Abstract: The temporal evolution of a regional-scale persistent low-frequency anomaly is examined with data from a 2100-day perpetual January general circulation model. The persistent episodes are determined with an objective analysis ...

Abstract: This investigation examines the dynamical processes that drive the anomalous friction torque associated with intraseasonal length-of-day fluctuations. Diagnostic analyses with National Centers for Environmental Protection?National ...

Abstract: The characteristics of two distinct types of wave breaking in an aquaplanet general circulation model (GCM) are described. A systematic analysis of wave breaking is possible because when a baroclinic wave packet is present, ...

Abstract: Two-layer, quasi-geostrophic weakly nonlinear and low-order spectral models are developed and used to investigate the instability of forced baroclinic Rossby waves to finite-amplitude perturbations. The results are then ...

Abstract: A two-layer quasigeostrophic ?-plane channel model is used to examine the role of the wave-mean flow interaction during the life cycles of baroclinic waves. Two cases are examined: a wide and a narrow jet limit. These two ...

Abstract: A weakly nonlinear baroclinic life cycle is examined with a spherical, multilevel, primitive equation model. The structure of the initial zonal jet is chosen so that the disturbance grows very slowly, that is, linear growth ...

Abstract: The nonlinear evolution of disturbances that emanate from unstable westerly and easterly jet profiles is examined with a two-layer quasi-geostrophic ?-plane channel model. Significant differences arise between the solutions ...

Abstract: A mechanism that drives a zonal jet to meander in the meridional direction is investigated with a two-layer multiwave quasigeostrophic ?-plant channel model. This model isolates the zonal index characteristics of a purely ...

Abstract: Data from a 2025-day Geophysical Fluid Dynamics Laboratory aquaplanet GCM integration are used to examine the temporal evolution of the zonal index, defined as the principal component of the first EOF of the zonally and ...

Abstract: The atmospheric dynamical processes associated with intraseasonal length-of-day (LOD) variability during the austral winter are examined with National Centers for Environmental Prediction?National Center for Atmospheric ...