Here
I discuss the atmospheric circulations on the giant planets in our
solar system
-- Jupiter, Saturn, Uranus, and Neptune -- as well as on some of the
200-odd
giant planets discovered around other stars. The atmospheric
circulations
of our local giant planets are characterized by banded cloud patterns,
numerous
east-west jet streams, and stable vortices at the cloud level.
The
question of what causes these features has remained a puzzle since
high-resolution
spacecraft images of these planets were returned in the 1970s and 1980s. A probable hypothesis is that turbulence
injected into the cloud layer reorganizes into zonal jets and large
vortices. However, existing models have been insufficient to test
the
hypothesis. Here, I describe basic dynamical ideas and numerical
simulations to investigate whether this process can produce
Jupiter-like jets,
and, if so, whether such jets penetrate deeply into the interior or
remain
confined to the forcing layer. The simulations show development of
vortices and
jets that resemble the giant planets in broad outline. But the
details --
such as whether jets dominate over vortices, whether the jets penetrate
deeply
into the interior or remain confined to the forcing level, and whether
the jet
pattern (if any) resembles Jupiter and Saturn -- depends on the type of
forcing, the vertical temperature structure, and other parameters. I then extend these ideas to extrasolar
planets, focusing on those planets orbiting very close to their stars
-- the
so-called "hot Jupiters." These planets are intensely heated on their
daysides and are expected to have a vigorous circulation that shapes
the
day-night temperature difference, infrared lightcurve, spectra, albedo,
and
atmospheric composition. Recent observations place constraints on
the
wind speeds, day-night temperature difference, and albedos of several
hot
Jupiters. I will describe theoretical ideas and numerical
simulations of
the atmospheric circulation of these planets with the goal of
interpreting
these and future observations of these planets.