Satellite woes hurt climate research

US researchers who hoped to use new weather satellites to gather long-term climate data may be able to look to other countries to pick up the slack now that defense officials have scaled back plans for the program.

The multi-billion dollar National Polar-orbiting Operational Environmental Satellite System (NPOESS) is intended to improve weather forecasts for civilian and military use. Climate scientists have also seen it as a source of data for longer-term research.

But the mission has been subject to repeated delays and escalating costs since its inception in 1994 and is now running 5 years behind schedule. When its total budget recently grew to $11.5 billion, it triggered a statutory review required when any Department of Defense-funded program runs more than 25% over budget.

The upshot of that review was a decision to reduce the number of satellites in the program and eliminate five sensors, three of them related to climate research. The House Science Committee discussed these issues at a hearing last week (June 8).

"The problems of NPOESS have really set back the climate observation system that we had really hoped for," said Warren Washington, senior scientist at the National Center for Atmospheric Research in Boulder, Colorado. "We really need something that gives us global coverage of the trends."

Washington said researchers viewed the decision as a heavy blow, but thought that it would be possible to fill in the gaps by using data from other satellites, including some from other countries.

"This is going to be a difficulty facing the community, doing something to continue these very important measurements," said John Christy, director of the Earth System Science Center at the University of Alabama in Huntsville. "It's looking pretty bleak at the moment. The implication is that another agency is going to have to step in and provide a filler."

Documentation for yesterday's meeting makes it clear that the downsizing of the project will also be bad news for weather forecasting. For example, work on one of the key weather sensors that is behind schedule -- the Conical Microwave Imager/Sounder (CMIS) -- will be stopped.

The Pentagon said a new sensor with some or all of CMIS's intended capabilities would be developed, but would not be ready for the initial NPOESS satellite. In the meantime, documents for the House Committee meeting note, "the U.S. will have to rely temporarily on the Europeans for data that was to be collected by CMIS, including ocean wind speeds."

Among other losses are proposed sensors to measure solar and Earth electromagnetic radiation which would have allowed scientists to measure different wavelengths in the same geographic location simultaneously.

"The main thing that we're going to lose for sure is the simultaneity of outputs," said Christopher Ruf, associate professor of Atmospheric, Oceanic & Space Sciences from the University of Michigan, Ann Arbor. In terms of short-term weather forecasting, the area that loses out the most "is extreme weather events?where things are evolving quickly you get most added value from simultaneous measurements of the same piece of real estate."

Ruf said it isn't yet clear how the dust will settle on the issue, but said "the best case scenario is that we stay in place and don't go backwards."

If the US satellites are launched without the climate sensors, then the international community will do its best to make up for it, said Stephen Briggs, head of the Earth Observation Science and Applications Department at the European Space Agency.

There are already a number of international partnerships for coordinating and exchanging climate data, he said. These include the Committee on Earth Observation Satellites (CEOS) whose members include 25 national agencies which monitor the earth using satellites. The United Nations' Global Climate Observing System (GCOS) coordinates information on climate-related issues.

At the moment, CEOS is developing a response to the UN agency's requirements for satellite observation, to feed into the UN's Framework Convention on Climate Change, Briggs told The Scientist. Those requirements include measurements such as aerosol detection, which were originally to have been included on the NPOESS satellites.

"Clearly no one agency will be able to supply the whole gamut of requirements," he said. Any monitoring that is cut from US plans could be made up elsewhere, he added. "We would certainly look for other ways to make up that information."

Briggs said he could "certainly imagine" that US scientists were concerned about the dropping of environment sensors from NPOESS. Still, he added, "the community of space agencies will try to provide as complete a solution as possible to the requirements of GCOS."

Stephen Pincock
spincock@the-scientist.com

Links within this article

M. Fabey, "USAF Cuts Weather-Sat Capabilities To Keep Program Moving," Defense News, June 7, 2006.
http://www.defensenews.com/story.php?F=1855395&C=america

NPOESS
http://npoess.noaa.gov/

Revised weather satellite program to be examined at hearing with agency heads
http://www.house.gov/science/press/109/109-274.htm

House Science Committee Hearing Charter: The Future of NPOESS: Results of the Nunn-McCurdy Review of NOAA's Weather Satellite Program
http://www.house.gov/science/hearings/full06/June%208/charter.pdf

Warren M. Washington
http://www.cgd.ucar.edu/ccr/warren/

John Christy
http://www.atmos.uah.edu/atmos/christy.html

Committee on Earth Observation Satellites
http://www.ceos.org/pages/overview.html

GCOS: Systematic observation requirements for satellite-based products for climate (Draft version)
http://www.wmo.ch/web/gcos/GCOS_SatReq_for_Climate_v1.1_REVIEW.pdf

Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC
http://www.wmo.ch/web/gcos/GCOS_SatReq_for_Climate_v1.1_REVIEW.pdf