4-7 April 2000
Solar Observations from SOHO
April 04, 2000
Disturbed Storm Time Index Plot
SuperDARN Convection Movie
British Antarctic Survey Data
Plots from Dynasonde, Magnetometer, Riometer, VLF receiver, SHARE radar and TULA ASC
Geosynchronous Particle Data
CANOPUS Magnetometer Data
April 4-7 EVENT SUMMARY - in progress|
From Simon Plunkett (SOHO/LASCO)
LASCO and EIT observed a full halo event on 2000/04/04. The CME was first observed in a C2 frame at 16:32 UT, following a data gap of about ninety minutes. The leading edge of the CME had already left the C2 field of view at this time. Measurements in C3 indicate a plane-of-sky speed of 984 km/s at PA 260 (W limb). The event was brightest and most structured over the West limb, where a bright core was observed behind the leading edge. The appearance was more diffuse and fainter in the east.
EIT observed a C9 flare in AR 8933 (N18 W58) at 15:24 UT, that was probably associated with this flare. A large area of dimming between AR 8933 and AR 8935 (S07 W34) was also observed in EIT around the same time.
From Mike Kaiser (WIND/WAVES)
WAVES observes a continuation of the metric type II in the frequency range from about 9 to 14 MHz between 15:45 and 16:00.
San Vito reported an intense type IV at about the same time as the WAVES event, so it is possible that we just observed the low frequency extent of the type IV.
GEOPHYSICAL ACTIVITY FORECAST: The Geomagnetic field is expected to be at strong
storm levels for much of April 6-7, 2000. The field is expected to return to unsettled
levels by the end of the period.
From Daniel Berdichevsky
Strong IP shock was observed by ACE-NRT (~250RE UPSTREAM OF EARTH) at ~1600UT, Apr. 6, 2000
ACE-NRT observations with SWEPAM and MAG indicate a possible compression of
a factor 4 at the time of the IP shock. SHock that appears related to the
"C9/2F FLARE AT 04/1541UT" (4/4/2000).
From Don Fairfield
On April 6, 2000 Geotail detected the interplanetary shock arrival in the afternoon magnetosheath (Xse=8.7 Yse=10.5, Zse=-2.4) at 1639:55, which was 7 minutes 48 s after Wind detected the shock at 1632:07 at X=55.1, Y=39.4, Z=-6.1. (46.4Re/468s=632km/s which is slightly faster than the measured solar wind speed behind the shock.) Some 95 seconds after detecting the interplanetary shock in the magnetosheath, Geotail passed through the earthward moving bow shock (1641:30). Geotail measured 50-70 nT southward fields in the magnetosheath during the 6 hours following 1730 while Wind measured the approximately 20 nT southward interplanetary fields that produced the large magnetic storm. Geotail detected 7 additional bow shock crossings in the 70 minutes after the initial crossing and many more during the first 10 hours of April 7. Geotail moved into the magnetotail at about 1700 April 7 when the solar wind pressure abruptly decreased.
Other Links of Interest:
Official NASA Contact: ISTP-Project
/ NASA Home / Goddard Space Flight Center Home /
Last Updated: 04/21/00