shared her observations on the ice sheets -- the massive layer of ice which blankets land masses such as Greenland and Antarctic -- with about 50 people at Augustana College's John Deere Planetarium on Thursday night. She also projected what may be in the ice sheet's future.
"We know the planet's warming," she said. And the threat of shrinking ice sheets, she said, should not be taken lightly because they reflect excess heat and sunlight into space through the albedo effect.
Because Ms. Koenig's work deals mostly with measuring the accumulation of snow on the ice sheets, she has traveled to both Greenland and the Antarctic.
"We want to study the polar regions because the polar regions affect the entire world," she said.
Ice sheets are far from static, she said. They move gradually, like thick honey, before eventually feeding into the ocean through the natural processes of iceberg calving (breaking away) and ablation (melting).
In turn, precipitation must provide enough snow and ice to recoup the lost sheet, she said.
NASA scientists had projected that, during the 21st century, these areas will see 10 and 20 percent more accumulation of ice and snow to offset their losses. But Ms. Koenig said that, on a trip to Antarctica to drill for ice cores, the long cylinders of ice she studied revealed a trend between 1970 and 2010 she termed "slightly negative, and statistically significant."
She also told how she studied an aquifer buried the equivalent of four stories beneath the compacted snow of the Greenland ice sheet. Heavy accumulation obscures the aquifer, she said, providing insulation to preserve the ice at warmer temperatures.
"We had been predicting this ice to be very cold," she said. "But it was quite warm."
NASA estimates the aquifer contains 140 gigatons of water — enough to raise sea levels by .4 millimeters, or the equivalent of "half of a total year of melt" in Greenland, she said.
What concerns Ms. Koenig is that not enough is known about the aquifer to determine of water is filtering into the ocean at an even pace with the melt, or if it poses a risk of draining out into the ocean all at once.
Greenland likely will contribute more to the rising sea level in years to come, she said. That increased carbon dioxide in the atmosphere will pose a threat of further warming at the Poles, Ms. Koenig said.