Low-Latitude Auroras Observed at Moshiri and Rikubetsu (L=1.6) during Magnetic Storms on February 26, 27, 29, and May 10, 1992.

Abstract

This paper reports latitudinal and longitudinal movements of four low-latitude auroras observed by a meridian scanning photometer and an all-sky TV camera at Moshiri and Rikubetsu (L = 1.6) in Japan during magnetic storms. It is observationally found that the low-latitude auroras occur in the region of L -2 even during moderate magnetic storms. The auroras which are characterized by 6300-A emissions of several kR are also found to take place associated with magnetospheric substorm activity during the maximum phase of magnetic storms. The auroras and associated current systems inferred from ground magnetic field fluctuations tend to expand from midnight toward both the dawnside and the duskside. It is suggested that the observed low-latitude auroras are excited by precipitating low-energy electrons originated in the plasmasphere. We discuss generation mechanisms of these electrons based on the observations.

Initial Results from the 210.DEG. Magnetic Meridian Project-Review.

“…Optical instrumentations (photometers, all-sky television cameras) were used to identify six occurrences of subvisual low-latitude aurorae at Moshiri and Rekubetsu (0= 43.46°N, 0=143.77°E, L = 1.6) in Hokkaido, Japan, during the period from February 1992 to September 1993 (Shiokawa et al, 1994).…”

The STEP 210.DEG. Magnetic Meridian Network Project.

“…Using data from the 210° MM network stations and satellites, we are studying the STEP objective and obtaining preliminary results (see . The scientific items and related publications are as follows: (1) magnetospheric response to interplanetary shocks and discontinuities (sudden commencements [sc] and sudden impulses [si]) (Araki et al, 1997;Yumoto et al, 1994bYumoto et al, , 1996aYumoto et al, , 1996bPetrinec et al, 1996), (2) the global dynamics of low-and high-latitude auroras (Shiokawa et al, , 1995a(Shiokawa et al, , 1995b(Shiokawa et al, , 1996b(Shiokawa et al, , 1996c(Shiokawa et al, , 1996dYumoto et al, 1994aYumoto et al, , 1994c, (3) relations between in situ and ground (or separated ground) observations of substorm phenomena (Kawano et a1.,1994(Kawano et a1., ,1996Kokubun et al, 1996;Nakamura et al, 1996;Shiokawa et al, 1996), (4) global characteristics of Pc 3 waves (Yumoto et al, 1992;Menk and Yumoto, 1994;Matsuoka et al, 1997) and Pi 2 waves (Yumoto et al, 1994d;Osaki et al, 1996;Shiokawa et al, 1996c), (5) mass loading effect on Pc 3 waves in the low-latitude ionosphere Pilipenko et al, 1996), and (6) miscellaneous (earthquake-related ULF waves (Hayakawa et al, 1996) and geophysical induction current (Yumoto and Utada, 1993;Seto et al, 1996)). …”

“…Low-latitude aurorae provide evidence that solar wind energy can be transferred into the inner magnetosphere around L = 2.5 during magnetic storms (Yumoto and Utada, 1993;Yumoto et al, 1994aYumoto et al, , 1994cShiokawa et al, 1994Shiokawa et al, , 1995aShiokawa et al, , 1996bShiokawa et al, , 1996d.…”

Auroral Observations Using Automatic Optical Instruments: Relations with Multiple Pi 2 Magnetic Pulsations.

“…The operation at Canberra is carried out in cooperation with IPS Radio and Space Services, Australia. Low-latitude auroras were observed at these stations on February, 26, 27, and 29, and May 10, 1992, and on September 13, 1993 (see Shiokawa et al (1994Shiokawa et al ( , 1995b and Yumoto et al (1994) …”