Far North Science

Instrument clusters near Barrow gather climate
change data to help tweak computer models
Credit: Mark Ivey

To help tune up the supercomputing climate models that forecast global warming, Sandia National Laboratories of hot New Mexico has been running a unique atmospheric observatory on the frigid tundra of Alaska’s Arctic coast.

Mark Ivey and Bernie Zak operate two research arrays that gaze into the sky to gauge how clouds influence the Earth’s natural greenhouse gas processes — how they act to insulate and keep heat from radiating into space, how the clouds might also reflect solar radiation away from the Earth.

At stake are some of the most fundamental questions about the greenhouse effect, in one of the most important studies of the International Polar Year.

Sorting out the role played by clouds in the global warming drama now underway is one of the most crucial tasks for atmospheric scientists. Many supercomputing climate programs — the models of future climate used by organizations like the Intergovernmental Panel on Climate Change — don’t calculate the influence of clouds as well as scientists would like.

So, with sponsorship by the federal Department of Energy, the Atmospheric Radiation Measurement (ARM) Climate Research Facility built the two research observatories on the northern fringe of Alaska’s Arctic slope. One was constructed 10 years ago near the Chukchi Sea outside Barrow. A smaller facility was built two years later 70 miles inland near the village of Atqasuk.

In the clear, frigid air, the sensors have been building one of the most successful sets of measurements of the Earth’s atmosphere, what Sandia Labs calls “a rare, ground-based window into the cloud and radiative processes that take place in Earth’s atmosphere at high latitudes.”

“The arid cold during winter at the North Slope provides a ‘window’ into space,” says Zak, science liaison for the North Slope site, in a release from Sandia Labs. “Under these conditions, infrared radiant energy can escape more easily through the atmosphere — it’s something that’s part of Earth’s natural energy balance.

“This is one of the ways that high latitudes are quite different from temperate or tropical regions, and reinforces the importance of our research here.”

Sandia researcher Mark Ivey is site manager
for the observatory outside Barrow.
Credit: Eli Mlawer

“Because the North Slope site is fairly cold year-round, we often observe clouds that are composed of ice or ice and water in mixed phases,” says Ivey, North Slope site manager, in a release from Sandia Labs.

The project’s International Polar Year site explains further:

Fundamentally different climate processes—such as planetary heat loss from the poles and extensive sheets of ice that affect solar absorption and sea level—occur at high latitudes compared to other regions. Due to generally cold temperatures, atmospheric water vapor concentrations in the Arctic are quite low, allowing heat energy from the surface to escape through the atmosphere more easily than in less arid environments.

Climate scientists concentrate on Arctic and Antarctic regions because high latitudes are expected to experience the most dramatic change if greenhouse gas concentrations keep rising. During the past 100 years, average Arctic temperatures increased at almost twice the global average rate, and satellite data shows sea ice extent has been shrinking by almost 3 percent per decade.

Residents of Alaska have already experienced warming permafrost, increased coastal erosion, greening tundra, ailing boreal forests, more wildland fires, insect outbreaks and alarming indications that certain ice dependent animals like polar bears have begun to experience stress.