Skip to main content
Earth, Planets and Space
Download PDF

Automated detection of Pi 2 pulsations using wavelet analysis: 2. An application for dayside Pi 2 pulsation study

Earth, Planets and Space volume 51, pages 23–32 (1999)Cite this article

Abstract

We investigated statistical characteristics of dayside Pi 2 pulsations observed at Mineyama (25.5° geomagnetic latitude) from November 1994 through June 1996, using an algorithm to detect Pi 2 pulsations which was introduced in Part 1 of the accompanying paper. We obtained the following results. (1) The ratio of the number of Pi 2 pulsations on the dayside (06-18 MLT) to that on the nightside (18-06 MLT) was about 31%. (2) The polarization of the dayside Pi 2 pulsations changed from right-handed before local noon to left-handed after local noon. (3) Wave power of dayside Pi 2 pulsations in the H-component has a peak around local noon and dips on both dawn and dusk sides. (4) Frequency of the fundamental wave is ranging from 9 mHz to 30 mHz with dominant frequency of 17–24 mHz, and frequency ratios of the first three harmonics are 1: ( 1.7 ± 0.5): ( 2.3 ± 0.7 ). We found that the magnetospheric cavity model can explain most of these observational results.

References

  • Allan, W., F. W. Menk, B. J. Fraser, Y. Li, and S. P. White, Are low-latitude Pi 2 pulsations cavity/waveguide modes?, Geophys. Res. Lett., 23, 765–768, 1996.

    Article  Google Scholar 

  • Hughes, W. J. and D. J. Southwood, The screening of micropulsation signals by the atmosphere and ionosphere, J. Geophys. Res., 81, 3234–3240, 1976.

    Article  Google Scholar 

  • Iyemori, T. and D. R. K. Rao, Decay of the Dst field of geomagnetic disturbance after substorm onset and its implication to storm-substorm relation, Ann. Geophys., 14, 608–618, 1996.

    Article  Google Scholar 

  • Iyemori, T., T. Araki, T. Kamei, and M. Takeda, Midlatitude Geomagnetic Indices ASY and SYM (provisional) No. 1 1989, Data Analysis Center for Geomag. and Space Magnetism, Kyoto Univ., Kyoto, 1992.

    Google Scholar 

  • Kivelson, M. G. and D. J. Southwood, Hydromagnetic waves and the iono-sphere, Geophys. Res. Lett., 15, 1271–1274, 1988.

    Article  Google Scholar 

  • Lanzerotti, L. J. and L. V. Medford, Local night, impulsive (Pi 2-type) hydromagnetic wave polarization at low latitudes, Planet. Space Sci., 32, 135–142, 1984.

    Article  Google Scholar 

  • Lester, M., W. J. Hughes, and H. J. Singer, Polarization patterns of Pi 2 magnetic pulsations and the substorm current wedge, J. Geophys. Res., 88, 7958–7966, 1983.

    Article  Google Scholar 

  • Lester, M., W. J. Hughes, and H. J. Singer, Longitudinal structure in Pi 2 pulsations and the substorm current wedge, J. Geophys. Res., 89, 5489–5494, 1984.

    Article  Google Scholar 

  • Li, Y., Characteristics of low latitude Pi 2 geomagnetic pulsations, Ph.D. Thesis, University of Newcastle, New South Wales, Australia, March, 1994.

    Google Scholar 

  • Li, Y., B. J. Fraser, F. W. Menk, D. J. Webster, and K. Yumoto, Properties and sources of low and very low latitude Pi2 pulsations, J. Geophys. Res., 103, 2343–2358, 1998.

    Article  Google Scholar 

  • Lin, C. A., L. C. Lee, and Y. J. Sun, Observations of Pi 2 pulsations at a very low latitude (L = 1.06) station and magnetospheric cavity resonances, J. Geophys. Res., 96, 21105–21113, 1991.

    Article  Google Scholar 

  • Nishida, A., Geomagnetic Diagnosis of the Magnetosphere, 256 pp., Springer-Verlag, New York, 1978.

    Book  Google Scholar 

  • Nosé, M., T. Iyemori, M. Takeda, T. Kamei, D. K. Milling, D. Orr, H. J. Singer, E. W. Worthington, and N. Sumitomo, Automated detection of Pi 2 pulsations using wavelet analysis: 1. Method and an application for substorm monitoring, Earth Planets Space, 50, 773–783, 1998.

