PROPAGATION
A Quick Look at Current Cycle 24 Conditions
(Data rounded to nearest whole number)
Sunspots:
Observed Monthly, January 2020: 4
12-month smoothed, July 2019: 2
10.7-cm Flux:
Observed Monthly, January 2020: 72
12-month smoothed, July 2019: 70
Ap Index:
Observed Monthly, January 2020: 5
12-month smoothed, July 2019: 6
One Year Ago: A Quick Look at Solar Cycle Conditions
(Data rounded to nearest whole number)
Sunspots:
Observed Monthly, January 2019: 4
12-month smoothed, July 2018: 13
10.7-cm Flux:
Observed Monthly, January 2019: 70
12-month smoothed, July 2018: 77
Ap Index:
Observed Monthly, January 2019: 6
12-month smoothed, July 2018: 11
This month, we’re looking at a phenomenon that occurs in the sky, in a layer of Earth’s atmosphere once called the Kennelly-Heaviside Layer. This layer extends from about 56 miles to about 65 miles above the Earth’s surface, and is now known as the E region of the ionosphere.
The air in this region is considerably thinner than the air below it (closer to Earth). As a result of this thin air, there are fewer collisions of ions and electrons, resulting in populations of molecular ions. The region is highly variable due to these ions absorbing soft X-rays, which in turn change the ionization in the layer — sometimes in very drastic levels from nighttime to daytime.
One of the significant attributes of the E region of interest to the radio amateur is that it’s also the region that interacts with solar plasma in a way that can be visually stunning, as well as in a way that can provide a unique mode of propagation. This phenomenon is known as the aurora.
What is the Aurora?
Aurora is a direct result of solar plasma interacting with
