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Vol. Eos, 87, No. 4, 24 January 2006 over the past two decades, Science, 304, 1299 1301, doi:10.1126/science.1094070. Pall , E., PMonta s-Rodriguez, PR. Goode, S. E. Koonin, . . M.Wild, and S. Casadio (2005),A multi-data comparison of shortwave climate forcing changes, Geophys. Res. Lett., 32, L21702, doi:10.1029/2005GL023847. . Ramanathan,V., R. D. Cess, E. F Harrison, P Minnis, . B. R. Barkstrom, E.Ahmad, and D. Hartmann (1989), Cloud-radiative forcing and climate: Results from the Earth Radiation Budget Experiment, Science, 243, 57. Stanhill, G., and S. Cohen (2001), Global dimming: A review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences,Agric. For. Meteorol., 107, 255. Wielicki, B.A., et al. (2002), Evidence for large decadal variability in the tropical mean radiative energy budget, Science, 295, 841. Wielicki, B.A.,T.Wong, N. Loeb, P Minnins, K. Priestley, . and R. Kandel (2005), Changes in Earth s albedo measured by satellite, Science, 308, 825. Wild, M., H. Gilgen,A. Roesch,A. Ohmura, C. Long, and E. G. Dutton (2005), From dimming to brightening: Trends in solar radiation inferred from surface observations, Science, 308, 847. Author Information Enric Pall , Big Bear Solar Observatory, Big Bear City, Calif.; E-mail: epb@bbso.njit.edu; Philip R. Goode, Big Bear Solar Observatory and W. K. Kellogg Radiation Laboratory, California Institute of Technology (Caltech), Pasadena; Pilar Monta s-Rodriguez, Big Bear Solar Observatory; and Steven. E. Koonin,W.K. Kellogg Radiation Laboratory, Caltech news NASA Terminates Two Earth Observation Missions PAGE 38 Citing a lack of available funds, NASA has ended support for two Earth observation missions: Hydros, which never left the formulation phase, and the Deep Space Climate Observatory (DSCOVR), which was already built and waiting for launch. Richard Anthes, president of the University Corporation for Atmospheric Research, Boulder, Colo., said that these two new cancellations are further evidence that the nation s Earth-observation satellite programs are at risk. Anthes co-chairs a committee of the National Research Council (NRC) of the U.S. National Academies that is conducting a decadal survey of Earth science and applications from space, which should be completed by the end of 2006. In a September 2005 interim report, the committee concluded that the U.S. system of Earth observation satellites was at risk of collapse, in part because of the cancellations or delays of six other missions (see Eos, (86)43, 2005). Hydros was selected as an alternate mission in 2002 in the third round of competition for the Earth System Science Path nder (ESSP) program which funds small- and mediumsized Earth science missions and had a tentative launch date of September 2010.The mission would have used low frequency mapping radar and radiometer instruments to measure soil moisture for use in weather and climate prediction models, in drought mitigation efforts, and for better understanding of the global hydrologic, energy, and carbon cycles. Hydros, unlike other current and planned satellites that use high frequency ranges, would be able to make these measurements under vegetation canopies and would be able to determine if the moisture is frozen, which is important for weather and climate prediction, to according mission principal investigator Dara Entekhabi, of the Massachusetts Institute of Technology, Cambridge. NASA allowed Hydros to enter the formulation phase in 2003, and mission science and engineering teams were working on algorithms and instrument and spacecraft speci cations until they received notice from NASA in December 2005 that the agency would no longer fund the project because it only had funds for the two primary missions, the Orbiting Carbon Observatory and Aquarius. NASA had spent about $5 million total on Hydros, according to Entekhabi. Anthes said the termination of Hydros means that [ESSP] is inde nitely delayed at best and, at worst, it is dead. The 2005 NRC report had highlighted ESSP as a critical need for the nation s Earth observation programs. Jack Kaye, director of the research and analysis program in NASA s Earth-Sun System Division, said that NASA plans to have another round of ESSP competition,although no date has been announced. Hydros investigators can re-propose the mission in the next round of ESSP competition, Kaye said. A Satellite Grounded DSCOVR has a longer history: In March 1998, then U.S.Vice President Al Gore proposed a mission named Triana to provide real-time images of the Earth from the Lagrange-1 (L-1) point, where the gravitational forces of the Earth and Sun are equal. Panned by some Republicans as Goresat , the mission was reborn as DSCOVR following a 2000 NRC report that noted its scienti c importance.The satellite was originally scheduled for launch via the space shuttle in 2001 but was delayed and then put on inde nite hold following the loss of Columbia in 2003. The satellite would provide a continuous synoptic view of the Earth and facilitate climate science by measuring energy re ected (albedo) over an entire hemisphere. No other satellites can currently obtain these measurements, which are needed to determine the effect of albedo on climate, according to DSCOVR principal investigator Francisco Valero, of the University of California San Diego, Scripps Institution of Oceanography. In addition, DSCOVR would be able to monitor solar activity and act as an early warning system for solar storms that could damage communications systems on Earth, he said. NASA has already spent $100-120 million on DSCOVR, and Valero estimated that the launch and operations, including adapting it to a new launch vehicle, would cost another $60 120 million. However, he noted that the costs could be shared between NASA and the U.S. National Oceanic and Atmospheric Administration, which has expressed interest in the satellite s solar monitoring capabilities for use in disaster prevention and has commissioned a study of the agency s possible participation. Kaye said that in the current budget environment that has left NASA with limited funds for Earth science, it did not make sense for NASA to continue supporting DSCOVR in the indeterminate state it was left in following the loss of its launch vehicle. Nobody likes to start something and not be able to nish it, he said. But at some point, you have to manage with the budget you have and make priority-based decisions. However,Valero said that NASA has to decide to choose projects that are not cancelled before they y because it is a waste of money and the time and effort of the scientists involved. SARAH ZIELINSKI, Staff Writer

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