/diy/ - Do It Yourself

>>1809968
Earth's orbit around the Sun is almost circular (eccentricity 0.017). The relative change of its orbital velocity (29..30 km/s) is about 3%. The changing Earth–Sun distance (152e6..147e6 km) results in an _increase_ of about 7% in total insolation at perihelion (Northern winter) relative to aphelion (Northern summer). UV radiation is what activates the ionosphere. The difference is minuscule compared to the effect of the solar cycles. Regarding HF propagation during the current minimum all we can pray for is an optimally disturbed ionosphere with lots of sporadic E events.