PROPAGATION
A Quick Look at Current Cycle 24/25 Conditions
(Data rounded to nearest whole number)
Sunspots:
Observed Monthly, May 2020: 0
12-month smoothed, November 2019: 2
10.7-cm Flux:
Observed Monthly, May 2020: 69
12-month smoothed, November 2019: 69
Ap Index:
Observed Monthly, May 2020: 6
12-month smoothed, November 2019: 6
One Year Ago: A Quick Look at Solar Cycle Conditions
(Data rounded to nearest whole number)
Sunspots:
Observed Monthly, May 2019: 6
12-month smoothed, November 2018: 4
10.7-cm Flux:
Observed Monthly, May 2019: 71
12-month smoothed, November 2018: 70
Ap Index:
Observed Monthly, May 2019: 7
12-month smoothed, November 2018: 7
Space is not a vacuum, at least in our solar system. The sun’s atmosphere, which actually extends extremely far out from the sun, fills space in our system with plasma, a low-density gas in which the individual atoms are charged.
The temperature of the sun’s atmosphere is so high that the sun’s gravity cannot hold on to it. The plasma streams off of the sun in all directions at speeds of about 400 kilometers per second (about 1 million miles per hour). This is known as the solar wind.
The speed of the solar wind fluctuates, and carries with it magnetic clouds. These magnetic clouds are interacting regions where high-speed wind catches up with slow-speed wind. The solar wind speed is high (on average 800 kilometers per second) over coronal holes and low (300 kilometers per second) over streamers. These high- and low-speed streams interact with each other and alternately pass by the Earth as the sun rotates. These wind speed variations buffet
