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The U.S. Air Force established a Geophysics Directorate at the end of World War II to conduct research in meteorology and geophysics. Over its 50-year history, its scientific programs have broadened to include atmospheric, optical, and space studies.
by Ruth P. Liebowitz, Phillips Laboratory/Geophysics Directorate, Hanscom Air Force Base, Mass.
The U.S. Air Forces' interest in sponsoring geophysical research was initially sparked in the 1930s by the hope that improved weather forecasting would augment the Air Force's flying operations. During World War II, the Allies mounted major forecasting efforts for the 1942 landings in North Africa and the 1944 invasion of Normandy. An increased awareness of other atmospheric effects also grew out of wartime operations. Difficulties with high-frequency radio communications were linked to solar activity. Pilots flying on bombing raids across the Pacific encountered unexpected winds at high altitudes, while radar was sometimes "spooked" by atmospheric effects such as refraction, which lead to false warnings of air attacks.
Toward the end of World War II, the American military recognized the impact of organized science on warfare, particularly through the development of radar and the atomic bomb. Also impressive was the progress the Germans had made toward guided missiles and supersonic flight. These advancements led the military to consider long-term research and development as essential to military preparedness for future conflicts. Weather and the operating environment for military systems were folded in along with obvious areas of weapons research such as aerodynamics and jet propulsion as areas to be supported. A pamphlet written for the Department of Defense in the late 1940s by a well-known climatologist surveyed the impact of the environment on warfare in recent history. It discussed how all the major subfields in the geophysical sciences from geology and hydrology to terrestrial magnetism and electricity could contribute to military capability.
In the immediate postwar period, the U.S. military performed an important "seeding" function for the geophysical sciences. The Department of Defense concluded in 1948 that not enough geophysicists were being trained to meet military and civilian needs and that funding should be allocated to universities to address this deficiency. In the existing sub-fields of geophysics, military funding expanded university faculties and programs, supported graduate students, and provided some with jobs. The navy put considerable funding into oceanography, while the air force focused on meteorology. All three services helped to develop the newer field of upper atmospheric studies.
There has been considerable continuity in the broad program areas supported by the air force over the years. The Geophysics Directorate set up an initial group of programs in the late 1940s. They covered theoretical and applied research in meteorology, upper atmosphere and solar studies, and research on the propagation of electromagnetic, seismic, and acoustic waves. In the late 1950s, the Directorate added programs in space physics and optical/infrared studies, followed shortly by geodesy and gravity. Supporting these research areas was an engineering program thatdeveloped experimental meteorological equipment, sounding rockets and balloons, and instruments for satellites.
The research programs undertaken by the directorate over the postwar period have evolved considerably in keeping with scientific advances, new technology, and changing military requirements. The Army Air Forces' goal immediately after the war to become an all-weather-flying force made for a strong focus on meteorological research. Directorate meteorologists investigated the jet stream and hurricanes, and they participated in trials of cloud seeding to test their feasibility for military and civilian uses.
Wartime concerns about radio communications also led to expanded studies of the ionosphere. Appreciation of the Sun as the controlling source of energy for the upper atmosphere and ionosphere boosted funding for solar research. In the late 1940s the Geophysics Directorate built a new solar coronagraphic observatory at Sacramento Peak, N. Mex., now a section of the National Solar Observatory. A long-term basic research program in solar physics and solar-terrestrial effects was initiated at Sac Peak in 1952.
The possibility of a future war fought in polar regions spurred study of the Arctic terrain and environment in the 1950s. GRD's second chief, Joseph Fletcher, won fame by manning a research station on a floating ice island that was later named after him. Polar studies continued during the International Geophysical Year, 1957 - 1958.
The late 1950s marked the beginning of a new era for geophysics. Satellites and manned spacecraft provided exciting possibilities for exploring solar-terrestrial physics. The civilian and military space community were also concerned about satellite performance, satellite-ground communication links and, above all, astronaut safety. Programs in space physics emerged at the Geophysics Directorate. Some lunar and planetary programs were also begun, and the directorate helped to develop the new satellite meteorology.
The need for accurate targeting of the new ballistic missiles in the 1960s led to a new research program in geodesy, gravity, and lunar laser ranging. When the 1963 Nuclear Test Ban Treaty outlawed all but underground nuclear tests, the pioneering studies of seismic propagation took on increased importance. The directorate's program is now focused on providing the enhanced seismic capability that will be required to monitor a future Comprehensive Test Ban Treaty (CTBT).
In the late 1970s when the organization became the Air Force Geophysics Laboratory, it began to create models and algorithms for environmental forecasting. AFGL meteorologists had demonstrated how Doppler radar could be used to predict tornados. Building on this work, they began developing algorithms to detect weather-related hazards such as tornadoes, hail, gust fronts, and windshear.
The organization was also a key player in the development of "space weather" forecasting in the United States starting in the 1970s. Space weather forecasting is being developed to avoid hazards such as radiation doses to astronauts and microelectronics in space, degradation of satellite communications, displacement of satellite orbits, and damage to power grids and pipelines on Earth. In 1991, the creation of a third radiation belt was recorded by the directorate following the major geomagnetic storm of March 1991.
Over its 50 year history, the directorate has contributed to the growth of the geophysical sciences in the United States in a number of ways. It has conducted in-house research and development programs, funded university research, created new research facilities, sponsored conferences in areas at the frontiers of the geophysical disciplines, underwritten the publication of data and reference works, and developed engineering expertise. The Geophysics Directorate—known today as the Air Force Geophysics Laboratory—looks forward to its next 50 years.
Source: Eos, Vol. 76, September 19, 1995, p. 371.
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