Simultaneous observations of the cusp with IMAGE Low Energy Neutral Atoms Imager and SuperDARN radar S. Taguchi, K. Hosokawa, M.R. Collier, T.E. Moore, M.-C. Fok, A.S. Yukimatu, N. Sato, and R.A. Greenwald The Low Energy Neutral Atom (LENA) imager on the IMAGE spacecraft observed significant emission in the high-latitude magnetosheath direction during an extreme solar wind condition on April 11, 2001. The emission was modulated in such a manner that the sources shifted equatorward in the high-latitude sheath while sometimes undergoing brief poleward returns. This modulation and the IMF BZ tend to have correlative variations. During this interval of interest, SuperDARN was receiving strong backscattered signals from large potions of the dayside ionosphere. This observation indicates that the equatorward motion of the cusp latitude consists of rapid and slow phases. This kind of equatorward shift appears to correlate with the motion of the emission observed by LENA in the direction of the high-latitude sheath, which gives evidence for a means for monitoring the high-altitude cusp using IMAGE/LENA. It thus appears that the two remote sensing observations, i.e., IMAGE/LENA and SuperDARN radar would provide promising opportunities to understand the detailed dynamics of the polar cusp extending from the low-altitudes to the high-altitudes. _______________ Advances in Polar Upper Atmosphere Research, NIPR, 18, 53-64, 2004.