The sunspot numbers have not been good, and it does not seem they’ll be getting much better anytime soon. According to the April 6 “K7RA Solar Update,” only 2 days of the March 29 – April 4 reporting week saw sunspots, and that was at the bare minimum. No sunspots showed at all for the previous reporting week. Solar flux has been sitting in the 60s lately and are forecast to remain at that level for the next 45 days. Better days lie ahead — eventually. Top contester Frank Donovan, W3LPL, asserts that solar precursors like spotless days, which correlate physical solar phenomena with future solar activity levels, are much better indicators of progress toward a solar minimum — a broad phase of the solar cycle — than of a specific event, such as the bottom of a broad solar minimum. Not only that, these and other solar precursors are useful in predicting the likely strength of Cycle 25, although accurate predictions of the strength and timeframe of the Cycle 25 solar maximum aren’t possible until the new sunspot cycle is under way.
“We entered the Cycle 24 solar minimum with the onset of 8 spotless days in June 2016,” Donovan pointed out. “We had only 32 spotless days in 2016. We had 15 spotless days in a row in March 2017, followed by relatively infrequent spotless days for the next 7 months.”
The frequency of spotless days accelerated in early November 2017, with 13 spotless days in a row. That was followed by many more spotless days over the next 5 months. In all, 2017 experienced 104 spotless days.
“The frequency of spotless days accelerated again last month, when we had 25 spotless days,” Donovan noted. “We’ve already had 54 spotless days during the first quarter of 2018. This data and comparisons to frequent spotless days during the last solar minimum suggests that we may have just begun a period of very frequent spotless days for approximately the next 2 years, similar to the period of September 2007 through January 2009.
Donovan said the next solar precursor is frequent extended periods of spotless days. For example, 2016 saw 14 spotless days in a row, March 2017 had 15, November 2017 saw 13, and early March experienced 14.
“Long periods of spotless days will become even more frequent as we go deeper into solar minimum,” Donovan predicted. Once extended periods of spotless days become more frequent, another solar precursor will become important, he said.
“New high-latitude, opposite-polarity Cycle 25 sunspots will then begin to appear more frequently, perhaps by late next year,” Donovan said. “More frequent Cycle 25 sunspots will signal that we’re approaching the bottom of the [Cycle 24] solar minimum phase.”
An ongoing solar precursor that could herald the future strength of Cycle 25 is the intensity of the solar polar magnetic fields prior to the Cycle 24 solar minimum, Donovan said. “The good news is that the solar polar magnetic field strength is already slightly stronger than it was prior to the last solar minimum,” he said. “This suggests that Cycle 25 will be somewhat stronger than Cycle 24.”
Donovan said if the long periods of spotless days end in about a year, that will be a precursor of a stronger Cycle 25. If they take more than 2 years to end, however, it will portend a weaker Cycle 25.
This chart shows the number of spotless days — in red — since the 10th spotless day of the onset of solar minimum in July 2016. In blue are the average numbers of spotless days during sunspot minimums following weak sunspot cycles similar to Cycle 24.
Source:ARRL
Review
Review of MFJ’s New Xiegu X5105 HF QRP Deluxo
Review of MFJ’s newest radio. MFJ is the sole importer of the new Xiegu X5105 160m-6m QRP SSB/CW/AM/FM radio with built in rechargeable battery... Read more
Is Ham Radio Dead? Is Ham Radio Doomed?
“Lots of speculation and knee-jerk reactions exist on social media about whether or not Ham Radio is Dead. I wonder what the statistics say? Let... Read more
A Review of the Power Genius XL – By Mack McCormick, W4AX
Power Genius XL Searching for the highest performing solid state linear amplifier on the market today? If so, then the Power Genius XL (PGXL) amplifie... Read more
How to measure current
It is often necessary to know how to measure current using a multimeter. Current measurements are easy to make, but they are done in a slightly... Read more
Review of CW Morse Paddles with weighted base
“CW Morse (cwmorse.us) makes a variety of inexpensive, 3D-printed Morse code keys. They’ve now added paddles for iambic keyers to their li... Read more
Antenna
10 $ WIFI 16dBi Super Antenna Pictorial
“In this pictorial I’m showing you how to make a 16dBi very powerful wifi antenna for under 10 dollars. I’ve already posted a movie... Read more
Optibeam OB8-4M 8 Element 4 Band
The OB8-4M is an extremely effective, compact and innovative Yagi for the classical four bands 40, 20, 15 and 10m. It is the first trapless Yagi for t... Read more
MIDI LOOP – 3,5 a 14,5 MHz
See More: Link Read more
DCU-3 Programmable Rotator Controller
DCU-3 Programmable Rotator Controller6 Programmable memories; Point & shoot and manual control!DCU-3 Digital Controllers feature six presets for... Read more
DIAMOND HF MOBILE “CL” SERIES ANTENNAS
The Diamond HF Mobile “CL” Series Antennas are a bit special. Centre Loafing is claomed to be superior to base loafing. Peter G3OJV, tests... Read more
App - Mobile
Introducing the Icom ST-4002A GPS tool for Android OS Devices
Automatically input GPS location data from an Android™ device to the transceiver. Compatible with IC-7100, IC-9100, IC-9700, ID-4100A/E, and ID-5100A/... Read more
xCluster: A Mac DXCluster Map App
xCluster is a visual display of dx cluster activity. DX spots are received via telnet or web services and displayed in a tabular form and plotted on a... Read more
RFinder – The World Wide Repeater Directory now free trial on Android!
In order to support the proliferation of third party app stores worldwide, we have now released RFinder on Android as trialware! Just go download it f... Read more
Tutorial – Using the new routing function in RT Systems featuring RFinder
Once again RFinder and RT Systems have partnered to kick radio programming up a notch. This tutorial will show you how to get the most o... Read more
What is Echolink? Ham Radio 2.0: Episode 56
Mark Goodrum, W5MHG, discusses Echolink for Ham Radio at the Duke City Hamfest Read more
Equipment
Portable QRP Ham Radio & PowerFilm Lightsaver Max
https://www.youtube.com/watch?v=3G0GxVuReLg Read more
LNR FX-4A QRP HF Transceiver
QRP HF Transceiver LNR is pleased to announce the FX-4a. This unit replaces the original FX-4 that we introduced in 2013. The original FX-4 was an exc... Read more
New RigExpert Green ZOOM Family of the antenna & cable analyzers
“New RigExpert Green ZOOM Family of the antenna & cable analyzers Dear RigExpert Followers, We are glad to present you a New RigExpert Green... Read more
Yaesu FT-950 HF+6 TRANSCEIVER
Yaesu FT-950 HF+6 TRANSCEIVER The FT-950, the newest radio in the direct lineage of the FTDX-9000 and FT-2000 series radios, has been developed to fi... Read more
Yaesu M-70 | Desktop Microphone
The Yaesu M-70 is a new desk top microphone from Yaesu, it is ideal for the new FT-DX10 model but will function with other Yaesu Models. More info so... Read more