  The characterization of exoplanetary atmospheres has come of age in the last
decade, as astronomical techniques now allow for albedos, chemical abundances,
temperature profiles and maps, rotation periods and even wind speeds to be
measured. Atmospheric dynamics sets the background state of density,
temperature and velocity that determines or influences the spectral and
temporal appearance of an exoplanetary atmosphere. Hot exoplanets are most
amenable to these characterization techniques; in the present review, we focus
on highly-irradiated, large exoplanets (the "hot Jupiters"), as astronomical
data begin to confront theoretical questions. We summarize the basic
atmospheric quantities inferred from the astronomical observations. We review
the state of the art by addressing a series of current questions and look
towards the future by considering a separate set of exploratory questions.
Attaining the next level of understanding will require a concerted effort of
constructing multi-faceted, multi-wavelength datasets for benchmark objects.
Understanding clouds presents a formidable obstacle, as they introduce
degeneracies into the interpretation of spectra, yet their properties and
existence are directly influenced by atmospheric dynamics. Confronting general
circulation models with these multi-faceted, multi-wavelength datasets will
help us understand these and other degeneracies. The coming decade will witness
a decisive confrontation of theory and simulation by the next generation of
astronomical data.
