ISSN:
1436-5065
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geography
,
Physics
Description / Table of Contents:
Zusammenfassung Die Schwankungen des mittleren zonalen Windes und der mittleren Temperatur wurden von Jahr zu Jahr aus Raketensondendaten für Januar für die Sechsjahres periode 1970–1972 und 1974–1976 untersucht. Dabei wurden deutliche Veränderungen des zonalen Windes nördlich von 35–40° nördl. Breite nachgewiesen. In der Stratosphäre (25–45 km) erreichte der zonale Westwind sein Maximum 1970–1971 und 1975 zwischen 35 und 40° nördl. Breite, dagegen 1972, 1974 und 1976 nahe 60°N, wo der Polarjet auftritt. Im Niveau der Stratopause (50 km) wurde eine Veränderung des Temperaturgradienten zwischen niedrigen und polaren Breiten festgestellt. Der Gradient war 1970, 1971 und 1975 größer als 1972, 1974 und 1976. Parallel dazu wurde der Niederschlag des folgenden Sommermonsuns (Juni bis September) untersucht. 1972, 1974 und 1976 war der Monsun schwach bis normal, 1970, 1971 und 1975 normal bis stark.
Notes:
Summary The interannual variability of the mean zonal wind and the mean temperature, obtained from the rocketsonde data for January (symbolizing winter), of the middle atmosphere over the Northern Hemisphere for the 6-year period, 1970–1972 and 1974–1976 has been investigated. The stations considered for the study are Thule, Poker Flat, Fort Churchill, Wallops Island, Cape Kennedy, Fort Sherman, Kwajalein and Ascension Island. The study has shown marked interannual variation in the zonal wind northward of 35–40°N. In the stratosphere (25–45 km), the westerly zonal wind reached its maximum during 1970, 1971 and 1975 near 35–40°N whereas it reached its maximum during 1972, 1974 and 1976 near 60°N, where the polar night jet is located. At stratopause level (50 km), the temperature gradient between equator-middle latitude and the polar region showed interannual variability. The gradient was stronger during 1970, 1971 and 1975 than during 1972, 1974 and 1976. The rainfall activity of the following summer monsoon (June–September) over India during the 6-year period of study has also been examined. The monsoon was weak to normal during 1972, 1974 and 1976 when the maximum westerly flow was strong, stable and located at its normal position (near 60°N), and the equator-middle latitude to pole temperature gradient at stratopause level was weak. The monsoon was normal to strong during 1970, 1971 and 1975 when the maximum westerly flow was weak, diffuse and shifted south-ward (35–40°N) and the equator-middle latitude to pole temperature gradient at stratopause level was strong.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01029525
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