Fifty seconds after the release code was transmitted through the ice, the float and instrument at the top of the mooring hit the frozen surface below the feet of University of Washington scientists and engineers. About 40 minutes later, the final floats hit the ice carrying the tail end of the cable and instruments from a mooring anchored to the seafloor for a full year, eight times longer than the only previous mooring at the pole.
Retrieving the first year-round mooring ever used at the North Pole was among the challenges facing researchers April 18-28 during the third year of work under the National Science Foundation's North Pole Environmental Observatory program.
In addition to recovering the mooring, 14 polar scientists and engineers installed a new mooring and, as in the past two years, they deployed a fleet of sophisticated drifting buoys on the ice and conducted surveys of water conditions across hundreds of miles.
Third year of 5-year program
The work April 18-28 is
part of a 5-year, $3.9 million project funded by the National Science
Foundation to take the year-round pulse of the Arctic Ocean and learn how
the world's northernmost sea helps regulate global climate.
Since the 1980s scientists have seen arctic waters warm and the ice pack thin. The magnitude and rapid speed at which these changes occurred surprised many scientists and heightened concern that more radical changes are possible. At the 2001 camp last spring the ice was so broken up that researchers had trouble finding a place to establish a camp near the North Pole.
Computer modelers say the trends fit how the Arctic could respond to warming caused by the buildup of greenhouse gases. Still, the changes might simply be part of a natural cycle.
Contacts:
-- James Morison, leader of the observatory and an
oceanographer with the University of Washington's Applied Physics
Laboratory – Morison was on the ice this year – (206) 543-1394, morison@apl.washington.edu
-- Michael Ledbetter, Arctic System Sciences Program manager, National
Science Foundation – (703) 292-8029, mledbett@nsf.gov
Scientists from UW, NOAA, CRREL, Japan, OSU and Naval Postgraduate
School
The North Pole Environmental Observatory program
involves researchers and engineers from the University of Washington,
NOAA's Pacific Marine Environmental Laboratory in Seattle, Army's Cold
Regions Research and Engineering Laboratory in Hanover, N.H., the Japanese
Marine Science and Technology Center in Yokosuka City, Oregon State
University and the Naval Postgraduate School in Monterey, Calif.
Retrieving mooring
A preliminary check of instruments
recovered last month showed that all the instruments appear to have
collected data for the full year they were anchored in 4,300 meters (2.7
miles) of ocean about 30 miles from the North Pole. The top of the mooring
was beneath the ice and couldn't relay data to scientists via satellite,
unlike the observatory's drifting buoys that routinely broadcast
information to researchers.
The upper 1.6 miles of cable and instruments from the mooring were recovered. Left on the seafloor was the anchor and lower mile or so of cable, where there were no instruments. Once floats brought the mooring up under the ice, divers entered the water to attach a retrieval line and researchers worked seven to eight hours hauling cable and instruments out of a 4-foot-wide hole melted in the ice.
Instruments on the mooring included: seven conductivity-temperature recorders to measure the warming, cooling and salinity changes in different layers of the ocean; four current meters to measure speed and direction of flow; an acoustic doppler current profiler to provide detailed information on the vertical structure of the ocean currents, as well as the ice drift; and an upward-looking sonar to measure ice thickness.
Among other things the instruments were monitoring the condition of the upper 400 meters (1,300 feet) of the ocean looking, for example, at differences between the cold halocline, a layer within about 150 meters (500 feet) of the surface that's as cold as minus 2 degrees Celsius, and the layer found generally 200 to 400 meters (700 to 1,300 feet) from the surface that is 3 to 5 degrees warmer. The presence of the low-salinity halocline is a key to ice formation, since it acts as an insulating lid, keeping the much-warmer underlying layer away from the ice.
Scientists are interested in detecting changes that might mean the water in these layers is changing or mixing, something that could greatly affect ice formation.
