Abstract: High-resolution simulations of a polar vortex disturbed by quasi-topographic forcing are performed using the method of ?contour surgery?, a numerical method for inviscid flows wherein arbitrarily steep vorticity gradients ...

Abstract: The characteristics of the poleward advection of upper-tropospheric air are investigated using meteorological analyses and idealized numerical models. Isentropic deformations of the tropopause during Northern Hemisphere ...

Abstract: 30-yr climatology of Rossby wave breaking (RWB) on the Southern Hemisphere (SH) tropopause is formed using 30 yr of reanalyses. Composite analysis of potential vorticity and meridional fluxes of wave activity show that RWB ...

Abstract: Heterogeneities in the land surface exist on a wide range of spatial scales and make the coupling between the land surface and the overlying boundary layer complex. This study investigates the vertical extent to which the ...

Abstract: We present a trajectory technique, contour advection with surgery (CAS), for tracing the evolution of material contours in a specified (including observed) evolving flow. CAS uses the algorithms developed by Dritschel for ...

Abstract: The three-dimensional structure of wave propagation and breaking on the edge of polar vortices is examined using a multilayer quasigeostrophic model, with piecewise constant potential vorticity (PV) in each layer. The ...

Abstract: dry general circulation model is used to investigate the connections between Rossby wave breaking and the latitude of the midlatitude tropospheric eddy-driven jet. An ensemble of experiments is constructed in which the jet ...

Abstract: It has recently been shown that extreme stratospheric events (ESEs) are followed by surface weather anomalies (for up to 60 days), suggesting that stratospheric variability might be used to extend weather prediction beyond ...

Abstract: Heterogeneities in the land surface on scales smaller than the typical general circulation model (GCM) grid size can have a profound influence on the grid-scale mean climate. There exists observational and modeling evidence ...

Abstract: The propagation of a range of tracer signals in a simple model of the deep western boundary current is examined. Analytical expressions are derived in certain limits for the transit-time distributions and the propagation ...