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With Solar Minimum right around the corner, sunspot counts are at an almost 10-year low. So it came as a surprise yesterday when a relatively large sunspot emerged near the sun’s eastern limb.
AR2699 has a primary dark core larger than Earth with many smaller magnetic condensations trailing behind it, in all stretching more than 75,000 km across the sun’s surface.
Rare “solar minimum sunspots” are capable of intense explosions just like sunspots during more active phases of the solar cycle.
Many thanks to SWLing Post contributor, Michael Guerin, who shares this article at CNN by Dr. Don Lincoln, a senior physicist at Fermilab and researcher at the Large Hadron Collider:
Earth dodges a cosmic bullet — for now
Solar flares and related phenomena could cause tremendous damage to the Earth’s electric grids, writes Don Lincoln Read the full story
(CNN) Mother Nature has had a hectic past couple of weeks of hurricanes, an earthquake, wildfires and flooding. But while our attention has been turned to these humanitarian crises, Earth ducked a cosmic bullet the likes of which could have crippled human technological civilization.
Over the last week or so, the sun has experienced a series of solar flares, including the most energetic one in a decade. A solar flare occurs when magnetic energy in the vicinity of a sunspot is released, resulting in a bright spot on the sun that takes place over a time scale of perhaps 10 minutes — or even less.
[…]While solar flares can interfere with satellites, an even more dangerous phenomenon is called a coronal mass ejection (or CME). CMEs often accompany a flare and occur when some of the sun’s highly ionized material is ejected into space. Because a CME consists of matter and not the electromagnetic radiation of a flare, it can take a day or even more to travel from the sun to the Earth. Indeed, last week’s flares were accompanied by a CME, but it didn’t hit the Earth with its full fury.
If a CME happens to be aimed directly at Earth, the ionized particles can slam into the magnetic field that surrounds the Earth and distort its shape, a process called a geomagnetic storm. That’s when things can get dangerous. Moving magnetic fields can induce electrical currents on the Earth’s surface and damage equipment.
In 1989, a CME hit the Earth and knocked out power in Quebec and the northeast United States for nine hours. And in 1859, an enormous CME hit the Earth. Called the Carrington Event, after Richard Carrington, who observed and recorded it, this geomagnetic storm caused telegraph pylons and railroad rails to spark, shocked telegraph operators and was responsible for auroras visible at least as far south as Havana, Cuba, with some claims of auroras being observed near the Earth’s equator.
[…]A report by Lloyd’s of London in 2013 estimated that the damage to the US grid from a repeat of the Carrington Event would be in the range of $0.6-$2.3 trillion dollars and would require four to 10 years to repair.
“The total U.S. population at risk of extended power outage from a Carrington-level storm is between 20-40 million, with durations of 16 days to 1-2 years,” the Lloyd’s report said.[…]
Many thanks as well to Mike Hansgen (K8RAT) who also shares the latest space weather news from Tamitha Skov, reiterating how fortunate we were to miss this last barrage from our local star:
One additional note: I’m currently in the process of writing a lengthy article about how to protect your gear from an EMP (Electromagnetic Pulse) emanating from an event like this. In the past two weeks, I’ve had an uptick in inquiries about this, so I thought it best to consult an expert and produce a post. I’ll hopefully have this article published within a week or so. I’ll post it with the tag: EMP.
NOAA’s Space Weather Prediction Center (SWPC) has issued a strong (G3) geomagnetic storm watch for September 7 through September 9. The SWPC said the watch for September 7 remains in effect due to the arrival of a coronal mass ejection (CME) and the effects of a CME on September 4.
“Additionally, a G3 watch is now in effect for the 8 and 9 September UTC days in anticipation of the arrival of another CME associated with the X9.3 flare (R3 — strong radio blackout) on 6 September at 1202 UTC (0802 ET),” the SWPC said early on September 7. “Analysis indicates likely CME arrival late on 8 September into early 9 September.” The September 6 flare is being called the strongest in more than a decade.
Its effect on HF radio propagation has adversely affected the Hurricane Watch Net (HWN), currently operating on 20 and 40 meters as Hurricane Irma sweeps through the Caribbean.
As of September 7 at 1400 UTC, the solar flux index stood at 127, the sunspot number at 27, the A index at 11, and the K index at 4. All HF conditions are being deemed as no better than fair. The possibility of extended auroral displays could work to the benefit of VHF and UHF operators who aim their antennas north to take advantage of “buzz” mode. SWPC posts a 30-minute forecast of visible aurora.[…]
Also, check out Tamitha Skov’s forecast on YouTube:
Last night, I tested a couple of HF radios and all but the strongest shortwave broadcasters (WRMI, RHC) were wiped out. Even the strong stations sounded like weak DX. This is truly an HF blackout.
Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF), who recently shared one of Tamitha Skov’s space weather forecast videos.
Over the past few years, I’ve watched Dr. Skov’s weekly video forecasts to better understand the implications of incoming CMEs, solar winds, sun spots (or lack thereof) and geomagnetic storms. While her videos include a lot of technical details, they’re also much easier to understand than the typical propagation forecast. Plus, her videos they’re chock-full of solar imagery and animations.
This weekend, for example, we’re going to experience some disruptions to HF propagation. Yesterday, solar wind speed soared to 704–and at time of publishing this post it’s 721 km/sec (thanks for noting, Mike!).
Dr. Skov explains it all in her latest space weather video:
The Sun has likely already entered into a new unpredicted long-term phase of its evolution as a hydrogen-burning main sequence star — one characterized by magnetic sputtering indicative of a more quiescent middle-age. Or so say the authors of a new paper submitted to The Astrophysical Journal Letters.
Using observations of other sunlike stars made by NASA ’s Kepler Space Telescope, the team found that the Sun is currently in a special phase of its magnetic evolution.
At time of posting (June 28, 2016) the Sun has no Sun spots at all, which means very low solar activity. Credit: SDO/HMI (Click to enlarge)
Heretofore, the Sun was thought to have been just a more slowly rotating version of a normal yellow dwarf (G-spectral type) star. These results offer the first real confirmation that the Sun is in the process of crossing into its magnetic middle age, where its 11-year Sunspot cycles are likely to slowly disappear entirely. That is, from here on out, the Sun is likely to have fewer sunspots than during the first half of its estimated 10 billion year life as a hydrogen-burning star.
“The Sun’s 11-year sunspot cycle is likely to disappear entirely, not just get less pronounced; [since] other stars with similar rotation rates show no sunspot cycles,” Travis Metcalfe, the paper’s lead author and an astronomer at the Space Science Institute in Boulder, Colo., told me.[…]
Many thanks to SWLing Post contributor, Mike (K8RAT), who writes:
The Met Office has this brief introduction to the subject of space weather and the methods they use to make predictions. It may be useful to beginners in the radio hobby.
