Th ro w i n g O n e ’s Th o u g h t s A ro u n d t h e Wo rl d A talk about solar cycles, amateur radio, and you. By NW7US, Tomas Hood http://NW7US.us/ http://SunSpotWatch.com/ Space Weather Many ham radio operators don’t think much about space weather except when they can’t talk on their “usual” HF radio frequencies. Space Weather In the last few years, a lot more discussions about space weather have occurred, because the higher HF bands are dead. Space Weather Some speculate that we might see a mini-ice age! The thinking goes, “Without spots, solar energy will lead to global cooling. We’ve seen it before…” Space Weather Regarding Sunspot Cycle 24, everyone seems interested in where we are, and … Space Weather Regarding Sunspot Cycle 24, everyone seems interested in where we are, and … W H E N W I L L O U R H F BA N D S I M P R OV E ? Space Weather Why is space weather important to us? Where are we really, in Cycle 24? Space Weather Let’s start with a REFRESHER on Radio wave Propagation Space Weather and HF On the shortwave spectrum, or, high frequencies (HF), technically 3 MHz to 30 MHz… Space Weather and HF …we rely on the ionosphere to get our transmitted signal from our station antenna to the DX station’s antenna. Space Weather and HF The ionosphere can reflect (refract) an HF signal, if the ionosphere is sufficiently energized. Space Weather and HF The more solar energy energizing the ionosphere, the higher the frequency that we can “propagate” via this “reflector.” Space Weather and HF During the day, if there is too much energy, HF radio signals may be absorbed by the entire ionosphere, but... Space Weather and HF …during the day, at least the lowest HF radio signals are absorbed by the D-region (the lowest ionospheric layer. Space Weather and HF During the night, the D-region nearly disappears, allowing lower frequencies to reach the F-Region and propagate. Space Weather and HF Throughout the day, whatever radio signal reaches the ionosphere, if the F-Region is “strong enough,” it will refract that signal. Space Weather and HF It is clear that the influence of solar energy directly affects how strongly our radio transmission will be received at the DX station. Space Weather and HF Sunspot activity is a good indicator of the overall “energy level” of the Sun, as it relates to HF radio propagation via the ionosphere. Space Weather and HF Sunspot activity is a good indicator of the overall “energy level” of the Sun, as it relates to HF radio propagation via the ionosphere. Space Weather and HF Another measurement that is useful is the “radio noise” at 2800 MHz, or, at 10.7 cm, the 10.7-cm Radio Flux Index. Space Weather and HF Generally speaking, with “high” indices, the higher the frequencies that will propagate via the ionosphere. Space Weather and HF However, there are solar “events” that can degrade HF communications. Space Weather and HF Solar Flares can disrupt HF communications. Space Weather and HF Coronal Holes can also degrade our HF communications. Space Weather and HF A Coronal Mass Ejection also disrupts global HF communications. Space Weather and HF Being aware, or better, being able to predict space weather makes sense. Space Weather and HF Being aware, or better, being able to predict space weather makes sense. Better planning of our time Space Weather and HF Being aware, or better, being able to predict space weather makes sense. Better planning of our time Understanding current conditions Space Weather and HF Being aware, or better, being able to predict space weather makes sense. Better planning of our time Understanding current conditions Working around conditions. Where are we in Cycle 24? Let’s look at the transition between Sunspot Cycle 23 and Cycle 24. Where are we in Cycle 24? The general consensus is that the last Sunspot Cycle Minimum started in 2006 (Cycles 23-24) Where are we in Cycle 24? It looks as if the NEW minimum (the end of Cycle 24) may be here, now. Where are we in Cycle 24? The overall sunspot minimum between Cycle 23 and Cycle 24 lasted ~ three years. That was longer than the previous few. Where are we in Cycle 24? What did we learn during that prolonged minimum “quiet” period? Where are we in Cycle 24? What did we learn during this prolonged minimum “quiet” period? Sporadic-E (10 & 6 meters) more intense. Where are we in Cycle 24? What did we learn during this prolonged minimum “quiet” period? Sporadic-E (10 & 6 meters) more intense. World-wide DX is possible on lower bands. Where are we in Cycle 24? What did we learn during this prolonged minimum “quiet” period? Sporadic-E (10 & 6 meters) more intense. World-wide DX is possible on lower bands. Where are we in Cycle 24? What did we learn during this prolonged minimum “quiet” period? Sporadic-E (10 & 6 meters) more intense. World-wide DX is possible on lower bands. QRP works the world, too (JT65A, FT8, CW). Where are we in Cycle 25? The NEW question on many minds: Will the new cycle (Cycle 25) be a weak, typical (moderate), or very strong cycle? Where are we in Cycle 25? Most solar scientists predict a WEAK cycle. Where are we in Cycle 25? The NOAA/NASA co-chaired an international panel to forecast Solar Cycle 25. That panel released a preliminary forecast for Solar Cycle 25 on April 5, 2019. Where are we in Cycle 25? The consensus: Cycle 25 will be similar in size to Cycle 24. It is expected that sunspot maximum will occur no earlier than the year 2023 and no later than 2026 with a minimum peak sunspot number of 95 and a maximum peak sunspot number of 130. Where are we in Cycle 25? In addition, the panel expects the end of Cycle 24 and start of Cycle 25 to occur no earlier than July, 2019, and no later than September, 2020. The panel hopes to release a final, detailed forecast for Cycle 25 by the end of 2019. Where are we in Cycle 25? Could we see a stronger-than-predicted cycle? Sunspot Cycle 19 was big! Where are we in Cycle 25? Cycle 19 started LOWER than cycles that were WEAK. Could Cycle 25 start slowly, but rise fast, translating to a STRONG cycle? Where are we in Cycle 25? Of course, because we have no good model and we’re just starting to understand our Sun, we won’t know until it happens… Where are we in Cycle 24? Of course, because we have no good model and we’re just starting to understand our Sun, we won’t know until it happens… We can celebrate, though, the obvious start we’re seeing in the new cycle. Where are we in Cycle 25? The rest of this year will be filled with LOW activity. But, if we are at solar cycle minimum (and we are), we COULD see an uptick in sunspot activity at any time, going forward! Where are we in Cycle 24? The rest of this year could be filled with activity: Increase in daily sunspot activity. Where are we in Cycle 24? The rest of this year could be filled with activity: Increase in daily sunspot activity. Increase in solar flares. Where are we in Cycle 24? The rest of this year could be filled with activity: Increase in daily sunspot activity. Increase in solar flares. Increase in geomagnetic storms. Where are we in Cycle 24? The rest of this year could be filled with activity: But, certainly, an increase in DX… Where are we in Cycle 24? The rest of this year could be filled with activity: But, certainly, an increase in DX And a wider variation in conditions. Space Weather and You Increase your understanding of space weather & radio propagation: Read my propagation columns in CQ Communications, and Popular Communications. Space Weather and You Join the Facebook Space Weather and Radio Propagation Resource Page: https://Facebook.com/spacewx.hfradio Space Weather and You Join the YouTube Space Weather and Radio Propagation Resource Channel: https://YouTube.com/NW7US Space Weather and You Join the YouTube Space Weather and Radio Propagation Resource Channel: https://YouTube.com/NW7US
