A meteor radar in the UK (near 52 N) has been used to measure the mean winds of the mesosphere/lowerthermosphere (MLT) region over the period 1988–2000. The seasonal course and interannual variability is characterised and comparisons are made with a number of models. Annual mean wind trends were found to be +0.37 ms−1 yr−1 for the zonal component and +0.157 ms−1 yr−1 for the meridional componen...

Altitude profiles of temperature in the stratosphere and lower mesosphere over Gadanki (13.5 N, 79.2 E), based on lidar observations during the Equatorial Wave Study campaign (29 February–2 April 2000), showed an anomalous cooling of the stratosphere, lasting for about 4– 5 days. Immediately following this stratospheric cooling, a prominent ∼4-day period oscillation is observed in the zonal, as...

Daily surface wind variations over the equatorial eastern Pacific Ocean during summer 1992 are documented, using hourly observations from the tropical atmosphere ocean moored buoy array. Diurnal and semidiurnal variations are apparent in the zonal wind component, with peak-to-peak amplitudes of a few tenths of a meter per second. The phase of the semidiurnal cycle in zonal wind is approximately...

Wave solutions to the linearized, quasi-hydrostatic equations for adiabatic, nonviscous flow on an equatorially oriented beta plane are obtained. The basic current is assumed to be zonal and invariant in both space and time. Only solutions for which the meridional wind component is symmetric with respect to the equator are considered. Disturbances with wavelengths on the order of 103 km. are fo...

The fundamental equations are linearized by the method of small perturbations for the conditions of hydrostatic equilibrium and geostrophic balance of meridional forces. I n a first case, Fickian momentum diffusion is used; in a second case, a shearand latitude-dependent eddy viscosity is used. A wave solution for the zonal wind oscillation, having in meridional profile the shape of a probabili...

Using 16 years of NCEP–NCAR reanalysis data on the 200-mb surface, it is shown that in the deep Tropics, the horizontal transient eddy momentum flux accelerates the zonal mean zonal wind. This acceleration is mainly due to transient eddies of intraannual and interannual timescales, and to those associated with the Madden– Julian oscillation (MJO). The interannual timescale eddy fluxes are domin...

Zonal wind stress over the Southern Ocean may be responsible for a significant fraction of the meridional overturning associated with North Atlantic Deep Water. Numerical experiments by Tsujino and Suginohara imply that the zonal periodicity of the Southern Ocean is not necessary for midlatitude westerly winds to drive strong remote meridional overturning. Here, idealized numerical experiments ...

Hourly measurements from 51 moored buoys in the Tropical Atmosphere Ocean array (9°N–8°S, 165°E– 95°W) during 1993–2004 are used to document the climatological seasonal and annual mean patterns of diurnal and semidiurnal near-surface wind variability over the tropical Pacific Ocean. In all seasons, the amplitude of the semidiurnal harmonic is approximately twice as large as the diurnal harmonic...

[1] Observational analysis has shown that when El NiñoSouthern Oscillation (ENSO) events typically reach their peak amplitude in boreal winter, the associated zonal wind anomalies abruptly shift southward so that the maximum anomalous zonal wind is located around 5 –7 S. Here, an analysis utilizing multiple wind products identifies a clear ENSO phase nonlinearity in the extent of this meridiona...

The semiannual cycle in zonal wind over the equatorial Indian Ocean is investigated by use of ocean– atmospheric reanalyses, and linear ocean–atmospheric models. In observations, the semiannual cycle in zonal wind is dominant on the equator and confined in the planetary boundary layer (PBL). Results from a momentum budget analysis show that momentum advection generated by the cross-equatorial m...