- Open Access
Characteristics of Pi 2 magnetic pulsations observed at the CPMN stations: A review of the STEP results
Earth, Planets and Space volume 53, pages981–992(2001)
From analyses of magnetic data from the Circum-pan Pacific Magnetometer Network (CPMN) stations, we can find the following wave characteristics of Pi 2 magnetic pulsations. (1) Pi 2 pulsations observed on the ground are an ensemble of various hydromagnetic modes excited at high, middle, low, and equatorial latitudes. Each mode exhibits its own propagation (timing) and spatial illumination. (2) There are apparent longitudinal propagation and latitudinal time delays of the maximum Pi 2 magnetic energy among the CPMN stations within 100 sec. (3) When a single low-latitude station is located in the sectors of 00–24 hr LT, 20–03 hr local time (LT), and 23-01 hr LT, respectively, 62%, 79%, and 100% of auroral breakups identified by the Polar satellite have associated Pi 2s. 66% of the low-latitude Pi 2s occur within 1 min of the auroral breakups, and 85% within 2 min. Pi 2s are still a good indicator of substorm onsets, but they should be used with care.
Chen, L. and A. Hasegawa, A theory of long-period magnetic pulsations, 1, Steady state excitation of field line resonances, J. Geophys. Res., 79, 1024–1032, 1974a.
Chen, L. and A. Hasegawa, A theory of long-period magnetic pulsations, 2, Impulse excitation of surface eigenmode, J. Geophys. Res., 79, 1033–1037, 1974b.
Cheng, C.-C., J.-K. Chao, and K. Yumoto, Spectral power of low-latitude Pi 2 pulsations at the 210° magnetic meridian stations and plasmaspheric cavity resonances, Earth Planets Space, 52, 615–627, 2000.
Lester, M., H. J. Singer, D. P. Smits, and W. J. Hughes, Pi 2 pulsations and the substorm current wedge: Low-latitude polarization, J. Geophys. Res., 94, 17133–17141, 1989.
Li, Y., K. Yumoto, M. Itonaga, M. Shinohara, T.-I. Kitamura, and the 210° MM group, Equatorial Pi 2’s as indicators of substorms and the relation between dayside and nightside Pi 2’s, in SUBSTORMS-4, Edited by S. Kokubun and Y. Kamide, pp. 555–558, Terra Scientific Publ. Comp/Kluwer Academic Publ., 1998a.
Li, Y., K. Yumoto, K. Liou, S. Otani, and C.-I. Meng, Pi 2 pulsations as indicators of the substorms, Abstract of the Fall Meeting of AGU, San Francisco, on Dec. 6–10, 1998, 1998b.
Li, Y., K. Yumoto, and the 210° MM Magnetic Observation Group, Local time dependence of Pi 2 pulsations observed along the 210° magnetic meridian, Mem. Fac. Sci., Kyushu Univ., 31(1), 11–18, 2000.
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, 21105–21114, 1991.
Liou, K., C.-I. Meng, A. T. Lui, P. T. Newell, M. Brittnacher, G. Parks, and M. Nose, A fresh look at substorm onset identifiers, in SUBSTORMS-4, edited by S. Kokubun and Y. Kamide, pp. 247–252, Terra Scientific Publ. Comp/Kluwer Academic Publ., 1998.
Liou, K., C.-I. Meng, P. T. Newell, K. Takahashi, S.-I. Ohtani, and A. T. Lui, Evaluation of low-latitude Pi 2 pulsations as indicator of substorm onset using Polar ultraviolet imagery, J. Geophys. Res., 105, 2495–2505, 2000.
Liou, K., P. T. Newell, D. G. Sibeck, C.-I. Meng, M. Brittnacher, and G. Parks, Observation of IMF and seasonal effects in the location of auroral substorm onset, J. Geophys. Res., 106, 5799–5810, 2001a.
Liou, K., C.-I. Meng, P. T. Newell, A. T. Lui, G. D. Reeves, and R. D. Belian, Particles injections with auroral expansions, J. Geophys. Res., 106, 5873–5881, 2001b.
McPherron, R. L., C. T. Russel, and M. P. Aubry, Satellite studies of magnetospheric substorms on August 15, 1968, Phenomenological model for substorm, J. Geophys. Res., 78, 3131–3149, 1973.
Ohtani, S., F. Creutzberg, T. Mukai, H. Singer, A. T. Y. Lui, M. Nakamura, P. Prikryl, K. Yumoto, and G. Rostoker, Substorm onset timing: The December 31, 1995 event, J. Geophys. Res., 104, 17499–17520, 1999.
Olson, J.V., Pi 2 pulsations and substorm onsets: A review, J. Geophys. Res., 104, 17499–17520, 1999.
Osaki, H., K. Yumoto, K. Fukao, K. Shiokawa, F. W. Menk, B. J. Fraser, and the 210° MM Magnetic Observation Group, Characteristics of low-latitude Pi 2 pulsations along the 210° magnetic meridian, J. Geomag. Geoelectr., 48, 1421–1430, 1996.
Osaki, H., K. Takahashi, H. Fukunishi, T. Nagatsuma, H. Oya, A. Matsuoka, and D. K. Milling, Pi 2 pulsations observed from the Akebono satellite in the plasmasphere, J. Geophys. Res., 103, 17605–17615, 1998.
Saito, T., Geomagnetic pulsations, Space Sci. Rev., 10, 319–412, 1969.
