This session was definitely better at my station with numerous reports closer to local sunset than recently observed and consistency through the night. QRN was moderate overnight but this morning it seemed louder, at least in the direction that the receive antenna was pointed, probably ahead of storms that will be in the area around midday.
Geomagnetic activity was quiet and the Bz was at unity or slightly pointing to the South. Solar wind velocities average 330 km/s. DST is beginning to rebound after recent activity:
Phil, VE3CIQ, reports that conditions were not too bad overnight as he operated WSPR at 50-watt TPO. Phil decoded VE3EFF, WG2XIQ, WG2XKA and he was decoded by SWL/K9, WA3TTS, WE2XGR/3, WG2XKA, and WI2XFI.
John, WA3ETD / WG2XKA, returns for a complete session and offered this report:
“Following an extended period of daily thunderstorms, WG2XKA managed a full session of operation. Midsummer conditions persist with very high noise levels; however, WG2XIQ and WH2XGP were spotted here. XKA was spotted by seven ‘locals’. Need winter!”
Mike, WA3TTS, reports that his station took a lightning strike on Sunday night but only a few items were impacted. Mike attributes his station’s survival to the significant improvements that he has made with his electrical service ground.
Steve, VE7SL, reports that he decoded five WSPR stations and was decoded by seven unique stations with WH2XCR providing seventeen decodes. There were no reports from eastern stations.
Larry, W7IUV / WH2XGP, reports a very high noise level in Washington state but he managed to decoded five WSPR stations and was decoded by eleven unique stations including WG2XKA in Vermont.
Neil, W0YSE/7 / WG2XSV, provided the following comments and statistics:
Regional and continental WSPR breakdowns:
There were no reports from the Caribbean, trans-Atlantic, trans-African, or trans-Equatorial paths.
Laurence, KL7L / WE2XPQ, reports poor conditions, decoding only VE7SL and WH2XCR:
Merv, K9FD/KH6 / WH2XCR, generally experienced a typical session although the path to Australia was not quite as good as seen recently. There is lightning between Australia and New Zealand and this may be contributing to the lack or reports.
Jim, W5EST, presents “PART 3: GMF STORMS ON OUR E & F THEORY JUNGLE SAFARI”:
“Parts 1 and 2 suggested that theory based on the Appleton-Hartree equation (AHL, magneto-ionic theory) puts 630m receiving antennas and techniques in the limelight on 630m. I’ve discussed a process of reflection by an ionospheric region in which geomagnetic field GMF is present, including O/X waves on E/W mid-latitude paths, and mentioned right/left circularly polarized waves on N/S mid-latitude paths.
As you know, the ionosphere isn’t just some feathery layers. It’s like a big old clock with lots of moving parts that works well sometimes, gets “dusty” and doesn’t work sometimes, and winds up from the outside. See the ionosphere/magnetosphere 4th visual at http://www.dailymail.co.uk/sciencetech/article-3135080/Earth-s-protective-shied-weakening-Trio-Swarm-satellites-set-reveal-fast-planet-s-magnetic-field-fading.html
For real-time graphs and reference info on space weather, see http://www.solarham.net/ and read and click on the numerous items. A 6 meter ionosphere article (2000) by J. R. Kennedy K6MIO/KH6 offers thought-provoking propagation ideas. http://www.uksmg.org/content/f2propagationmech.htm (Figures 2 and 5.)
What are geomagnetic storms, GMF storms for short? They involve space weather effects on the GMF and the consequences. Start out by carefully reading Bob Brown NM7M’s article http://www.astrosurf.com/luxorion/qsl-hf-tutorial-nm7m7.htm . See how he weaves together a ray tracing visual of O/X waves, polarization, and his discussion of GMF storms.
NM7M’s discussion underlies several reasons why your KB5NJD blog regularly reports on GMF and space weather info, like the following:
–Kp index (planetary K index) of GMF fluctuation. https://en.wikipedia.org/wiki/K-index
–Solar wind speed http://www.swpc.noaa.gov/phenomena/solar-wind and CMEs (coronal mass ejections) https://en.wikipedia.org/wiki/Coronal_mass_ejection . They alter and deform GMF lines and intensity as if compressing a GMF “balloon.”