    Article  Google Scholar 

  • Saito, T. and S. Matsushita, Solar cycle effects on geomagnetic Pi 2 pulsations, J. Geophys. Res., 73, 267–286, 1968.

    Article  Google Scholar 

  • Sakurai, T. and R. L. McPherron, Satellite observations of Pi 2 activity at synchronous orbit, J. Geophys. Res., 88, 7015–7027, 1983.

    Article  Google Scholar 

  • Sastry, T. S., Y. S. Sarma, S. V. Sarma, and P. V. S. Narayan, Day-time Pi pulsations at equatorial latitudes, J. Atmos. Terr. Phys., 45, 733–741, 1983.

    Google Scholar 

  • Shinohara, M., K. Yumoto, A. Yoshikawa, O. Saka, S. I. Solovyev, E. F. Vershinin, N. B. Trivedi, J. M. Da Costa, and The 210° MM Magnetic Observation Group, Wave characteristics of daytime and nighttime Pi 2 pulsations at the equatorial and low latitudes, Geophys. Res. Lett., 24, 2279–2282, 1997.

    Article  Google Scholar 

  • Singer, H. J., W. J. Hughes, P. F. Fougere, and D. J. Knecht, The localization of Pi 2 pulsations: Ground-satellite observations, J. Geophys. Res., 88, 7029–7036, 1983.

    Article  Google Scholar 

  • Smith, B. P., On the occurrence of Pi 2 micropulsations, Planet. Space Sci., 21, 831–837, 1973.

    Article  Google Scholar 

  • Stuart, W. F. and H. G. Barsczus, Pi’s observed in the daylight hemisphere at low latitudes, J. Atmos. Terr. Phys., 42, 487–497, 1980.

    Article  Google Scholar 

  • Sutcliffe, P. R. and K. Yumoto, Dayside Pi 2 pulsations at low latitude, Geophys. Res. Lett., 16, 887–880, 1989.

    Article  Google Scholar 

  • Sutcliffe, P. R. and K. Yumoto, On cavity mode nature of low-latitude Pi 2 pulsations, J. Geophys. Res., 96, 1543–1551, 1991.

    Article  Google Scholar 

  • Takahashi, K., S. Ohtani, and B. J. Anderson, Statistical analysis of Pi 2 pulsations observed by the AMPTE CCE spacecraft in the inner magne-tosphere, J. Geophys. Res., 100, 21929–21941, 1995.

    Article  Google Scholar 

  • Villante, U., M. Vellante, M. De Biase, L. J. Lanzerotti, and L. V. Medford, Pi 2 pulsations at separated sites ( = 90°): a comparison between mid- and low-latitude observations, Ann. Geophys., 10, 472–482, 1992.

    Google Scholar 

  • Yanagihara, K. and N. Shimizu, Equatorial enhancement of micropulsation pi-2, Mem. Kakioka Mag. Obs., 12, 57–63, 1966.

    Google Scholar 

  • Yumoto, K., Evidence of magnetospheric cavity Pi 2 waves, J. Geomag. Geoelectr., 42, 1281–1290, 1990.

    Article  Google Scholar 

  • Yumoto, K., T. Saito, A. Eitoku, and Y. Kamide, A statistical study of low-latitude Pi 2’s associated with magnetospheric substorms, Proc. Symp. on Magnetosphere and Ionosphere, held at IASA, Tokyo Univ., on 27–28 Nov., 1980, pp. 139–145, 1980.

  • Yumoto, K., K. Takahashi, T. Sakurai, P. R. Sutcliffe, S. Kokubun, H. Lühr, T. Saito, M. Kuwashima, and N. Sato, Multiple ground-based and satellite observations of global Pi 2 magnetic pulsations, J. Geophys. Res., 95, 15175–15184, 1990.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Faculty of Science, Kyoto University, Kyoto, 606-8502, Japan

    M. Nosé

Authors
  1. M. Nosé
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to M. Nosé.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Nosé, M. Automated detection of Pi 2 pulsations using wavelet analysis: 2. An application for dayside Pi 2 pulsation study. Earth Planet Sp 51, 23–32 (1999). https://doi.org/10.1186/BF03352206

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03352206

Keywords

  • Power Spectral Density
  • Wavelet Analysis
  • Frequency Ratio
  • Automate Detection
  • Geomagnetic Latitude