Richard Frank “Dick” Donnelly, ionospheric and solar‐terrestrial physicist at the National Oceanic and Atmospheric Administration’s Space Environment Center (now Space Weather Prediction Center) in Boulder, Colorado, died of melanoma on 19 August 2009. Born in Sioux Falls, South Dakota, on 26 March 1937, to Richard James Donnelly and Doris Lynum Donnelly, he graduated from Washington High School and the South Dakota School of Mines and Technology and received his M.S. and Ph.D. degrees in electrical engineering from the University of Illinois. On June 18, 1966, he married Elizabeth Ann Lindahl in Granville, Ohio. They had two children, Richard Scot and Lora Elizabeth. When Lora was three weeks old, the family moved to Honolulu, where Donnelly was on the visiting faculty at the University of Hawaii.
Donnelly was a leading NOAA scientist on a number of projects involving analysis of space-based measurements of solar flares and their effect on the ionosphere, solar ultraviolet and X-ray emission, and solar spectral-line profiles. He was also a prominent figure in the development and organization of the Solar Electromagnetic Radiation Study for Cycle 22 (SOLERS22). He helped develop some of the major indices used by the space weather community, including the GOES 0.1-0.8 nm background index, the NOAA Mg II core-to-wing ratio index, and the SERF2 solar flux model, which was the precursor to SOLAR2000 and later SIP.
Among Donnelly’s papers on the ionosphere are “The Solar Flare Radiations Responsible for Sudden Frequency Deviations [of the ionosphere].” Journal of Geophysical Research (JGR) 72 (1967): 5247-5256; “The Equatorial Total Electron Content and Shape Factor.” JGR 84 (1979): 7359-7364. He reported on scanning spectrometer measurements from the Orbiting Solar Observatory (OSO3) in the paper “Extreme Ultraviolet Spectrum of the Solar Flare of 2114 UT March 27, 1967.” Solar Physics 31 (1973): 411-. Donnelly wrote a number of papers on solar variability: “Differences in the Temporal Variations of Solar UV Radio Flux, Sunspot Number, and Ca-K Plage Data Caused by Solar Rotation and Active Region Evolution.” JGR 88 (1983): 9883-9888; “Temporal Variations of Solar EUV, UV, and 10,833-Angstrom Radiations.” JGR 91 (1986): 5567-5578. Later papers include “Thirteen-Day Periodicity and the Center-to-Limb Dependence of UV, EUV, and X-ray Emission of Solar Activity.” Solar Physics 130 (1990): 369-; “The Solar Ca II K Index and the Mg II Core-to-Wing Ratio.” Solar Physics 152 (1994): 69-.
With the help of friends, Donnelly built a cabin in the mountains west of Boulder, a region he frequently hiked and took inspiration from. He enjoyed his work as much as his relaxation time, telling a colleague, “Life is great, NOAA pays me for doing my hobby.”
Photo: Space Environment Technologies