Abstract

A study has been made of the possible relationships between the time variations of winds at one level and those at another in the stratosphere and upper troposphere, on either side of the equator, using the rocket meteorological data of Fort Sherman (9°20′N) and Ascension Island (7°59′S) for the seasons June solstice (j), equinox (e) and December solstice (d), and for the years 1967–68. A good positive correlation exists among the zonal winds at different levels over both Fort Sherman and Ascension Island, between the time variations of winds at 40 km and those at 36, 28 and 20 km, in all the seasons; that is, an increase of wind speed at 40 km is accompanied by an increase of wind speed at 36, 28 and 20 km. At Fort Sherman a negative correlation exists between the time variations of winds at 32 km and 24 km in the e season, and between those of 32 and 20 in the d season. Over Ascension Island negative correlation exists between wind variations at 36 and 20 km and also between 32 and 20 km in the e and j seasons. From these negative correlations, it is inferred that zonal circulation cells may generally exist between 32 and 24 km and between 32 and 20 km. There is no correlation of any type among the meridional component of winds, suggesting that the stratospheric circulation in the equatorial region is mostly confined to zonal winds only. The circulations in the stratosphere and in the troposphere are independent systems. The zonal wind variations near the stratonull are always negatively correlated with wind variations at other levels, suggesting that the stratonull lends itself as an easy path for completion of the circulation cell.

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