Ocean scientists are enlisting cargo and cruise ships to measure water temperatures, ocean currents and even the height of clouds as the vessels ply their regular routes, in a program that they hope will help reveal some of the oceans' secrets.
"They're going to change our view over the next few years of the way the ocean actually looks," said Peter Ortner, chief scientist with the Atlantic Oceanographic and Meteorological Laboratory of the National Oceanic and Atmospheric Administration.
The long-term data that commercial ships can furnish are what has been historically difficult to obtain, said Thomas Rossby, professor at the University of Rhode Island's Graduate School of Oceanography.
"Presently, we basically depend on archived historical data to make inferences about change over a long time. ... You're hostage to the limited amount of data available in the past," Rossby said.
The volunteer programs are also cheaper, considering that the cost of renting a dedicated research vessel for a single day could exceed $15,000.
Scientists spoke about the project last week at the biannual ocean sciences meeting of the American Geophysical Union.
With instruments affixed this year to the Norrona, a ferry that makes a roundtrip every week stopping in Denmark, Scotland and Iceland, Rossby hopes to learn more about the cold waters emptying out of the Arctic seas into the northern Atlantic Ocean.
Scientists also have been using instruments attached to the cargo ship Oleander since 1992 to monitor the Gulf Stream as the vessel passes between Port Elizabeth, N.J., and Bermuda.
And the Nuka Arctic has been helping since 1999 to give scientists a look at the Gulf Stream along its path between Denmark and Greenland.
With such information regularly collected over a long period of time, researchers hope not just to observe a particular change but to gain an understanding of how the ocean behaves over time, Rossby said.
Working with the University of Miami, cruise ship operator Royal Caribbean International built Explorer of the Seas with oceanographic and atmospheric laboratories for scientists and a science learning center for passengers.
About 60,000 people have attended popular scientists' lectures on the ship, said Rod Zika, professor and chief scientist of the Explorer of the Seas Program at the University of Miami.
"Some people even stay on when they're in port. Rather than go on and buy the trinkets, they stay on to do this," Zika said.
Michael Sheehan, spokesman for Royal Caribbean, said the program started out as a way to give back to the environment but quickly grew to include participation by NOAA and NASA and a program for visiting researchers.
"It's blossomed into something I'm not sure any of us considered at the beginning," he said.