The field of views of the Syowa East HF radar covers over Zhongshan Station (magnetic latitude ~ 74. 5°S). We examined the relation between HF radar signatures and optical aurora by using the data obtained on 3 Augusl 1997. A geomagnetic negative sudden impulse (SI-) occurred at ~ 1432 UT on 3 August 1997associated with the sudden decrease of solar wind plasma density. From the behavior of the optical aurora observed by all-sky TV camera and scanning photometers at Zhongshan Station, a sudden enhancement of auroral emission intensity and poleward moving signature occurred associated with the negative SI. It is intcresting that the temporal and spatial variations of the HF radar backscatter power showed one to one correlations with optical aurora data. The details of this event are examined and compared with the data onboard WIND sate1lite and from ground based magnetometers.
Simultaneous observations of Syowa East HF radar and Zhongshan Station optical aurora associated with the solar wind negative pressure impulse
1 Araki T, Nagano H.1988. Geomagnetic response to sudden expansions of the magnetoshcrc. J. Gcophys. Res., 93:3983-3988. DOI:10.1029/JA093iA05p03983
2 Greenwald RA, Baker KB, Dudeny JR, Pinnock M, Jones TB, Thomas EC, Villain J-P, Cerisier J-C. Senior C, Hanuise C, Hunsucker RD, Sofko G, Koehler J, Nielsen E, Pellinen R, Walker ADM, Sato N, Yamagishi H (1995) : A global view of the dynamics of high-latitude convection. Space Sci. Rev., 71:761-796.
3 Hirasawa T.1981. Effects of magnetospheric compression and expansion on spectral structure of UI.F emissions: Mem. Natl. Inst. Polar Res. 18:127-151.
4 Kaufman R, Lt Walker DN (1974) : Hydromagnetic waves excited during a SSC. J. Geophys. Res., 79: 5187-5195. DOI:10.1029/JA079i034p05187
5 LiihrH, Aylward A, Buchert SC, Pajunpää A, Pajunpää K, Holmboe T, Zalewski SM.1998. Westward movement dynamic substorm features observed with the IMAGE magnetometer network and olher ground-based instruments. Annales Geophysicae, 16:425-440. DOI:10.1007/s00585-998-0425-y
6 Matsushita S.1961. Increase of ionization associated with geomagnetic sudden commcncemenis. J. Geophys. Res., 66:3958-3961. DOI:10.1029/JZ066i011p03958
7 Oglivie K, Parks GK.1996. First results from WIND spacecraft. Geophys. Res. Lett., 23: 1176-1181.
8 Sibeck DG, Baumjohann W, Lopez RE.1989. Solar wind dynamic pressure variations and transient magnetospheric signatures. Geophys. Res. Lett., 16:13-16.