In a simulation of seasonal cycles with an idealized general circulation model without a hydrologic cycle and with zonally symmetric boundary conditions, the Hadley cells undergo transitions between two regimes distinguishable according to whether large-scale eddy momentum fluxes strongly or weakly influence the strength of a cell. The center of the summer and equinox Hadley cell lies in a lati...

NASA’s Juno spacecraft will make microwave and gravity measurements of Jupiter. These can reveal information about the composition of Jupiter’s atmosphere and about the temperature and density structure below the visible clouds, which is in balance with the structure of the zonal winds. Here we show that there exist strong physical constraints on the structure of the off-equatorial deep zonal w...

In this study, long term observations of medium frequency (MF) radar at Langfang site (39.4°N, 116.7°E) from 2009 to 2020 have been used analyze the dependence 11-year solar cycle on horizontal winds in local mesosphere and lower thermosphere (MLT). The results show that zonal wind is positively correlated with activity during spring 80–84 km, summer 80–82 km; meridional 84–88 km 84–90 km. cont...

[1] On the basis of Colorado State University (CSU) Na lidar observations over full diurnal cycles from May 2002 to April 2006, a harmonic analysis was performed to extract semidiurnal perturbations in mesopause region temperature and zonal and meridional winds over Fort Collins, Colorado (40.6 N, 105.1 W). The observed monthly results are in good agreement with MF radar tidal climatology for U...

A dry primitive equation model is used to explain how the quasi-biennial oscillation (QBO) of the tropical stratosphere can influence the troposphere, even in the absence of tropical convection anomalies and a variable stratospheric polar vortex. QBO momentum anomalies induce a meridional circulation to maintain thermal wind balance. This circulation includes zonal wind anomalies that extend fr...

A simplified model of the moist axisymmetric Hadley circulation is examined in the asymptotic limit in which surface drag is strong and the meridional wind is weak compared to the zonal wind. Our model consists of the quasi-equilibrium tropical circulation model (QTCM) equations on an axisymmetric aquaplanet equatorial beta-plane. This model includes two vertical momentum modes, one baroclinic ...

A medium frequency spaced-antenna radar has been operating at Rothera station, Antarctica (67 S, 68 W) for two periods, between 1997–1998 and since 2002, measuring winds in the mesosphere and lower thermosphere. In this paper monthly mean winds are derived and presented along with three years of radiosonde balloon data for comparison with the HWM-93 model atmosphere and other high latitude sout...

The quasi-geostrophic global stratospheric model at MIT developed by is used to study the zonal and time-averaged transport of potential temperature and ozone by the planetary zonal wavenumbers 1-6. Several types of covariances between the winds, geopotential, and the tracers are calculated in order to evaluate the directions and strength of the fluxes and the winds causing the fluxes. The eddy...

This SI Appendix is formed by three sections. Section 1 contains a brief discussion of the derivations of the dynamical model and its low-order meridional truncation. The details of boundary conditions, numerical solvers as well as a list of the parameter values are also included. The mathematical formula of the anomalous Walker circulation is shown at the end of this section. Section 2 involve...