The General Circulation of the Atmosphere

Abstract

Theories of how Earth's surface climate may change in the future, of how it may have been in the past, and of how it is related to climates of other planets must build upon a theory of the general circulation of the atmosphere. The view of the atmospheric general circulation presented here focuses not on Earth's general circulation as such but on a continuum of idealized circulations with axisymmetric flow statistics. Analyses of observational data for Earth's atmosphere, simulations with idealized general circulation models, and theoretical considerations suggest how characteristics of the tropical Hadley circulation, of the extratropical circulation, and of atmospheric macroturbulence may depend on parameters such as the planet radius and rotation rate and the strength of the differential heating at the surface.

The dynamics of the Snowball Earth Hadley circulation for off-equatorial and seasonally varying insolation

“…Because the cell approximately conserves angular momentum during the transition into the winter regime, the cell responds directly to changes in the thermal driving (Schneider, 2006), and the mean-flow feedback described in Schneider and Bordoni (2008) explains the rapidity of the transition. Directly before the transition, at day 20, the maximum in lowlevel potential temperature and the boundary between the southern and northern cell are at the equator (ϕ θ = 0; ϕ = 0).…”

“…The Snowball Earth atmosphere thus belongs to the class of dry atmospheres, which traditionally have formed the starting point for theories of the large-scale atmospheric circulation. In particular, dry theories have been developed for the Hadley circulation that dominates the zonal-mean circulation of Earth's tropics as well as other planets (Schneider, 2006). studied the dynamics of the Snowball Earth Hadley circulation using a comprehensive atmosphere general circulation model.…”

A rotating annulus driven by localized convective forcing: a new atmosphere-like experiment

“…Diverse theoretical and numerical studies of stratified macroturbulence and equilibration processes have recently explored the possible role of baroclinic instabilities in acting to stabilise their own thermal environment (Zurita-Gotor and Lindzen 2007; Zurita- Vallis 2009, 2010;Schneider and Walker 2006;Schneider 2006). The idea of a feedback between the baroclinic instability and the thermal stratification was originally formulated by Stone (1978).…”

“…Nonlinear wave-wave interactions may play a significant role in determining whether the flow equilibrates to a marginally critical (ξ 1) or supercritical (ξ > 1) state (Vallis 1988;Schneider and Walker 2006;Schneider 2006). Some evidence further suggests that wavewave interactions may become spontaneously suppressed under some conditions (Schneider and Walker 2006;Schneider 2006), leading to marginally critical conditions and the absence of a large-scale turbulent energy cascade, although the detailed structure of the heat sources and sinks may also be important in determining ξ (ZuritaGotor and Vallis 2009Vallis , 2010.…”

“…Some evidence further suggests that wavewave interactions may become spontaneously suppressed under some conditions (Schneider and Walker 2006;Schneider 2006), leading to marginally critical conditions and the absence of a large-scale turbulent energy cascade, although the detailed structure of the heat sources and sinks may also be important in determining ξ (ZuritaGotor and Vallis 2009Vallis , 2010. Schneider (2004) further highlights that the inhibition of nonlinear eddy-eddy interactions offers an explanation for the historic success of linear and weakly nonlinear models of large-scale extratropical dynamics, but also rests on the postulate that the kinematic mixing properties of baroclinic eddies exhibit no essential vertical structure.…”