The mooring recovered last month was replaced with a new mooring for the coming year. The only previous such mooring at the North Pole was in place for only 1½ months in 1979.
Contacts:
-- Knut Aagaard, oceanographer with UW's Applied
Physics Laboratory – Aagaard was on the ice this year – (206) 543-8942, aagaard@apl.washington.edu
-- Rebecca Woodgate, oceanographer with UW's Applied Physics Laboratory –
did not go to the Arctic – (206) 221-3268, woodgate@apl.washington.edu
-- Richard Moritz, an oceanographer with the UW's Applied Physics
Laboratory, is the principal investigator for the upward looking sonar
portion of the program – did not go to the Arctic – (206) 543-8023, (206)
543-6613, dickm@apl.washington.edu
2002 is third year for drifting buoys
The eight main
buoys deployed as part of the North Pole Environmental Observatory were
installed 50 to 80 meters (165 to 265 feet) from each other in an ice pan
10 feet thick, the best ice floe of the last three years. A ninth buoy was
deployed 300 miles away.
The thickness of the ice was a concern because last year's ice was so unkind to two buoys. Almost like a giant pair of scissors, ice at one point sheared off instruments that were taking ocean measurements beneath the Japanese buoy but left the instruments and parts above the water operational. And the U.S. meteorological buoy lasted only a couple of weeks.
The buoys all drift with the pack ice around the pole and out toward the Atlantic Ocean transmitting information via satellite about ice motion, ice thickness, upper ocean, weather conditions and the amount of heat reaching the ice from the sun and atmosphere.
New to the observatory is a buoy capable of measuring heat and salinity as it moves from the warmer interior of the ocean up and through the ice. This flux is influenced by mixing in the upper layers of the ocean, which the buoy also will monitor. The Autonomous Ocean Flux Buoy was developed at the Naval Postgraduate School in Monterey, Calif.
Also new is a drifter with a camera connected to the Internet, one of six from NOAA's Pacific Marine Environmental Laboratory of Seattle and the U.S. Army's Cold Regions Research and Engineering Laboratory of Hanover, N.H. The camera relates conditions on the ice to instrument readings. View the images at http://psc.apl.washington.edu/northpole/ or at the NOAA site http://www.arctic.noaa.gov/gallery_np.html. Images are usually updated every six hours although the camera can be used more frequently if needed and can be zoomed.
The other five NOAA and CRREL buoys are a meteorological buoy to measure wind speed, atmospheric pressure and temperature; two radiometer buoys measuring radiation from the sun and long-wave radiation from the atmosphere; and two ice-mass balance buoys measuring ice temperature profiles and snow thickness.
Japanese engineers deployed another Compact Arctic Drifter developed by the Japanese Marine Science and Technology Center. It measures ocean temperature, salinity and currents, atmospheric temperature and pressure, and wind velocity. The use of a J-CAD each year of the North Pole Environmental Observatory amounts to a $2.5 million contribution (during five years) of equipment from Japan.
The ninth buoy from the International Arctic Buoy program measures atmospheric pressure and was deployed 300 miles from the other eight.
Contacts:
-- Jim Overland, oceanographer with NOAA's Pacific
Marine Environmental Lab, Seattle – Overland did not go to the Arctic –
(206) 526-6795, overland@pmel.noaa.gov
--
James Morison, leader of the observatory and an oceanographer with the
UW's Applied Physics Laboratory – Morison was on the ice – (206) 543-1394,
morison@apl.washington.edu
-- Tim Stanton, associate research professor, Naval Postgraduate School,
Monterey, Calif. – Stanton was on the ice this year –(831) 656-3144, stanton@nps.navy.mil
--
Takatoshi Takizawa, senior scientist, Japanese Marine Science and
Technology Center – Takizawa did not go to the Arctic – 81 468 67 5571, takizawat@jamstec.go.jp
Hydrography surveying includes fine-scale survey of Lomonosov
Ridge
Hydrographic surveys can give insights into broad
changes in the circulation of the ocean.
