This study utilizes a decade long (2005-2014) monthly data of Total Column Tropospheric Ozone (TCTO) in Dubson units to evaluate the spatial and temporal trend of LAO over some major cities of West Africa, namely Lagos, Accra, Niamey, Abuja, Bamako, Dakar, Agadez, Conakry, Kano, and Ouagadougou which are either capital cites or major commercial hubs, where the population ranges from 0.09 millio...

The SAMI3/equatorial spread F (Sami3 is also a model of the ionosphere/ESF) code used to simulate growth equatorial plasma bubbles in presence background wind field based on measured winds. winds exhibit well-known “midnight temperature maximum” (MTM) pattern, which an equatorward occurs simultaneously with cessation zonal wind. MTM often preceded by strong (about 100 m/s). circumstance where a...

While stirring and mixing properties in the stratosphere are reasonably well understood in the context of balanced (slow) dynamics, as is evidenced in numerous studies of chaotic advection, the strongly enhanced presence of high-frequency gravity waves in the mesosphere gives rise to a significant unbalanced (fast) component to the flow. The present investigation analyses result from two ideali...

Based on straightforward dynamical considerations, we show how available and upcoming measurements of Saturn’s thermal and gravitational signals can be used to constrain the depth to which its zonal winds penetrate. The dynamical considerations issue from the facts that Saturn has a strong intrinsic heat flux, rotates rapidly, and has negligible atmospheric viscosity. As a result, convective mo...

FIG. 1. EOF of the zonal-mean surface pressure in the CKV model (solid), zonal mean of the nonzonally averaged surface pressure in the CKV model (dashed), and zonal mean of the sector EOF shown in CKV’s Fig. 11a (dotted–dashed). We thank Dr. Robinson for his comments (Robinson 2004). Robinson argues that the results of Cash et al. (2002, hereafter CKV) are not inconsistent with the presence of ...

Argo float data in the tropical Pacific Ocean during January 2003–August 2011 are analyzed to obtain Lagrangian subsurface velocities at their parking depths. Maps of mean zonal velocities at 1000 and 1500 m are presented. At both depths, a series of alternating westward and eastward zonal jets with ameridional scale of 1.58 is seen at the basin scale from 108S to 108N. These alternating jets, ...

The variability of the zonal-mean zonal wind in the Southern Hemisphere is studied using EOF analysis and momentum budget diagnostics of NCEP Reanalysis data (1978-1997). The leading EOF of the zonal-mean zonal wind is well separated from the remaining EOF’s and represents the north/south movement of the mid-latitude jet. Analysis of the momentum budget shows that a positive feedback between th...

We describe a new phenomenon of zonal wind generation by tidal forcing. Following a recent theoretical and numerical analysis [A. Tilgner, Phys. Rev. Lett. 99, 194501 (2007)], we present the first experimental evidence that the nonlinear self-interaction of a tidally forced inertial mode can drive an intense axisymmetric flow in a rotating deformed sphere. Systematic measurements of zonal flows...

A tree-ring chronology network recently developed from the subantarctic forests provides an opportunity to study long-term climatic variability at higher latitudes in the South American sector of the Southern Ocean. Based on the longest pressure records available in the South American-Antarctic Peninsula (SAAP) sector of the Southern Oceans, zonal and meridional indices have been developed for ...

A simple model shows that acceleration of Jupiter and Saturn’s multiple jets at altitudes confined near the top of the adiabatic region (e.g., at a few bars pressure) can produce jets that penetrate deeply into the molecular envelope. This result disproves the common assertion that jet acceleration near the outer margin can only produce zonal winds that are confined to these outer layers. © 200...