Useful information about Propagation:
DXing.info - conditions having influence on reception of MW stations.
Wikipedia - how radiowaves are propagated.
NOAA - Space Weather, weekly
PROPAGATION de K7RA
It has been quite a week for dramatic solar activity. The average daily sunspot number was up nearly 26 points to 69.4, and average daily solar flux rose nearly 17 points to 121.9 for the period March 1-7...
Full report here: http://www.arrl.org/
Mike Terry, dxld yg (11/3-2012)
STRONGEST SOLAR STORM SINCE 2005 HITTING EARTH
The sun is bombarding Earth with radiation from the biggest solar storm in more than six years with more to come from the fast-moving eruption.
The solar flare occurred at about 11 p.m. EST Sunday and will hit Earth with three different effects at three different times. The biggest issue is radiation, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center in Colorado.
The radiation is mostly a concern for satellite disruptions and astronauts in space. It can cause communication problems for polar-traveling airplanes, said space weather center physicist Doug Biesecker.
Radiation from Sunday's flare arrived at Earth an hour later and will likely continue through Wednesday. Levels are considered strong but other storms have been more severe. There are two higher levels of radiation on NOAA's storm scale — severe and extreme — Biesecker said. Still, this storm is the strongest for radiation since May 2005.
The radiation — in the form of protons — came flying out of the sun at 93 million miles per hour.
"The whole volume of space between here and Jupiter is just filled with protons and you just don't get rid of them like that," Biesecker said. That's why the effects will stick around for a couple days.
NASA's flight surgeons and solar experts examined the solar flare's expected effects and decided that the six astronauts on the International Space Station do not have to do anything to protect themselves from the radiation, spokesman Rob Navias said.
A solar eruption is followed by a one-two-three punch, said Antti Pulkkinen, a physicist at NASA's Goddard Space Flight Center in Maryland and Catholic University.
First comes electromagnetic radiation, followed by radiation in the form of protons.
Then, finally the coronal mass ejection — that's the plasma from the sun itself — hits. Usually that travels at about 1 or 2 million miles per hour, but this storm is particularly speedy and is shooting out at 4 million miles per hour, Biesecker said.
It's the plasma that causes much of the noticeable problems on Earth, such as electrical grid outages. In 1989, a solar storm caused a massive blackout in Quebec. It can also pull the northern lights further south.
But this coronal mass ejection seems likely to be only moderate, with a chance
for becoming strong, Biesecker said. The worst of the storm is likely to go
north of Earth.
And unlike last October, when a freak solar storm caused auroras to be seen as far south as Alabama, the northern lights aren't likely to dip too far south this time, Biesecker said. Parts of New England, upstate New York, northern Michigan, Montana and the Pacific Northwest could see an aurora but not until Tuesday evening, he said.
For the past several years the sun had been quiet, almost too quiet. Part of that was the normal calm part of the sun's 11-year cycle of activity. Last year, scientists started to speculate that the sun was going into an unusually quiet cycle that seems to happen maybe once a century or so.
Now that super-quiet cycle doesn't seem as likely, Biesecker said.
Scientists watching the sun with a new NASA satellite launched in 2010 — during the sun's quiet period — are excited.
"We haven't had anything like this for a number of years," Pulkkinen said. "It's kind of special."
NOAA's Space Weather Prediction Center: http://www.swpc.noaa.gov/
NASA's Solar Dynamics Observatory: http://sdo.gsfc.nasa.gov/
Associated Press, Washington via Mike Terry, dxld yg (24/1-2012)
LARGE SOLAR FLARE
Here is video of a very very large solar flare on the way to earth
Today's M2.6-class Solar Flare produced a nice Coronal Mass Ejection, which appears to be Earth directed. Current forecasts have it to arrive on January 21, 2012 at approx. 22:30 UT (let's give or take 7 hours... it's over 90 million mile journey after all).
Our friends at the NASA Goddard Space Weather Lab are predicting possible strong geomagnetic storms. What will it mean for us? Possibly some Aurorea and perhaps some communications interruption. No major issues are expected.
