An idealized atmospheric general circulation model is used to investigate the factors controlling the time scale of intraseasonal (10–100 day) variability of the extratropical atmosphere. Persistence on these time scales is found in patterns of variability that characterize meridional vacillations of the extratropical jet. Depending on the degree of asymmetry in the model forcing, patterns take...

The nonlinear shallow-water equations are used to study the tropical stationary wave response to steady thermal forcing near the equator in earthlike zonally symmetric basic states. A thin (200 m) fluid layer is superimposed over a large (1500 m) zonally symmetric topography distribution that decreases smoothly from the Tropics to the Poles, thus providing the large meridional height gradients ...

We present the first high-resolution (sub-annual) dust particle data set from West Antarctica, developed from the West Antarctic Ice Sheet (WAIS) Divide deep ice core (79.468 S, 112.086 W), and use it to reconstruct changes in atmospheric circulation over the past 2400 years. We find a background dust flux of ∼ 4 mg m−2 year−1 and a mode particle size of 5–8 μm diameter. Through comparing the W...

A VHF atmospheric radar (wind profiler) was used to study tropospheric winds during DAWEX. The profiler, which operated at a frequency of 54.1 MHz, was located at Pirlangimpi (Garden Point) (11.4S, 130.5E) on the Tiwi Islands. Observations were made regularly up to heights near 8 km, with maximum heights occurring when convective activity was strongest. Mean winds observed between October and D...

A 10-yr climatology (1986–95) was performed using ECMWF gridded analyses on isentropic surfaces to identify regions where the lower-tropospheric meridional potential vorticity (PV) gradient changes sign across Africa and Australia during their respective summer seasons. While an African sign reversal has been documented, no similar study has been performed for the Australian region, which also ...

We present a simple semi-empirical model for MJO studies in which it is assumed that the MJO is a moisture mode destabilized by surface flux and cloudradiative feedbacks. The model is one-dimensional in longitude; vertical and meridional structure are entirely implicit. The only prognostic variable is column water vapor, W. The zonal wind field is an instantaneous, diagnostic function of the pr...

A self-contained derivation of the IPESD models [Majda, A.J., Klein, R., 2003. Systematic multi-scale models for the tropics. J. Atmos. Sci. 60, 393–408] governing synoptic and planetary scale tropical flows is provided. This derivation demonstrates the analytic tractability of the model and the effect of zonally and meridionally tilted synoptic scale heating on the forcing of planetary scale f...

The meridional energy transport in the atmosphere and ocean is computed using atmospheric analyses from ECMWF and NMC, and net radiative ux from ERBE. An error analysis of the zonally-averaged total transport shows that errors of 7 Wm 2 in net ux produce transport errors of 0:5PW at the equator, an error of 9% in midlatitudes. Methods for correcting the mass non-conservation in transports deriv...

The wintertime ozone buildup over the Northern Hemisphere (NH) midlatitudes and its connection with the mean meridional circulation in the stratosphere are examined statistically on a monthly basis from October to March (1980–2002). The ozone buildup begins locally in October with positive total ozone tendencies over the North Pacific, which spread eastward and westward in November and finally ...