MHD simulation of the interplanetary environment in the ecliptic plane during the 3-9 February 1986 solar and geomagnetic activity
Abstract
A numerical simulation is performed for the interplanetary medium's response to 6 solar flares that were observed, sequentially, in real time by NOAA and AWS instruments 3-7 Feb 1986. This report is of great practical interest because of the extensive geomagnetic disturbances and associated near-Earth activity that followed these flares on 6-9 Feb. The magnetohydrodynamic simulation is carried out with the Space Environment Laboratory's 2-1/2D Interplanetary Global Model code. It demonstrates the multiple, compound interactions of the interplanetary disturbances produced by these flares by using input perturbations based upon real-time optical, radio, and satellite observations. The optical (H-alpha) and radio (microwave to metric wavelength) data were obtained from the SOON/RSTN sites, and full-disk-integrated X-ray measurements were obtained from the NOAA/GOES-5 and -6 satellites. Examination of the simulated solar wind output (such as momentum flux, and cross-magnetospheric tail electric field) at Earth's position indicates that the major geomagnetic activity was probably due primarily to the second and fifth solar flares in the sixfold sequence. Predicated geomagnetic storm sudden commencement times were early by only about 4% (3-4 hours) for the pulses suggested by the consequences of the 2d and 6th flares. The 180 hour simulation, which required only 100 seconds (CPU time) on the NOAA/NBS CYBER 855/205, required 8 hours clock time on the SEL's APOLLO workstation.
- Publication:
-
Air Force Interim Report
- Pub Date:
- September 1986
- Bibcode:
- 1986aifo.reptQ....D
- Keywords:
-
- Computerized Simulation;
- Geomagnetism;
- Interplanetary Magnetic Fields;
- Ionospheric Disturbances;
- Magnetohydrodynamics;
- Real Time Operation;
- Solar Activity;
- Electric Fields;
- Magnetic Disturbances;
- Mathematical Models;
- Radio Frequencies;
- Solar Cycles;
- Solar Wind;
- X Rays;
- Solar Physics