PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
Contact: Mary Hardin
FOR IMMEADIATE RELEASEDecember 22, 1997
TWO JPL SCIENTISTS ELECTED FELLOWS OF THE AMERICAN GEOPHYSICAL
JPL scientists Dr. David Halpern and William L. Sjogren have
been elected Fellows to the American Geophysical Union (AGU), an
international scientific society dedicated to advancing the
understanding of Earth and our Solar System. The AGU has a
membership of approximately 36,000 scientists in 130 countries.
Halpern was recognized for his pioneering work on El Nino
and his research of equatorial and coastal currents and for
scientific and organizational leadership in programs to study
interactions between the ocean and atmosphere.
Halpern joined JPL in 1986 and is a senior research
scientist and manager of JPL's Climate Variability Program. He
has also managed the NASA Ocean Data System based at JPL and has
published more than 275 scientific articles. He is now using
data from JPL instruments to study monsoons and middle-latitude
influences of El Nino, including the strange occurrence of three
El Nino episodes from 1991 to 1995.
He received bachelor's degrees in geology and physics with
honors from McGill University in Montreal and a doctorate in
physical oceanography from the Massachusetts Institute of
Technology, then pursued postdoctoral research at the National
Institute of Oceanography in England.
Halpern has also been named a Fellow of the American
Meteorological Society and of the California Academy of Sciences,
as well as being awarded a U.S. Department of Commerce Silver
Medal in 1981 for technological developments that created the
present-day El Nino Buoy Watch and eight Scientific Achievement
Awards from the National Oceanic and Atmospheric Administration.
He was a visiting professor at the California Institute of
Technology, Pasadena, CA, and is currently an adjunct professor
at the University of California, Los Angeles, where he teaches
Halpern and his wife, Tema, live in La Canada, California.
They have two children.
Sjogren was honored by the AGU for his pioneering work
studying planetary gravity fields using radio data from orbiting
Sjogren joined JPL in 1962 and is a senior research
scientist in the navigation and flight mechanics section. He has
worked on the Ranger, Surveyor, Lunar Orbiter and Mariner
planetary missions. He was principal investigator for gravity
field determination on the Apollo 12, 14, 15, 16, 17 missions;
Viking I and II; the Pioneer Venus Orbiter; Magellan and NASA's
Mars Global Surveyor.
He was a co-discoverer of the Lunar Mascons, the very large
unexpected gravity highs located in the circular maria basins.
The discovery placed stringent constraints on the internal
structure of the moon. He is the recipient of two NASA
Scientific Achievement Awards and has published more than 130
scientific articles. He is presently estimating the gravity
fields of the four Galilean satellites of Jupiter.
He received a bachelor's degree in civil engineering from
the University of Miami (magna cum laude) and a master's degree
in applied math from Northwestern University.
Sjogren lives in La Canada with his wife, Mary Alice. They
have four children and six grandchildren.
JPL is a division of the California Institute of
Technology, Pasadena, CA.