Saito, T., K. Yumoto, and K. Koyama, Magnetic pulsation Pi 2 as a sensitive indicator of magnetic substorm, Planet. Space Sci., 24, 1025–1029, 1976.
Sakurai, T. and T. Saito, Magnetic pulsation Pi 2 and substorm onset, Planet Space Sci., 24, 573–577, 1976.
Samson, J. C. and G. Rostoker, Latitude-dependent characteristics of high latitude Pc 4 and Pc 5 micropulsations, J. Geophys. Res., 77, 6133–6144, 1972.
Shinohara, K., 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(18), 2279–2282, 1997.
Solovyev, S. I., D. G. Baishev, E. S. Barkova, N. E. Molochushkin, and K. Yumoto, Pi 2 magnetic pulsations of auroral arc current system, Geophys. Res. Lett., 27(13), 1839–1842, 2000.
Southwood, D. J., Some features of field line resonance in the magnetosphere, Planet. Space Sci., 22, 483–491, 1974.
Stuart, W. F., A mechanism of selective enhancement of Pi 2s by the plasmapause, J. Atmos. Terr. Phys., 36, 851–859, 1974.
Sutcliffe, P. R. and K. Yumoto, On the cavity mode nature of low-latitude Pi 2 pulsations, J. Geophys. Res., 96, 1543–1551, 1991.
Tachihara, H., M. Shinohara, M. Shimoizumi, O. Saka, and T.-I. Kitamura, Magnetometer system for studies of the equatorial electrojet and micropulsations, J. Geomag. Geoelectr., 48, 1311–1319, 1996.
Takahashi, K., S. Ohtani, and K. Yumoto, AMPTE CCE observations of Pi 2 pulsations in the inner magnetosphere, Geophys. Res. Lett., 19, 1447–1450, 1992.
Takahashi, K., S. I. Ohtani, and B. J. Anderson, Statistical analysis of Pi 2 pulsations observed by the AMPTE CCE spacecraft in the inner magnetosphere, J. Geophys. Res., 100, 21929–21941, 1995.
Takahashi, K., B. J. Anderson, and K. Yumoto, Upper Atmospheric Research Sattelite observation of a Pi 2 pulsation, J. Geophys. Res., 104, 25035–25045, 1999.
Uozumi, T, Study on generation and propagation mechanisms of Pi 2 magnetic pulsations; Toward the identification of the substorm onset region, Thesis for the Degree of Doctor of Science in Kyushu University, Sept. 25, 2000.
Uozumi, T, K. Yumoto, H. Kawano, A. Yoshikawa, J. V. Olson, S. I. Solovyev, and E. F. Vershinin, Characteristics of energy transfer of Pi 2 magnetic pulsations: Latitudinal dependence, Geophys. Res. Lett., 27(11), 1619–1623, 2000.
Yeoman, T. K. and D. Orr, Phase and spectral power of mid-latitude Pi 2 pulsations: evidence for a plasmasphere cavity resonances, Planet. Space Sci., 37, 1367–1383, 1989.
Yeoman, T. K., M. P. Freeman, G. D. Reeves, M. Lester, and D. Orr, A comparison of mid-latitude Pi 2 pulsations and geostationary orbit particle injections as substorm indicators, J. Geophys. Res., 99, 4085–4093, 1994.
Yumoto, K., Generation and propagation mechanisms of low-latitude magnetic pulsations—A review, J. Geosphys., 60, 79–105, 1986.
Yumoto, K., External and internal sources of low-frequency MHD waves in the magnetosphere—A review, J. Geomag. Geoelectr., 40, 293–311, 1988.
Yumoto, K., Evidence of magnetic cavity Pi 2 waves, J. Geomag. Geoelectr., 42, 1281–1290, 1990.
Yumoto, K. and The 210° MM Magnetic Observation Group, Initial results from the 210° magnetic meridian project—Review, J. Geomag. Geoelectr., 47, 1197–1213, 1995.
Yumoto, K. and the 210° MM Magnetic Observation Group, The STEP 210° magnetic meridian network project, J. Geomag. Geoelectr., 48, 1297–1309, 1996.
Yumoto, K., K. Takahashi, T. Saito, F. W. Menk, B. J. Fraser, T. A. Potemra, and L. J. Zanetti, Some aspects of the relation between Pi 1–2 magnetic pulsations observed at L = 1.3 − 2.1 on the ground and substorm-associated magnetic field variations in the near-earth magnetotail observed by AMPTE/CCE, J. Geophys. Res., 94, 3611–3618, 1989.
Yumoto, K, H. Osaki, K. Fukao, K. Shiokawa, Y. Tanaka, S. I. Soloveyev, G. Krymskij, E. F. Vershinin, V. F. Osinin, and 210° MM Magnetic Observation Group, Correlation of high- and low-latitude Pi 2 magnetic pulsations observed at 210° magnetic meridian chain stations, J. Geomag. Geoelectr., 46, 925–935, 1994.
About this article
Cite this article
Yumoto, K. Characteristics of Pi 2 magnetic pulsations observed at the CPMN stations: A review of the STEP results. Earth Planet Sp 53, 981–992 (2001). https://doi.org/10.1186/BF03351695
- Magnetic Pulsation
- Polar Satellite
- Substorm Onset
- Substorm Current Wedge
- Magnetic Meridian