ISSN:
1573-1626
Source:
Springer Online Journal Archives 1860-2000
Topics:
Architecture, Civil Engineering, Surveying
,
Geosciences
,
Physics
Description / Table of Contents:
Summary The monthly means of the geomagnetic index aa and of the relative sunspot numbers were used to analyse the quasi-biennial oscillations (QBO) in geomagnetic activity related to an analogous variation in solar activity. Statistical methods of time series analysis were applied: autocorrelation and power spectrum, cross-correlation, complex demodulation, and the digital filter technique. The aim of this investigation was not only the detection of QBO in geomagnetic activity, which has been done by various authors, but also the determination of the time variation of the period, phase and amplitude of these oscillations in the given time interval with reference to the results of Apostolov [2] and Apostolov and Letfus [4]. The following main results have been obtained: The characteristic period of QBO in geomagnetic activity is shorter and varies in a narrower interval than that in sunspot activity; the lifetime of the oscillations is about 22 years and roughly coincides with Hale's cycle; the amplitude of QBO in geomagnetic activity has its maximum on the decreasing branch of the sunspot cycle; the QBO in geomagnetic activity follows the analogous variation in sunspot activity with a delay of 2 to 6 months for various solar cycles, as compared with the 3 to 22 moths for the raw, unfiltered data. The causes of the differences in the characteristics of QBO in geomagnetic and sunspot activity are considered and it is shown that these differences do not contradict the solar control of this phenomenon.
Notes:
Резюме Месячные сре¶rt;нuегеомaгнumного uн¶rt;ексa aa u оmносumельного чuслa солнечных nяmен uссnользовaлuсь ¶rt;ля aнaлuзa квaзu¶rt;вухлеmнuх осцuлляцuŭ (КДО) вгеомaгнumнoŭ aкmuвносmu, связaнных со сооmвеmсmвующuмu вaрuaцuямu солнечноŭ aкmuвносmu. Иссnользовaлuсь сле¶rt;ующuе сmamuсmuческuе меmо¶rt;ы aнaлuзa временных ря¶rt;ов: сnекmр мощносmu, aвmокоррелaцuонныŭ u кроскорреляцuонныŭ aнaлuз, комnлекснaя ¶rt;емо¶rt;уляцuя, цuфровaя фuльmрaцuя. Цель эmого uссле¶rt;овaнuя не mолько вы¶rt;еленuе КДО uзгеомaгнumноŭ aкmuвносmu, чmо было с¶rt;елaно рaзнымu aвmорaмu, но вмесmе с mем оnре¶rt;еленuе временных вaрuaцuŭ nерuо¶rt;a, фaзы u aмлnumу¶rt;ы еmuх осцuлляцuŭ ¶rt;ля ¶rt;aнного uнmервaлa временu, учumывaя резульmamы Аnосmоловa [2] u Аnосmоловa u Леmфусa [4]. Былu nолучены сле¶rt;ующuе основные резульmamы: хaрaкmерuсmuческuŭ nерuо¶rt; КДО вгеомaгнumноŭ aкmuвносmu меньше u uзменяеmся в более узком uнmервaле чем КДО в aкmuвносmu солнечных nяmен; время жuзнu осцuлляцuŭ nрuблuзumельно рaвно 22го¶rt;aм u связaно с цuклом Хеŭлa; aмnлumу¶rt;a КДО вгеомaгнumноŭ aкmuвносmu ¶rt;осmuгaеm мaксuмaльноŭ велuчuны нa сna¶rt;aющеŭ веmвu цuклa солнечных nяmен; КДО вгеомaгнumноŭ aкmuвносmu сле¶rt;уеm aнaлогuчную вaрuaцuю в aкmuвносmu солнечных nяmен с оnоз¶rt;aнuем с 2 nо 6 месaцев ¶rt;ля рaзных солнечных цuклов nо срaвненuю с оnоз¶rt;aнuем с 3 nо 22 месaцев ¶rt;ля нефuльmрuровaных nервонaчaлыньх ¶rt;aнных. Обсуж¶rt;aюmся nрuчuны рaзлuчuя хaркamерuсmuк КДО вгеомaрнumноŭ u солнечноŭ aкmuвносmьях u nокaзaно, чmо эmu рaзлuчuя не nроmuворечяm солнечному конmролю эmого явленuя.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01637580
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