Prediction of the solar corona on December 14, 2020.
With low-resolution Daily-update MHD simulations
From daily-updated MHD simulations,
we can make several types of prediction that can be compared with the actual eclipses seen from the ground.
One daily simulation with 0.15 million grids takes usually two hours on an 8-core node.
In the figure below, from left to right,
coronal magnetic field lines colored with plasma speed (within 2.5 Rs),
field lines (within 5 Rs) and photospheric magnetic field,
base of open-field regions (coronal holes) and brightness of coronal streamers are shown.
These plots are automatically updated when a daily MHD simulation is completed (usually 11:30AM to noon PST).
(click here to enlarge, or
get an mpeg movie combining daily-simulation plots since 2020 Nov. 24)
Left: Magnetic field lines with colors representing bulk speed of the solar coronal plasma
(blue for 5km/s or less, green for 50km/s, and red for 100 km/s), in the solar corona (between 1 to 3.5 solar radii).
Middle: Coronal magnetic field lines within 5 solar radii.
Right: Coronal plasma density normalized with an approximate Newkirk filter fucntion (out of the solar disk)
and solar-surface bases of the open-field coronal hole regions.
The view point is set at the approximate position of the Earth on December 14, 2020 (approximately CR 2238, 147.4 degrees Carrington longitude, and 0.6 degrees latitude South).
In these three, the solar North is up.
In other words, these plots do not show how the solar corona at the eclipes will look like to ground observers.
These plots are updated regularly around 11:30AM PST immediately after a daily coronal MHD simulation is completed.
The daily MHD runs are done in a rather low spatial resolution.
See below for the prediction made with a bit higher spatial resolution that offers a slightly better demonstration.
With a moderate-resolution MHD simulation
The /visualizations of the eclipse prediction, from a moderate-resolution (with about 4 million computation grid cells) MHD simulation of solar corona using the daily-updated synoptic map made on 2020 Nov. 24 (about 3 weeks before the eclipse).
(click here to enlarge)
Last update : 2020 December 8 (text), 2020 December 4 (plots of higher-resolution simulation)
K. Hayashi
