explanation blue bibcodes open ADS page with paths to full text
Author name code: whitaker
ADS astronomy entries on 2022-09-14
author:"Whitaker, William A."
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Title: Uranus System Exploration Under the New Frontiers Mission Class
(A Novel Perspective)
Authors: Balint, Tibor; Atkinson, David; Babuscia, Alessandra; Baker,
John; Bradford, Case; Elder, Catherine; Conversano, Ryan; Feldman,
Sabrina; Furst, Benjamin; Freeman, Anthony; Garner, Gregory; Goebel,
Dan; Hosseini, Sona; Leonard, Erin; Nordheim, Tom Andre; Petropoulos,
Anastassios; Reh, Kim; Roberts, Scott; Sotin, Christophe; Weiss,
Benjamin; Whitaker, William; Members of JPL's A-Team
2021BAAS...53d.040B Altcode: 2021psad.rept..040B
We outline a framework of New Frontiers concepts for the
scientific exploration of the Uranus System (Uranus, its moons,
rings, magnetosphere) by optimizing the available resources using
SmallSat-inspired instruments and subsystems. We make the case for
including the Uranus System as one of the named NF exploration targets
in the Decadal Survey.
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Title: Distant Seismic Waves from a High-Altitude Source
Authors: Nickel, George H.; Whitaker, William A.
1971GeoJ...26..369N Altcode: 1971GeoJI..26..369N
No abstract at ADS
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Title: The General Circulation of the Solar Atmosphere: A Nonlinear
Mechanism for Countergradient Transport.
Authors: Whitaker, William A.; Nickel, George H.
1968AJS....73R..83W Altcode:
The flow of angular momentum on the surface of the sun is in the
wrong direction if viewed as a diffusion process. This countergradient
transport can be thought of as a flow of energy from small eddies to
larger eddies in wave-number space. We first review the development
of the basic elements of mechanism for turbulent energy flow in this
"wrong" direction. This process depends on the restriction of the
flow to two dimensions, and has been known for over 15 years. We next
trace the development by meteorologists of techniques to calculate
the nonlinear transport of energy between horizontal eddies on a
sphere. Finally, we apply these calculational techniques to the solar
surface, employing arbitrary energy sources at small modes, a model of
turbulent viscous damping, and hundreds of hours of digital computer
calculations. This numerical experiment has been able to build up
random horizontal motions whose long time averages agree with Ward's
averages of sunspot motions. The horizontal instability suggested by
Gilman is found to correspond to a source of small-scale motions which
is in agreement with these averages.
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Title: Heating of the Solar Corona by Gravity Waves.
Authors: Whitaker, William A.
1963ApJ...137..914W Altcode:
A new type of hydrodynamic-wave heating is proposed for the solar
corona. It is shown that internal gravity waves are preferentially
generated by the convection zone and are easily transmitted to the
corona. Acoustic waves with frequency characteristic of the photospheric
granules cannot be transmitted through the reversing layer. The gravity
waves are shown to dissipate by thermal conduction in the corona. A
model is derived giving a 1060 K corona. The sensitivity of this model
to various assumptions is demonstrated. It is stable against small
disturbances, but large instabilities may grow in the presence of a
vertical magnetic field, leading to the formation of coronal streamers
and a hoselike solar wind.
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Title: Project Jason Measurement of Trapped Electrons from a Nuclear
Device by Sounding Rockets
Authors: Allen, Lew, Jr.; Beavers, James L., II; Whitaker, William A.;
Welch, Jasper A., Jr.; Walton, Roddy B.
1959JGR....64..893A Altcode:
Solid-propellant rockets were sent to altitudes of 800 km from three
stations in the eastern United States to observe electrons injected into
the geomagnetic field from a small high-altitude nuclear detonation. The
electron flux was measured by an assembly of Geiger counters. Shortly
after a nuclear detonation above the south Atlantic, a narrow region of
high counting rate was observed. The geometry of the observations is
related to the geomagnetic field. The region consisted of an intense
band about 20 km wide (half-width at half maximum counting rate) and
less intense wings extending at least 700 km north and perhaps 700
km south of the band. Neither position nor width of the band changed
during the observations, which consisted of periodic soundings until 100
hr after the nuclear detonation. The intensity of both the wings and
the band decayed during the measurements as 1/t, which is consistent
with the hypothesis that small-angle scattering is the dominant loss
mechanism. The angular distribution of the radiation was measured,
and the electron flux was observed to be confined very nearly to a
plane perpendicular to the field lines. Spectral measurements show
far fewer electrons above 4 Mev than were expected from the fission
beta spectrum. Betas trapped from the decay of neutrons emitted from
large-yield high-altitude weapon tests in the Pacific were also noted.
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Title: Theory of Geomagnetically Trapped Electrons from an Artificial
Source
Authors: Welch, Jasper A., Jr.; Whitaker, William A.
1959JGR....64..909W Altcode:
A theoretical formulation has been made for the history of an artificial
shell of geomagnetically trapped electrons resulting from low-yielding
nuclear detonations in the exosphere. The formulation assumes a source
distribution and gives the spatial distribution of trapped electrons
along the magnetic field lines, the drift rate around the world, and
the configuration of the resulting shell. Interactions of the shell
with the atmosphere lead to an electron density decaying inversely with
time from injection for times longer than a characteristic lifetime
that is a function of altitude and electron energy. The electron flux
is found to be very nearly confined to a plane perpendicular to the
field direction after several characteristic lifetimes. Scattering by
geomagnetic fluctuations is probably not an important loss mechanism
for the artificial shell, but it may be important for the hard component
of the natural trapped belt. The effect of the geomagnetic anomaly over
the south Atlantic has been described qualitatively. Jason rocket data
and Explorer IV satellite data have been compared with the theoretical
results.