Arnold Schwarzenegger Governor AIRCRAFT MEASUREMENTS OF THE IMPACTS OF POLLUTION AEROSOLS ON CLOUDS AND PRECIPITATION OVER THE SIERRA NEVADA

DISCLAIMER This report was prepared as the result of work sponsored by the California Energy Commission. It does not necessarily represent the views of the Energy Commission, its employees or the State of California. The Energy Commission, the State of California, its employees, contractors and subcontractors make no warrant, express or implied, and assume no legal liability for the information in this report; nor does any party represent that the uses of this information will not infringe upon privately owned rights. This report has not been approved or disapproved by the California Energy Commission nor has the California Energy Commission passed upon the accuracy or adequacy of the information in this report. Acknowledgments The authors gratefully acknowledge the major contributions that the pilots made to the success of the Suppression of Precipitation (SUPRECIP) field effort. Dr. David Prentice piloted the Cheyenne II cloud physics aircraft during SUPRECIP‐1, and Mr. Gary Walker, Manager of the Seeding Operations and Atmospheric Research (SOAR) program of the Sandyland Underground Water Conservation District, piloted this aircraft in SUPRECIP‐2. Mr. Kevin McLaughlin piloted the Cessna 340 aerosol aircraft. The authors also acknowledge Dr. Don Collins and Ms. Crystal Reed of Texas A&M University for their support with the differential mobility analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) system and Ing. Grazio Axisa for maintaining the aircraft instruments in SUPRECIP‐2. ii iii Preface The Public Interest Energy Research (PIER) Program supports public interest energy research and development that will help improve the quality of life in California by bringing environmentally safe, affordable, and reliable energy services and products to the marketplace. The PIER Program, managed by the California Energy Commission (Energy Commission), conducts public interest research, development, and demonstration (RD&D) projects to benefit California's electricity and natural gas ratepayers. The PIER Program strives to conduct the most promising public interest energy research by partnering with RD&D entities, including individuals, businesses, utilities, and public or private research institutions. PIER funding efforts are focused on the following RD&D program areas: complemented by efforts at other research institutions. Priority research areas defined in PIER's five‐year Climate Change Research Plan are: monitoring, analysis, and modeling of climate; analysis of options to reduce greenhouse gas emissions; assessment of physical impacts and of adaptation strategies; and analysis of the economic consequences of both climate change impacts and the efforts designed to reduce emissions. The California Climate Change Center Report Series details ongoing center‐sponsored research. As …