James Morison of the University of Washington—principal investigator for the North Pole Environmental Observatory—takes samples from a hole drilled through the Arctic sea ice. Credit: National Science Foundation

Sitting atop one axis of the Earth, the North Pole is located at the junction of ocean and atmospheric currents that affect global climate. Observations in recent years have shown a rapid thinning of sea ice in the Arctic Ocean and shifts in ocean circulation around the world that are related to a pattern of change in the atmospheric circulation of the Northern Hemisphere—known as the Arctic Oscillation—which is roughly centered at the North Pole.

Arctic Ocean circulation and the water flowing from the Arctic into the Greenland Sea affect the deep circulation of the Atlantic Ocean and thus play an important role in regulating climate. To more closely observe and understand such changes, an international scientific team supported by NSF has established a polar research camp known as the North Pole Environmental Observatory (NPEO).

Led by oceanographer James Morison of the University of Washington, NSF-supported scientists from Oregon State University, as well as others supported by the National Oceanic and Atmospheric Administration (NOAA), the Naval post-graduate school, and the Japan Marine Science and Technology Center, are conducting an array of experiments at the North Pole to understand this little known, but extremely important region.

For the past five years, NSF has supported an international and interagency team of researchers led by investigators at the University of Washington, who are studying the physical properties of the Arctic Ocean and the potential effects of changes in the Arctic on global climate. Credit: Trent Schindler, National Science Foundation

In addition to the logistical challenges of establishing a world-class observatory in such harsh conditions, the scientific and logistical teams regularly contend with the challenges of scuba diving in the icy Arctic Ocean and keeping an ever-watchful eye out for polar bears. Since there is no land mass directly over the North Pole, scientists must constantly gauge shifting conditions of the sea ice beneath them. A frozen-solid ice pack one day may give way to open water the next.

To collect year-long information about ice thickness and movement, water temperature and salinity, and the speed and direction of underwater polar currents, the team deploys a system of floating buoys on a mooring line that stretches more than two-and-a-half miles from the bottom of the Arctic Ocean, to within feet of the constantly shifting polar ice pack. That's longer than Mt. Rainier is high.

Teams of scientists also drill through ice—often more than 12-feet thick—to install buoys that measure air temperature through the ice cover. Imbedded in the ice automated sensors that send detectors on hundred-mile treks—from the North Pole to Greenland, for example—to measure heat fluctuations in the upper ocean. Even subtle changes in air and water temperature can mean large variations in the thickness of ocean ice.

In order to measure changes in seawater chemistry, Morison and coworker, Kelly Falkner of Oregon State University, sampled water nearly a mile below the ocean surface—from an aircraft.

Even using submarines and icebreakers, it is difficult to obtain long-term measurements of temperature and other important climate variables at the North Pole. NEPO’s drifting research stations are designed to provide a mix of coverage over time and in a wide geographic area.

"The observatory really fills a hole in our scientific observations," says Morison. "The station, and others like it, will provide a set of data taken reliably over a long period as a benchmark for the study of climate change."