ICE-thermometers. Check. Ice-ocean buoys. Check. Mobile scientific station. Check.Susumu Honjo's tanned face beams with excitement as he oversees the loading of his environmental research equipment onto the Polar Star, a United States Coast Guard icebreaker docked in Boston Harbor. Dr. Honjo, co-chief scientist aboard the ship, is preparing for the first International Arctic Ocean Expedition to the North Pole. Though it is only June, the ship is about to set sail for Tromso, Norway, where it will join the German Polarstern and the Swedish Oden, also icebreakers, during the first week of August, for a 70-day journey to the top of the world. More than 100 scientists from at least seven countries - Canada, Germany, Japan, Norway, Sweden, the United Kingdom, and the United States - will coordinate efforts to study the effects of global climate change. "Arctic studies are extremely important right now because of the greenhouse warming [effect]," says Honjo, who is a senior scientist at the Woods Hole (Mass.) Oceanographic Institution. "The Arctic Ocean environment can be the best precursor of climate change," Honjo says. "A 1 degree change in Boston translates to a 5 to 7 degree change in the Arctic. It is regarded as the best outdoor laboratory" for measuring the effect of so-called greenhouse gases on the Earth's atmosphere. Although the full extent of environmental warming cannot be studied during the expedition, two ice-ocean environmental buoys carried by the Polar Star will be installed so that data can be collected long after the scientists leave. These buoys, 51 inches in diameter and 60 inches tall, will support a series of instruments extending 100 meters (328 feet) under the ice. They will measure everything from the change in ice thickness to plankton concentration of the sea water. Each is an unmanned biological station, doing the work of 15 people. "These are similar to satellite probes sent into space but even better," Honjo says. The buoys were designed and constructed by Honjo and his colleagues at Woods Hole in cooperation with scientists from the Japan Marine Science and Technology Center in Yokosuka, Japan. "Buoy computers will send satellite messages and feed information to Woods Hole, the Office of Naval Research in Washington, D.C., the University of Hamburg, and Yokosuka [Japan] in real time," Honjo says. Buoy data will be available to scientists worldwide, at any time, via a computer network system. Information will appear on computer screens as it is collected - every 15 minutes day and night for at least the next 18 months. In addition to the two large buoys, 12 smaller ones supplied by the Germans and the US Navy, weighing 300 pounds each, will be located in the area. The whole system will reach 300 kilometers (186 miles) from north to south, creating a diamond shape. Heinrich Hoeber, professor of meteorology at the Hamburg University Meteorological Institute, will view the data from Hamburg, as soon as the buoys are in place. "We [the Germans] are looking at computer models that will predict future weather conditions, called climate modeling," Dr. Hoeber says. These models should be able to predict how carbon dioxide increase in the atmosphere influences weather patterns on Earth. "By and large, models already exist ... but the role ice plays isn't well understood," he says. "Weather and climate are completely different if we put an ice sheet on the ocean or not because it impedes exchange between the ocean and the atmosphere," Hoeber says. "The ice is like a lid on the ocean.... If there is no ice, just open water, waves and currents develop in the ocean, winds change, pressure systems change." The ice data transmitted by the buoys should help make the role of ice in climate change clearer. "The atmosphere acts as a whole system," Hoeber says. What happens at the North Pole is not just a local effect - it's global, he says. The Arctic Ocean is so influential in terms of the climate, Honjo says, that if the arctic ice disappeared, it could determine the fate of the entire planet. If the air temperature goes up, more sea water is exposed as the area covered by ice shrinks. When the water temperature is high compared with that of the air, the water will warm the air even more. "Once you start to raise the temperature of the earth, the Arctic Ocean becomes warmer and warmer, and there is no way to stop it," Honjo says. Besides global warming studies and computer modeling, the scientists will undertake a number of other experiments. One concerns the transpolar drift. "The Arctic is actually a big pond, surrounded by forest material and a vegetarian environment," Honjo says. Fresh-water rivers from Siberia, Canada, and Alaska carry nutrients from the residue of agricultural and industrial activities occurring around these rivers into the Arctic Ocean. "This could be the reason for the tremendous fish catches around Iceland and even farther to the south. Even some part of the high fertility of the North Atlantic [Ocean] may be a gift from the Siberian soils," Honjo says. For another study, a 40-foot long and 4-inch wide coring system aboard the Polar Star will drill into the ocean's bottom to study the history of the Arctic. Scientists believe that because of the age of the area, and the millions of years of carbon from organisms building up on the bottom of the ocean, there is a potential for a 3-trillion-cubic-foot reserve of natural gas under all that ice. Before this resource can be tapped safely, researchers need to understand the relationship of the Arctic Ocean to the overall ocean system. Even though three of the most powerful icebreakers in the world are joining forces, the trip will still be challenging. One icebreaker alone could easily get stranded going that far north, Hoeber says. Once a ship gets deep into the ice, strong support is needed. With all three ships, the expedition has a good chance of reaching the North Pole and accomplishing its research goals. But success will depend on the condition of this year's ice. "We only have a 70-day window to get in and out," Honjo says, before the ice becomes too thick to navigate. Two scientists from Canada will help guide the ship through the frozen water. Caren Garrity, remote-sensing specialist with the Microwave Group in Ottawa, and Kenneth Asmus from the Canadian government Atmospheric Environmental Services, also in Ottawa, will use the ice-mapping equipment at the Ottawa office to help navigate the ship. "Everything emits microwaves, you, me, and even the ice," Dr. Garrity says. "By measuring the natural microwave emission from the ice by satellite we can tell what kind of ice it is." It is important to keep the ship away from the "multi-year" ice - ice that has survived at least two summers' melt, Garrity says. This is the hardest and thickest ice, requiring too much fuel to break through. The older the ice, the less saline it is because salt is released during the summer melts. Ice that is less saline is harder to crush. ICE has different ages, Garrity says. "Thin" ice is less than 10 centimeters (3.94 inches) thick, having just formed that year, and doesn't require much effort to plow through. "First" year ice may be as much as two meters thick (6.56 feet), but is still navigable. "Old" ice, which has survived at least one summer, and multiyear ice are to be avoided if possible, Garrity says. "We have lots of eggs in one basket because this [North Pole expedition] is very expensive and we can't do this any time we want," Honjo says. "But the research needs to be done." The idea for the trip was originated by Sweden, Hoeber says, which had just built a new icebreaker and was anxious to put it to the test. The Swedes contacted polar scientists in several countries asking for their participation in a research expedition. When the scientists heard about the idea, they all said "Oh yes! Let's go!" Currently, only the Soviets, who have not yet said they will join the expedition, make regular trips to the top of the world in their nuclear-powered icebreakers. They even offer trips to tourists for fees ranging from $25,000 to $30,000 a person.