16,929 research outputs found
Thermal tides in the Martian middle atmosphere as seen by the Mars Climate Sounder
The first systematic observations of the middle atmosphere of Mars (35–80km) with the Mars Climate Sounder (MCS) show dramatic patterns of diurnal thermal variation, evident in retrievals of temperature and water ice opacity. At the time of writing, the data set of MCS limb retrievals is sufficient for spectral analysis within a limited range of latitudes and seasons. This analysis shows that these thermal variations are almost exclusively associated with a diurnal thermal tide. Using a Martian general circulation model to extend our analysis, we show that the diurnal thermal tide dominates these patterns for all latitudes and all seasons
Spectral Spatial Fluctuations of CMBR: Strategy and Concept of the Experiment
Spectral Spatial Fluctuations (SSF) of the Cosmic Microwave Background
Radiation (CMBR) temperature are considered as a result of an interaction of
primordial atoms and molecules with CMBR in proto-objects moving with peculiar
velocities relative to the CMBR. Expected optimistic values of are
2x10^{-5}--2x10^{-6}^+\Delta ^{-5}$ with 6'-7' angular and 2% frequency resolution. Simulation shows that
SSF may be recognized in the angular power spectrum when S/N in single
frequency CMBR maps is as small as 1.17 or even something less for white noise.
Such an experiment gives us a possibility to set upper limit of SSF in MM band
and prepare future SSF observations.Comment: 26 pages, 6 figure
Planetary Geology: Goals, Future Directions, and Recommendations
Planetary exploration has provided a torrent of discoveries and a recognition that planets are not inert objects. This expanded view has led to the notion of comparative planetology, in which the differences and similarities among planetary objects are assessed. Solar system exploration is undergoing a change from an era of reconnaissance to one of intensive exploration and focused study. Analyses of planetary surfaces are playing a key role in this transition, especially as attention is focused on such exploration goals as returned samples from Mars. To assess how the science of planetary geology can best contribute to the goals of solar system exploration, a workshop was held at Arizona State University in January 1987. The participants discussed previous accomplishments of the planetary geology program, assessed the current studies in planetary geology, and considered the requirements to meet near-term and long-term exploration goals
Irreducible decomposition of Gaussian distributions and the spectrum of black-body radiation
It is shown that the energy of a mode of a classical chaotic field, following
the continuous exponential distribution as a classical random variable, can be
uniquely decomposed into a sum of its fractional part and of its integer part.
The integer part is a discrete random variable (we call it Planck variable)
whose distribution is just the Bose distribution yielding the Planck law of
black-body radiation. The fractional part is the dark part (we call is dark
variable) with a continuous distribution, which is, of course, not observed in
the experiments. It is proved that the Bose distribution is infinitely
divisible, and the irreducible decomposition of it is given. The Planck
variable can be decomposed into an infinite sum of independent binary random
variables representing the binary photons (more accurately photo-molecules or
photo-multiplets) of energies 2^s*h*nu with s=0,1,2... . These binary photons
follow the Fermi statistics. Consequently, the black-body radiation can be
viewed as a mixture of statistically and thermodynamically independent fermion
gases consisting of binary photons. The binary photons give a natural tool for
the dyadic expansion of arbitrary (but not coherent) ordinary photon
excitations. It is shown that the binary photons have wave-particle
fluctuations of fermions. These fluctuations combine to give the wave-particle
fluctuations of the original bosonic photons expressed by the Einstein
fluctuation formula.Comment: 29 page
A study on black-body radiation: classical and binary photons
The present study gives a detailed analysis of the black-body radiation based
on classical random variables. It is shown that the energy of a mode of a
chaotic radiation field (Gauss variable) can be uniquely decomposed into a sum
of a discrete variable (Planck variable having the Planck-Bose distribution)
and a continuous dark variable (with a truncated exponential distribution of
finite support). The Planck variable is decomposed, on one hand, into a sum of
binary variables representing the binary photons of energies 2^s*h*nu with
s=0,1,2,etc. In this way the black-body radiation can be viewed as a mixture of
thermodinamically independent fermion gases. The Planck variable can also be
decomposed into a sum of independent Poisson components representing the
classical photo-molecules of energies m*h*nu with m=1,2,3,etc. These classical
photons have only particle-like fluctuations, on the other hand, the binary
photons have wave-particle fluctuations of fermionic character.Comment: 20 page
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