SAN FRANCISCO — Commercial satellites, ground-based monitoring stations and airborne sensors can help the U.S. National Weather Service produce more timely and accurate forecasts. But those tools cannot offer the kind of advance notice of severe weather that the National Oceanic and Atmospheric Administration (NOAA) obtains from polar-orbiting satellites, witnesses said March 28 during a hearing of the House Science energy and environment subcommittee.

The White House’s 2013 budget plan delivered to Congress in February requests $2.04 billion for NOAA’s National Environmental Satellite, Data and Information Service out of a total budget for the agency of $5.06 billion. Rep. Andy Harris (R-Md.), chairman of the subcommittee, questioned whether NOAA should place “nearly all of its eggs in a single basket: satellite programs fraught with a long history of major problems.” Lawmakers asked whether some combination of existing and new technology might offer NOAA the same type of data at a lower cost.

Mary Kicza, NOAA assistant administrator for satellite and information services, said satellites are essential because they provide approximately 94 percent of the data NOAA uses in its weather forecasting models. Polar-orbiting spacecraft provide about 84 percent of the data used in those models and geostationary satellites contribute the other 10 percent, she said.

The key contribution of the polar-orbiting spacecraft is their ability to help the National Weather Service forecast severe weather two to five days before it occurs, said John Murphy, National Weather Service chief for plans and programs. That warning gives local officials and emergency response teams time to prepare. When a storm is imminent, the National Weather Service relies on Doppler radar to pinpoint its movement and location, he said.

A panel of witnesses described existing and new technology that NOAA could use to augment its weather forecasting capability. GeoMetWatch Corp. of Las Vegas is eager to sell NOAA data from a commercial, space-based hyperspectral sounder. A hyperspectral sounder was one of two instruments originally slated to fly on geostationary GOES-R satellites but the sensor development program was canceled due to budget concerns. By turning to the private sector, NOAA could acquire highly accurate information on atmospheric water vapor, temperature and pressure “at minimal cost and risk,” David Crain, GeoMetWatch chief executive, said.

Similarly, Bruce Lev, vice chairman of Airdat LLC of Morrisville, N.C., said NOAA weather forecasts would improve dramatically if they included data on the lower atmosphere that his company acquires from hundreds of sensors flying on commercial aircraft. “Despite numerous data-collection systems employed by NOAA, our country is extremely under-sampled,” Lev said.

Berrien Moore, director of NOAA’s National Weather Center and dean of the University of Oklahoma’s College of Atmospheric and Geographical Sciences, said the United States should expand its use of data acquired by disparate networks of ground-based sensors, including 120 stations in Oklahoma.

Nevertheless, all these additional observations would not reduce the need for satellite data, Moore said. “Weather is global; the interests of the United States — including its businesses and its citizens — are global, and hence the U.S. weather observing system must be global. The weather observing system must be a network of networks — satellites, aircraft, balloons and ground-based mesonets,” Moore said.

In addition to employing advanced technology, NOAA and NASA “must find ways to reduce the overall system costs as the current programs are likely unsustainable,” said Eric Webster, vice president and director for weather systems at ITT Exelis of Roanoke, Va., the firm responsible for building sounding instruments for the NASA-NOAA Suomi National Polar-orbiting Partnership and the Joint Polar Satellite System (JPSS) as well as imagers and sounders for NOAA’s Geostationary Operational Environmental Satellite, or GOES, program. Over the life of the program, NOAA will spend $8 billion on two satellites, sensors, ground systems and operations for GOES-R and $13 billion for JPSS.

“These costs are having a tremendous effect on NOAA’s missions today and probably assuring that no new space-based systems can be acquired,” Webster said.

To save money, NOAA should examine different procurement models, such as acquiring sensors under fixed-price contracts or modifying existing instruments to meet its requirements, Webster said.

Lawmakers also questioned Kicza about the projected gap in NOAA’s polar satellite observation between the conclusion of the Suomi mission and the start of the JPSS observation program. The Suomi satellite launched in October 2011 was designed to operate for five years. The satellite intended to replace it, JPSS-1, is scheduled to launch in early 2017. If JPSS-1 launches on time and Suomi does not operate any longer than anticipated, there will only be a short time when NOAA will not have one of the two spacecraft on-orbit.

However, the agency will need additional time to calibrate the instruments on JPSS with the instruments on Suomi. “Depending on the complexity of the instruments, it takes a different amount of time to fully calibrate them,” Kicza said. “Some instruments can be calibrated within six months, other instruments may take 12 months or longer to calibrate.”

While NOAA officials are concerned that they may experience a gap in their ability to monitor climate and weather conditions, the agency will continue to obtain data from the U.S. Defense Department and Europe’s Meteorological Satellite Organization, Eumetsat. Traditionally, the Defense Department’s polar orbiting satellites cross the equator in the early morning. Eumetsat spacecraft cross in midmorning and NOAA satellites traverse the equator in the afternoon.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...