Using a helicopter instead of a plane this year made it possible for researchers to land at seven spots fairly close to each other across 100 miles of ice for the most-detailed survey ever of the water properties over the Lomonosov Ridge near the North Pole. Only 1,000 meters below the surface in places, the Lomonosov is the Arctic Ocean's shallowest major ridge. It's of interest because, among other things, two branches of warmer waters from the Atlantic may travel along the ridge before exiting the Arctic along the east coast of Greenland. Whether they mix or remain separate are among the unknowns. It also appears that the ridge is one of the places where these warmer waters spread to deeper basins.
Researchers also flew to two sites hundreds of miles away to gather samples in the poorly sampled Makarov Basin, one of the places where waters from the Pacific and the Atlantic oceans meet.
At each station over the Lomonosov Ridge and in the Makarov Basin, researches lowered an instrument to measure temperature, salinity and dissolved oxygen gas. In addition, scientists at the Makarov Basin sites and the base camp took water samples that will be analyzed for trace chemicals at Oregon State University in order to determine the sources of the water collected.
Contacts:
-- James Morison, oceanographer with the UW's APL –
Morison was on the ice this year – (206) 543-1394, morison@apl.washington.edu
-- Michael Steele, oceanographer with the UW's Applied Physics Laboratory
– Steele did not go to the Arctic – (206) 543-6586, kfalkner@oce.orst.edu
Privately operated Borneo is home base
The North Pole
Environmental Observatory program was staged this year from a privately
operated camp, dubbed Borneo, that is established each April near the pole
for tourist and commercial enterprises from France, Russia, Canada and
Norway. While tourists cross-country skied to the pole and rode hot-air
balloons, observatory researchers used the station as the starting point
for their various projects. The place where scientists returned to
retrieve the mooring, for example, was 60 miles north of Borneo. Two 8- x
12-foot tents, mounted on sleds, were installed there as living and
workspace.
As in past years, staging and logistics were possible with the generous cooperation and support from the Canadian Forces Station Alert, part of the Canadian Department of National Defence, as well as the Defence Research Establishment Atlantic.
The program contracted with First Air out of Resolute Bay and Great Slave Helicopter out of Yellowknife for air support; with Narwhal Arctic Services for ground support at Resolute Bay; and Cerpolex out of Paris for camp support on the ice at Borneo.
Images for news media use only.
The
University of Washington's Paul Aguilar, wearing a special dry suit to
withstand water a chilly 28 F, was a member of a team of divers who went
under the ice to locate and attach a retrieval line to a mooring being
recovered from near the North Pole. Photo credit: University of
Washington/James Johnson
An instrument that monitors ocean currents emerges from the ice as University of Washington's Jim Johnson, Paul Aguilar and Knut Aagaard work to retrieve a mooring from where it was anchored on the ocean floor near the North Pole since last year. Photo credit: University of Washington/Eric Boget
Once the mooring at the North Pole was released from the lower portion of its cable and anchor, floats pulled it to the surface where 1.5 miles of cable loaded with instruments trailed along under the ice waiting to be pulled out of a hole in the ice. Divers in special dry suits went under the ice to attach the initial retrieval line to the mooring and were on standby if floats or instruments had become tangled beneath the ice. Graphic credit: University of Washington/James Johnson
The University of Washington's Knut Aagaard prepares instruments that measure salinity and temperature to go on a mooring installed on the seafloor near the North Pole in place of a mooring with instruments that had been recording data for the past year. Photo credit: University of Washington/Paul Aguilar
The University of Washington's James Morison, leader of the North Pole Environmental Observatory, works inside a makeshift tent steadying sampling equipment as it is lowered into the Arctic Ocean through a hole in the ice. (Note this image is from the 2001 camp.) Photo credit: Oregon State University/Kelly Falkner
