This study investigates the effect of stratospheric sudden warmings (SSWs) on planetary wave (PW) activity in the mesosphere–lower thermosphere (MLT). PW activity near 95 km is derived from meteor wind data using a chain of eight SuperDARN radars at high northern latitudes that span longitudes from 150W to 25 E and latitudes from 51 to 66 N. Zonal wave number 1 and 2 components were extracted f...

1 The transport of the Antarctic Circumpolar Current (ACC) varies strongly across the cou2 pled GCMs (general circulation models) used for the IPCC AR4. This note shows that a 3 large fraction of this across-model variance can be explained by relating it to the param4 eterization of eddy-induced transports. In the majority of models this parameterization is 5 based on the study by Gent and McWi...

1 The transport of the Antarctic Circumpolar Current (ACC) varies strongly across the cou2 pled GCMs (general circulation models) used for the IPCC AR4. This note shows that a 3 large fraction of this across-model variance can be explained by relating it to the param4 eterization of eddy-induced transports. In the majority of models this parameterization is 5 based on the study by Gent and McWi...

The dynamics of equatorial currents are considered in the light of the wind and current measurements at Gan (0.5 S, 73E) reported by KNOX (Deep-Sea Research, 23, 211 221, 1976). For westerly and meridional winds the response of equatorial currents is predominantly local and rapid. It follows that the current reversals observed at Gan are most likely due to changes in the local winds and not to ...

The annular mode simulated by an atmospheric general circulation model with a zonally symmetric lower boundary is investigated. The annular mode, defined as the leading empirical orthogonal function (EOF) of the zonal-mean surface pressure, has a meridional structure consisting of a north–south dipole, similar to observations. The leading EOF of the zonally varying surface pressure has the same...

The leading modes of variability of the extratropical circulation in both hemispheres are characterized by deep, zonally symmetric or ‘‘annular’’ structures, with geopotential height perturbations of opposing signs in the polar cap region and in the surrounding zonal ring centered near 458 latitude. The structure and dynamics of the Southern Hemisphere (SH) annular mode have been extensively do...

We provide evidence that midlatitude postsunrise traveling ionospheric disturbances (TIDs) are comprised of electrified waves with an eastward propagation component. The post-sunrise gravity wave (GW) wind-induced dynamo action effectively generated periodic meridional polarization electric fields (PEFs), facilitating TID zonal in a similar fashion as GW-driven neutral perturbations. A combinat...

A crystalline triply bridged molecular gyroscope has been prepared and analyzed by single-crystal X-ray diffraction. A convergent synthetic strategy was developed to control the direction of the three bridges, from the preferred two zonal and one meridional arrangement of a one-step cylclization process to the directed three meridional bridges achieved by a north-south desymmetrization.

A simple technique to infer the missing momentum forcing in a general circulation model is developed and evaluated. The response of the large-scale dynamic equations to an external momentum forcing presents a nonlocal response in the zonal and meridional wind. On the other hand, the response to the external momentum forcing in the potential vorticity (PV) is a local growing geostrophic mode, so...