Peter V. Hobbs Memorial Endowed Lecture in Experimental Meteorology

Bart Geerts

Professor Bart Geerts

February 15, 2018

7:30-8:30, Kane Hall, Room 220

Prof. Bart Geerts

Professor, Department of Atmospheric Science, University of Wyoming

Lecture: "The history of cloud seeding to enhance precipitation, and prospects for the future"


Thank you to everyone who attended! It was great to have you join us.

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Cloud seeding is conducted in most states in the western United States, and in other arid regions around the world, in order to enhance precipitation. The main target is winter storms over mountains. The history of cloud seeding is long, and many cloud physicists, including Peter V. Hobbs, built their early career on researching seeding efficacy in the 1960s-1980s. Federal support for weather modification research ceased about three decades ago, not because of environmental or ethical concerns, but rather because of the difficulty of signal detection in the “noise’ of natural variability. Peter V. Hobbs became one of the most vociferous scientists to show that some published claims of seeding impact were exaggerated, false, or unverifiable. Operational seeding, meanwhile, has continued unabated, especially in dry years. We are now in a far stronger position to study changes in mountain clouds following injection of artificial ice nuclei, by means of both detailed observations using new instruments, and high-performance computing efforts that simulate the flow, cloud, and snowfall over the mountains. Thus the National Science Foundation recently supported some field work to re-examine this issue. We now have definitive proof that cloud seeding can have a modest impact on precipitation, but it remains very difficult to detect and target the “right” clouds.

About the Speaker

Dr. Bart Geerts conducts research into cloud-scale to mesoscale atmospheric processes, mainly using aircraft measurements and radar. Much of his research builds on field campaign observations, starting with the Genesis of Atlantic Lows Experiment (GALE-1986) where he participated as a graduate student. He received his PhD from the University of Washington (Atmospheric Science, 1990, advisor: Peter V. Hobbs), and MS (Irrigation Engineering, 1985) and BS (Physical Geography, 1984) from the University of Louvain in Belgium, his country of origin. He has taught on various campuses in the US as well as in Australia and Europe, and has been a faculty member at another “UW" (in Wyoming) since 2000. Dr. Geerts has chaired the American Meteorological Society (AMS) Radar Meteorology Conference, has served on the UCAR Unidata Committee and on several AMS STAC committees (Mesoscale Processes; Weather Modification; and Radar Meteorology). He has been involved in many field campaigns, mainly using the UW King Air aircraft, studying a variety of weather systems, including shallow cumuli, frontal systems, mesoscale boundary-layer processes, orographic precipitation, and even cloud seeding, for which he received the 2012 National Institutes for Water Resources Program IMPACT Award. 


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Peter Hobbs

Professor Peter V. Hobbs

Hobbs Endowed Lectures

Description of Lectureship

The purpose of the Peter V. Hobbs Memorial Endowed Lectureship in Experimental Meteorology shall be to sponsor open lectures in the field of experimental meteorology. Peter Hobbs felt strongly that the furthering of science must be nurtured through the open exchange of ideas amongst scientists. To that end, he planned to fund an Endowed Lectureship in Experimental Meteorology for the Atmospheric Sciences Department at the University of Washington where he had worked for 42 years.

Peter Hobbs was deeply involved all his working life in the field of experimental meteorology which ranges from the microscale, through the mesoscale, up to the global scale, and includes both the physics and chemistry of the atmosphere. The common threads in this field are the ubiquitous roles played by aerosols, clouds and precipitation in the atmosphere.

The gift to establish this endowed lectureship was made in loving memory of Peter by his wife and three sons.

Husky One Aircraft

The CARG's Convair-580 research
aircraft in Pietersburg, South Africa,
during the SAFARI-2000 Field Project.
Photo: NASA Dryden Flight Research Center

Hobbs Career Information

Professor Peter V. Hobbs was a faculty member of Atmospheric Sciences at the University of Washington from 1963 to 2005. He received his B.Sc. and Ph.D. degrees in Physics from the Imperial College of Science and Technology, University of London, in 1960 and 1963, respectively. Director of the Cloud and Aerosol Research Group at the University of Washington from 1963 to 2005.

Principal research interests were cloud and precipitation physics, mesoscale meteorology, atmospheric chemistry and air pollution.

In addition to his steady stream of discoveries about all aspects of clouds—published in 340 papers—Hobbs advised more than 50 graduate students after arriving at the University of Washington, repopulating the field of atmospheric physics.

None of this would have been possible had Hobbs not had a talent for stringing together the funds for aircraft for 40 years, starting with a WWII vintage bomber previously owned by eccentric billionaire aviator Howard Hughes.

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