@comment{{This file has been generated by bib2bib 1.97}}
@comment{{Command line: bib2bib --quiet -c year=2011 -c $type="ARTICLE" -oc pub2011.txt -ob pub2011.bib}}
  author = {{Cottereau}, L. and {Rambaux}, N. and {Lebonnois}, S. and {Souchay}, J.
  title = {{The various contributions in Venus rotation rate and LOD}},
  journal = {\aap},
  archiveprefix = {arXiv},
  eprint = {1104.4009},
  primaryclass = {astro-ph.EP},
  keywords = {celestial mechanics, planets and satellites: individual: Venus},
  year = 2011,
  volume = 531,
  eid = {A45},
  pages = {A45},
  abstract = {{Context. Thanks to the Venus Express Mission, new data on the properties
of Venus could be obtained, in particular concerning its rotation. 
Aims: In view of these upcoming results, the purpose of this paper is to determine and compare the major physical processes influencing the rotation of Venus and, more particularly, the angular rotation rate.
Methods: Applying models already used for Earth, the effect of the triaxiality of a rigid Venus on its period of rotation are computed. Then the variations of Venus rotation caused by the elasticity, the atmosphere, and the core of the planet are evaluated.
Results: Although the largest irregularities in the rotation rate of the Earth on short time scales are caused by its atmosphere and elastic deformations, we show that the irregularities for Venus are dominated by the tidal torque exerted by the Sun on its solid body. Indeed, as Venus has a slow rotation, these effects have a large amplitude of two minutes of time (mn). These variations in the rotation rate are greater than the one induced by atmospheric wind variations that can reach 25-50 s of time (s), depending on the simulation used. The variations due to the core effects that vary with its size between 3 and 20 s are smaller. Compared to these effects, the influence of the elastic deformation caused by the zonal tidal potential is negligible.
Conclusions: As the variations in the rotation of Venus reported here are close to 3 mn peak to peak, they should influence past, present, and future observations, thereby providing further constraints on the planet's internal structure and atmosphere. }}, doi = {10.1051/0004-6361/201116606}, adsurl = {}, localpdf = {REF/2011A_26A...531A..45C.pdf}, adsnote = {Provided by the SAO/NASA Astrophysics Data System} }
  author = {{Parish}, H.~F. and {Schubert}, G. and {Covey}, C. and {Walterscheid}, R.~L. and 
	{Grossman}, A. and {Lebonnois}, S.},
  title = {{Decadal variations in a Venus general circulation model}},
  journal = {\icarus},
  year = 2011,
  volume = 212,
  pages = {42-65},
  abstract = {{The Community Atmosphere Model (CAM), a 3-dimensional Earth-based
climate model, has been modified to simulate the dynamics of the Venus
atmosphere. The most current finite volume version of CAM is used with
Earth-related processes removed, parameters appropriate for Venus
introduced, and some basic physics approximations adopted. A simplified
Newtonian cooling approximation has been used for the radiation scheme.
We use a high resolution (1{\deg} by 1{\deg} in latitude and longitude) to
take account of small-scale dynamical processes that might be important
on Venus. A Rayleigh friction approach is used at the lower boundary to
represent surface drag, and a similar approach is implemented in the
uppermost few model levels providing a 'sponge layer' to prevent wave
reflection from the upper boundary. The simulations generate
superrotation with wind velocities comparable to those measured in the
Venus atmosphere by probes and around 50-60\% of those measured by cloud
tracking. At cloud heights and above the atmosphere is always
superrotating with mid-latitude zonal jets that wax and wane on an
approximate 10 year cycle. However, below the clouds, the zonal winds
vary periodically on a decadal timescale between superrotation and
subrotation. Both subrotating and superrotating mid-latitude jets are
found in the approximate 40-60 km altitude range. The growth and decay
of the sub-cloud level jets also occur on the decadal timescale. Though
subrotating zonal winds are found below the clouds, the total angular
momentum of the atmosphere is always in the sense of superrotation. The
global relative angular momentum of the atmosphere oscillates with an
amplitude of about 5\% on the approximate 10 year timescale. Symmetric
instability in the near surface equatorial atmosphere might be the
source of the decadal oscillation in the atmospheric state. Analyses of
angular momentum transport show that all the jets are built up by
poleward transport by a meridional circulation while angular momentum is
redistributed to lower latitudes primarily by transient eddies. Possible
changes in the structure of Venus' cloud level mid-latitude jets
measured by Mariner 10, Pioneer Venus, and Venus Express suggest that a
cyclic variation similar to that found in the model might occur in the
real Venus atmosphere, although no subrotating winds below the cloud
level have been observed to date. Venus' atmosphere must be observed
over multi-year timescales and below the clouds if we are to understand
its dynamics.
  doi = {10.1016/j.icarus.2010.11.015},
  adsurl = {},
  localpdf = {REF/2011Icar..212...42P.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}