We study the atmospheric structure in response to the propagation of gravity waves under nonisothermal (nonzero vertical temperature gradient), wind-shear (nonzero vertical zonal/meridional wind speed gradients), and dissipative (nonzero molecular viscosity and thermal conduction) conditions. As an alternative to the “complex wave-frequency” model proposed by Vadas and Fritts, we employ the tra...

[1] We examine the upstream meridional deflection flows of interplanetary coronal mass ejections (ICMEs) in an effort to investigate their cross-sectional shape and the magnetic field orientation in their sheath regions. Eight out of 11 magnetic clouds (MCs) near solar minimum identified for the curvature study are concave outward as indicated by the elevation angle of the MC normal with respec...

A zonal-average model of the upper branch of the meridional overturning circulation of the southern ocean is constructed and used to discuss the processes – wind, buoyancy, eddy forcing and boundary conditions – that control its strength and sense of circulation. The geometry of the thermocline ‘wedge’, set by the mapping between the vertical spacing of buoyancy surfaces (the stratification) on...

As in the midlatitude atmosphere, midocean eddies are primarily generated by baroclinically unstable mean currents. In contrast to the atmosphere, however, oceanic currents are significantly nonzonal. Even weak nonzonal currents are linearly unstable since does not suppress growing meridional waves. Theories for the nonlinear equilibration of baroclinic instability, and hence theories for the a...

Ozone performs a key role in the middle atmosphere and its monitoring is thus necessary. At the Institute of Applied Physics of the University of Bern, Switzerland, we built a new ground-based microwave radiometer, GROMOS-C (GRound based Ozone MOnitoring System for Campaigns). It has a compact design and can be operated remotely with very little maintenance requirements, being therefore suitabl...

An exact solution to the barotropic potential vorticity equation is used to examine the properties of barotropic vortices under arbitrary nth-order hyper-diffusivity. Analytical expressions are derived for an eddy’s lifetime, meridional drift, decay in size, and energy, as functions of the Coriolis parameter, order and magnitude of diffusivity, and the eddy’s size, shape and strength. These exp...

The Antarctic circumpolar wave (ACW) is a nominal 4-yr climate signal in the ocean–atmosphere system in the Southern Ocean, propagating eastward at an average speed of 6–8 cm s21, composed of two waves taking approximately 8 years to circle the globe. The ACW is characterized by a persistent phase relationship between warm (cool) sea surface temperature (SST) anomalies and poleward (equatorward...

in this paper the separation of saffron stigma from stamen and petal in a vertical wind tunnel has been evaluated. a wind tunnel with adjustable speed of 0.1 m s-1 intervals has been developed and used for the experiments. floating velocities of flower components (petal, stigma and stamen) were measured at one, eight, 38 and 60 hours after harvesting. subsequently, the separation was tested by ...

At present, the assimilation of u and v wind vector components calculated from wind speed (SP) and wind direction (DIR) observations (obs) is used as the only scheme for assimilating wind observations into the Weather Research and Forecasting Data Assimilation (WRFDA) three-dimensional variational data assimilation (3D-Var) system. The observational error of the u and v components is assigned b...