As a Ph.D. student in the 1960s, University Distinguished Professor Emeritus Tom Vonder Haar obtained the first measurements of Earth’s radiation budget, the balance of incoming energy from the sun and outgoing energy from the Earth. In the 1980s, he led NASA’s Earth Radiation Budget Experiment that launched three satellites to begin continuously collecting data on Earth’s radiation budget. Now he is senior adviser on NASA’s latest project that will extend the 40-year continuous record and provide clues about our climate.
This new, nearly $130-million project called Libera not only will continue an important record of the solar radiation entering the atmosphere and the amount absorbed, reflected and emitted by Earth, it will improve the record’s accuracy and give us more details about this balance. We know from past observations that extreme events, such as major volcanic eruptions and El Niño, have disrupted this energy exchange. The more specific wavelength ranges gathered by Libera will help scientists better understand changes to Earth’s climate system, including whether the planet is getting brighter or darker, and heating up or cooling down.
“The instruments are much, much better now, in all respects,” said Vonder Haar. “They can measure things with much higher accuracy than we could back in those days.”
When Vonder Haar and Verner Suomi, his adviser at the University of Wisconsin, started taking measurements in the ’60s, satellites didn’t last very long. This caused gaps in the data until NASA’s Earth Radiation Budget Experiment (ERBE), with Vonder Haar as principal investigator, began continuous monitoring.
Without a continuous record, it would be difficult to assess climate trends. Libera aims to make that possible, picking up where the current monitoring system, CERES, leaves off. The technology of CERES, or Clouds and the Earth’s Radiant Energy System, is 10 to 15 years old.
Libera’s new and improved instruments and calibration methods were developed by Principal Investigator Peter Pilewskie and his colleagues at the University of Colorado Laboratory for Atmospheric and Space Physics. LASP leads the instrument development with key contributions from Ball Aerospace, NIST Boulder Laboratories and ground calibration support from Utah State University’s Space Dynamics Lab.
Vonder Haar was thrilled to be invited to share his extensive experience and knowledge as senior adviser, extending his pioneering work on the subject.
“[Libera] continues the relationship that CSU has had with colleagues in Boulder, including Ball Aerospace, which goes back to when I worked with them in the late ’70s and ’80s on ERBE,” Vonder Haar said. “It continues, in a small way, the legacy of Colorado, Ball Aerospace, CU and CSU.”
Other CSU contributors on the 25-person, multinational team are University Distinguished Professor Emeritus Graeme Stephens, now at the Jet Propulsion Laboratory, and postdoctoral fellow Maria Hakuba. Libera was selected from four competitive proposals and is scheduled to launch by December 2027.