Second Year Deployment Plan
During April 2001, scientists at a polar ice camp run by the Polar Science Center of the University of Washington's Applied Physics Laboratory will conduct the second installation of the National Science Foundation's North Pole Environmental Observatory, an unmanned suite of instruments gathering weather, ice and ocean information. For the second year of a 5-year program, they will deploy a fleet of drifting buoys and then use a skiplane capable of landing on the ice to hopscotch across hundreds of miles of Arctic ice taking hydrographic measurements. New this year will be a mooring anchored to the ocean floor from which will float more than two miles of instrumented cable for a year.
The work March 27-April 17 is part of a 5-year, $3.9 million project funded by NSF to take the year-round pulse of the Arctic Ocean and learn how the world's northernmost ocean helps regulate global climate. Because the North Pole is so far from shore facilities, measurements in the past have only been made sporadically from manned drifting stations and isolated drifting buoys. Even with submarines and powerful icebreakers, surveys of the area are difficult. The program comes in the midst of observed changes in the Arctic such as the thinning of sea ice and shifts in ocean circulation.
Researchers with NSF projects are from the University of Washington, the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle and Oregon State University. Also participating are scientists and engineers from the Japanese Marine Science and Technology Center in Yokosuka, Japan.
First Year for Ocean Bottom Mooring (Diagram)
The only previous such oceanic mooring near the North Pole was in place for only six weeks in 1979. The mooring being deployed in April will be in place a full year and be replaced each of the next two years for a total of three years of information.
The 9,000 pounds of gear for the mooring includes enough cable to anchor a string of instruments in 4120 meters (2.6 miles) of ocean. Instrumentation includes 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 the detailed vertical structure of the ocean currents, as well as the ice drift; and an upward-looking sonar to measure ice thickness. The instruments will store their data for later retrieval.
Among other things, the instruments will monitor the condition of the upper 400 meters of the ocean, looking, for example, at the differences between the cold halocline, a layer within about 150 meters of the surface that's as cold as minus 2 degrees C, and the layer found generally 200 to 400 meters 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, which is fed by water from the Atlantic, 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. Measurements made as part of the North Pole Environmental Observatory last year, for instance, confirmed that the thickness of the halocline continues to be less than in the past, detected higher salinity in the upper ocean compared to data from 1948-93, and again found the layer of warm Atlantic waters to be warmer by a degree than it was 20 years ago.
The North Pole is a good place to look for changes in the halocline and the layer of warmer water beneath it because significant changes in the ocean and the ice cover are already known to occur there through data gathered by submarines, earlier drifting buoys, and American and Soviet ice stations. A great deal of the water and ice that eventually flows out of the Arctic Ocean passes the North Pole, while the area is close enough to feel the effect of the great trans-arctic current that passes nearby along the Lomonosov Ridge. The abyssal plain at the Pole gives the scientists the flat bottom they are looking for to most easily install the mooring.
Members of the mooring team at the ice camp will be oceanographers Knut Aagaard and Rebecca Woodgate and senior engineer James Johnson, all with the the University of Washington's Polar Science Center.
Second Year for NPEO Drifting Buoys
Six buoys similar to those used last year will be placed on the ice at the North Pole and travel with the ice pack gathering information about ice thickness and the upper ocean. They also will tell about weather conditions and the amount of heat reaching the ice from the sun and atmosphere.
The data gathered from these previously poorly sampled areas of the Arctic can be used in conjunction with satellite and broader sets of meteorological data. Modelers, in particular, are eager to have such "ground truth" information. The measurements collected by the drifting buoys during five years of work also should yield insights about how the Arctic is changing. The buoys should reveal how fast the ice thins, an indication of whether the atmosphere is changing as well.
The buoys relay information continuously via satellite. As expected, the buoys deployed in 2000 moved with the ice across the Arctic Ocean and out Fram Strait into the Greenland Sea. The three that continue to send signals are now about two-thirds of the way down the east coast of Greenland.
Being deployed this year will be:
Information about meteorological conditions, radiation and ice mass will be collected at two places about a kilometer away from each other as part of the observatory. The J-CAD Buoy, which among other things gathers meteorological data, will be grouped with one set of the radiometer and ice-mass buoys.
Members of the drifting buoy team at the ice station will be James Morison (oceanographer) of the UW's APL, Sigrid Salo (oceanographer) with NOAA's Pacific Marine Environmental Laboratory, and Kiyoshi Hatakeyama and Kirokatsu Uno with the Japanese Marine Science and Technology Center.
Second year of NPEO Hydrography Survey will be from Pole 500 km toward Alaska
The third complement of the North Pole Environmental Observatory program is collecting ocean data from five places starting at the pole and traveling for 300 miles toward Alaska. Traveling by ski-equipped Twin Otter, scientists will land on the ice, drill a hole and lower instruments to measure temperature, salinity and dissolved oxygen gas, and take water samples to assess water chemistry.
The information from this "section" can be used to plot a long vertical slice of the ocean that compares measurements over a wide area. Among other things, the information from sections conducted by NSF and other countries can help give insight into broad changes in the circulation of the ocean. Water from both the Pacific and Atlantic oceans make their way into the Arctic. Scientists are interested in such things as the meandering border where these waters meet and begin mixing, a boundary that appears to have shifted dramatically in the late '80s and early '90s, as well as the nature and mixing of layers of water from the two temperate oceans.
Last year's 350-mile section from the North Pole toward Canada was the first-ever conducted in that area of the Arctic Ocean. Although Canadian Forces Station Alert on Canada's Ellesmere Island is the closest human outpost to the North Pole, no section had ever been done before because the ocean between the two has ice that is the arctic's thickest, most broken up and most difficult to travel through or on.
Members of the hydrographic survey team at the ice station will be James Morison (oceanographer) of the UW's APL,and Kelly Falkner (oceanographer) from OSU.
The camp will include an 8 foot by 25 foot hut that will house the crew of and work areas for the mooring program, another 8 by 25 hut that will serve as the command center, housing and kitchen, and an 8 by 16 hut for the Twin Otter crew and work space for the JCAD Buoy. Eleven scientists, engineers and air-crew members are scheduled to be at the ice camp, although only seven or eight will be there at any one time.
The station will be approximately 3 hours by air from Alert. The camp will be served by two Twin Otter aircraft from First Air Inc. . Additionally, a New York 109th Air National Guard C-130 will airdrop fuel and the anchor for the mooring to the station.
The logistics team member at the ice station will be Dean Stewart (field engineer) with the UW's APL. The Polar Science Center's Logistics Manager Andy Heiberg will coordinate the operation from Alert.