Wavelet Analysis of solar, solar wind and geomagnetic parameters

• Published in: Solar physics Vol. 208; no. 2; pp. 359 - 373
• Main Authors: Prabhakaran Nayar, Sr, Radhika, Vn, Revathy, K, Ramadas, V
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.08.2002
• Subjects: Magnetic fields; Solar physics; Sun; Wind speed
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1023/A:1020565831926

The sunspot number, solar wind plasma, interplanetary magnetic field, and geomagnetic activity index A^sub p^ have been analyzed using a wavelet technique to look for the presence of periods and the temporal evolution of these periods. The global wavelet spectra of these parameters, which provide information about the temporal average strength of quasi periods, exhibit the presence of a variety of prominent quasi periods around 16 years, 10.6 years, 9.6 years, 5.5 years, 1.3 years, 180 days, 154 days, 27 days, and 14 days. The wavelet spectra of sunspot number during 1873-2000, geomagnetic activity index A^sub p^ during 1932-2000, and solar wind velocity and interplanetary magnetic field during 1964-2000 indicate that their spectral power evolves with time. In general, the power of the oscillations with a period of less than one year evolves rapidly with the phase of the solar cycle with their peak values changing from one cycle to the next. The temporal evolution of wavelet power in R^sub z^, v^sub sw^, n, B^sub y^, B^sub z^, |B|, and A^sub p^ for each of the prominent quasi periods is studied in detail.[PUBLICATION ABSTRACT]