A Tidal Experiment in the Equatorial Stratosphere over Ascension Island

Abstract

Twenty-four meteorological rocket soundings were made from Ascension Island (70 591 S, 140 28' W) on 11-13 April 1966. In contrast to results obtained at White Sands Missile Range, New Mexico, the smoothed wind data did not display a consistent well-defined diurnal oscillation. However, results from the temperature data showed a 1 significant diurnal variation. The time of maximum temperature ranged from 1400 LST at 36 km, to 1000 LST aS 48 km, to near 1200 LST at 60 km. The maximum diurnal range was 12 C at 44 and 60 km. Temperature results were in general agreement with the White Sands Missile Range data.

Review lecture - Rocket studies of atmospheric tides

“…B o th com ponents displayed am plitudes of ab o u t 12 m /s n ear th e stratopause (52-56 km ) w ith th e phase of th e m eridional com ponent leading th e zonal com ponent b y ab o u t 5-7 h. W hen this series of d a ta was com bined w ith previous W hite Sands d ata, it was concluded th a t an unm istakable, dom inant, diurnal tid al oscillation existed in th e strato p au se region over th is site particu larly in th e m eridional com ponent during m ost or all seasons. I n contrast to these results, a series of 24 launchings over a 2-day period in A pril 1966 a t Ascension Islan d did n o t display a consistent, well-defined diurnal oscillation in either wind com ponent (Beyers & Miers 1968). I t was concluded th a t th e diurnal variation m ay have been m asked or distorted b y some other short-term disturbance a t th e tim e of observation or th a t tid al m otion m ay be inherently more complex a t an equatorial station.…”

An Observational Study of Middle Atmospheric Diurnal Tides over Trivandrum (8.5.DEG.N, 77.DEG.E).

“…Rayleigh lidars can provide useful information in this region (e.g., CHANIN and HAUCHECORNE, 1981;GILLE et al, 1991). In this region, however, observations on tides have come mainly from rocket experiments (e.g., BEYERS et al, 1966;BEYERS and MIERS, 1968;REED et al, 1969;GROVES, 1974GROVES, , 1975GROVES, , 1980. Most of these studies correspond to high and middle latitude regions and there is relative scanty information on tides in the equatorial middle atmosphere.…”