Physics
Scientific paper
Dec 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001soph..204..361j&link_type=abstract
Solar Physics, v. 204, Issue 1/2, p. 361-375 (2001).
Physics
21
Scientific paper
We study the development of the terrestrial ring current during the time interval of 13 18 July, 2000, which consisted of two small to moderate geomagnetic storms followed by a great storm with indices Dst=-300 nT and Kp=9. This period of intense geomagnetic activity was caused by three interplanetary coronal mass ejecta (ICME) each driving interplanetary shocks, the last shock being very strong and reaching Earth at ˜ 14 UT on 15 July. We note that (a) the sheath region behind the third shock was characterized by B z fluctuations of ˜35 nT peak-to-peak amplitude, and (b) the ICME contained a negative to positive B z variation extending for about 1 day, with a ˜ 6-hour long negative phase and a minimum B z of about -55 nT. Both of these interplanetary sources caused considerable geomagnetic activity ( Kp=8 to 9) despite their disparity as interplanetary triggers. We used our global ring current-atmosphere interaction model with initial and boundary conditions inferred from measurements from the hot plasma instruments on the Polar spacecraft and the geosynchronous Los Alamos satellites, and simulated the time evolution of H+, O+, and He+ ring current ion distributions. We found that the O+ content of the ring current increased after each shock and reached maximum values of ˜ 60% near minimum Dst of the great storm. We calculated the growth rate of electromagnetic ion cyclotron waves considering for the first time wave excitation at frequencies below O+ gyrofrequency. We found that the wave gain of O+ band waves is greater and is located at larger L shells than that of the He+ band waves during this storm interval. Isotropic pitch angle distributions indicating strong plasma wave scattering were observed by the imaging proton sensor (IPS) on Polar at the locations of maximum predicted wave gain, in good agreement with model simulations.
Dotan Yaniv
Farrugia Charles J.
Fennell Joseph F.
Jordanova Vania K.
Mansergh Thorne Richard
No associations
LandOfFree
Ring Current Dynamics during the 13 18 July 2000 Storm Period does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Ring Current Dynamics during the 13 18 July 2000 Storm Period, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ring Current Dynamics during the 13 18 July 2000 Storm Period will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1375297