—Bz, the N/S component of the interplanetary magnetic field https://www.spaceweatherlive.com/en/help/the-interplanetary-magnetic-field-imf
But how important are these considerations to propagation at 630m in mid-latitudes? One brief answer: We don’t know. Let’s find out! That’s a big reason why hams around the world, USA Part 5 experimenters, and 630m RX-only US hams take intense interest in this band. If you’re new to whole different radio world from HF—get active and join us!
Meanwhile, let me recite some background GMF information today.
GMF events mean significant variation in the GMF strength and/or direction. How much variation is that? First, let’s start with GMF strength itself.
GMF strength is measured in microTeslas. What’s a microTesla? For every microTesla of GMF, an electron traveling at speeds characteristic of the ionosphere will be pulled around in a loop, as if it were a hand of an ice skater spinning on ice, 28,000 times a second (28KHz/uT). At 50uT GMF an electron gyrates–executes such loops–1.4 million times a second (1.4 MHz, the gyrofrequency).
Think of microTeslas another way. You can see the force of GMF in your location on a magnetic compass needle. GMF gently pushes the needle to align with the GMF direction, but to an electron, GMF force is a colossus. And there’s more to say. The force of GMF on speeding electrons is not an aligning force, but weirdly pushes perpendicular to their direction of motion and perpendicular to the GMF direction as well.
Now it’s time to take a global tour of GMF. GMF droops to 30-35uT (microTeslas) at Hawaii and around the equator, where GMF is directed mostly horizontal and northward. As you go from southern EU to Scandinavia, 45uT rises to 50uT, and GMF inclination downward gets more pronounced.
50uT describes Texas and N. California. As you go from S. California to British Columbia, the GMF numbers rise from 47uT to 54uT. Anchorage, Alaska, environment offers 56uT, with inclination steeply downward.
In Australia, GMF rises from 50uT to 60uT going south from Brisbane to Melbourne. GMF inclines more steeply upward along the way. https://www.ngdc.noaa.gov/geomag/WMM/DoDWMM.shtml (click total intensity map).
K indices don’t tell GMF strength. Instead, they report how much GMF fluctuation occurs. They regularly tell how unsteady or unstable GMF is, during each 3 hours of day and night. Even a very strong GMF storm can involve less than one microTesla (< 1 uT) of GMF fluctuation. Reporting stations measure “…maximum fluctuations of horizontal components observed on a magnetometer during a three-hour interval.” https://en.wikipedia.org/wiki/K-index Subscript “p” after an index indicates a planetary average, as in Kp and Ap.
USA’s NOAA provides respective severity indices R, S, G from modest “1” to intense “5” to inform the public about radio blackouts, solar radiation, and geomagnetic storms. http://www.swpc.noaa.gov/noaa-scales-explanation
Plainly, this <1 uT level of fluctuation is quite small compared to the GMF itself. The GMF at 30-60 uT together with electron concentration levels in an ionospheric region provides the causal environment for 630m Faraday rotation and making 630m O/X waves.
So why do we care about 0.1 to 1.0 uT GMF fluctuations, say? One reason is that GMF fluctuations (even if modest as measured at ground level) can temporarily remove ionization from the F-region, disrupting HF propagation. GMF fluctuations can even reach the E-region, which we can expect would affect 630m, but more occasionally. If 630m is less affected less often than HF, then 630m can be a more reliable medium and even contribute a useful emergency preparedness band to hams’ overall emcomm capabilities.
Steady GMF doesn’t induce a voltage. Only a fluctuating magnetic field can induce voltages, and they can be disruptive in communication systems. Moreover, a GMF storm can disrupt protective relaying and even DC-saturate transformers in AC electric power grids. DC millivolts=GMF fluct.(microTeslas/sec) x AC transm. line length (km) x line height (m).
Such DC saturating current enables the AC grid to destroy its own transformers, as has occasionally and notably occurred. Refer to NM7M above and to: https://en.wikipedia.org/wiki/Geomagnetic_storm . http://www.solarsystemcentral.com/solar_storm_page.html
Stay tuned for more theory jungle safari!”
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD gmail dot (com)!