A view of the Active Regions 1401 and 1402 over the past couple of days shows the development of those beautiful sunspots. Then two views of the solar flare through the SDO instrument before concluding with views from STEREO Ahead and Behind.
Credit: NASA SDO & NASA STEREO (21/1) via Kevin Redding on ABDX via Mike Terry, dxld yg (22/1-2012)
dropped this week, with average daily sunspot numbers declining over 39 points to 94.7. It's been 13 weeks since the average daily sunspot number for the week was that low or lower...
More at http://www.spaceweather.com
Mike Terry via dxld yg (18/12-2011)
Space Weather News
One of the biggest sunspot groups in many years has just emerged over the sun's eastern limb. The sunspot's magnetic canopy is crackling with M-class (medium-sized) solar flares and seems poised to launch even stronger X-class eruptions. The sunspot, named AR1339, is not yet directly facing Earth but it will be turning toward our planet in the days ahead. Check http://spaceweather.com for images of the behemoth and updates.
Read more at http://spaceweather.com
Mike Terry, dxld yg (3/11-2011)
Sunspot 1302 unleashed towards Earth.
Greenbelt - Scientists are monitoring a sunspot that produced an X1.9-category solar storm that was unleashed over the weekend and could be headed towards Earth. Sunspot 1302 is so strong that it has been detected shortwave radio on this planet.
Digital Journal has reported in the past on intense solar storms, and so far nothing catastrophic has occurred. The worst thing that has transpired thus far has been loss of radio signals in some parts of the United States.
On Monday, NASA issued a news release that updated us on a strong X1.9-category solar storm that erupted from active region (sunspot) 1302 Saturday morning that was recorded by the space administration’s Solar Dynamics Observatory.
The published video presented viewers with a shadowy shock rave that moved away from the impact site. This has led scientists to believe that the blast produced a coronal mass ejection (CME) that could hurt our magnetic field this week.
Although none of the blasts were directed towards the Earth, the sunspot will turn toward us within the next few days. NASA officials say that AR1302 is continuing to grow and that there is no evidence that it will quiet down anytime soon. It is in a position to produce more CMEs.
The Goddard Space Weather Lab detected solar wind plasma sneaking into the geosynchronous orbit that could affect satellites because they will experience solar wind plasma and magnetic fields.
As the sunspot continues to produce intense solar storms, audio has been recorded of the solar event. Thomas Ashcraft in New Mexico was able to record the sounds of the activity on his shortwave radio.
Sky gazers in high-latitude areas should look out for auroras come nightfall.
Continuity Central also issued a news release for businesses. It noted NASA’s list of possible impact by space weather. It reiterated NASA’s warning that intense solar activity could cause blackouts across the globe and could last for months as engineers attempt to repair the situation.
This would lead to the disruption of commerce since numerous institutions would be offline, airplanes would not be able to utilize GPS navigation and there would be no power for hundreds of millions of people.
Read more: http://digitaljournal.com/article/312033#ixzz1ZGJRTy8l
Digital Journal by Andrew Moran via Mike Terry, dxld yg (28/9-2011)
A strong geomagnetic storm is in progress following the impact of a coronal mass ejection (CME) today, Sept. 26th, at approximately 12:15 UT. Analysts at the Goddard Space Weather Lab report a "strong compression of Earth's magnetosphere" and the possibility that satellites in geosynchronous orbit have been exposed to solar wind plasma and magnetic fields. Mid- to high-latitude sky watchers should be alert for auroras after nightfall. Observing tip: The hours around local midnight are usually best for spotting Northern and Southern Lights. Check http://spaceweather.com for images and updates...
http://spaceweather.com via Mike Terry, dxld yg (26/9-2011)
PROPAGATION from K7RA
Solar indicators rose again this week, with average daily sunspot numbers increasing nearly 21 points to 104.3, and average daily solar flux up nearly 12 points to 115.5. Geomagnetic numbers were up as well, with the most active geomagnetic day occurring on September 3...
Mike Terry, dxld yg (12/9-2011)
GEOMAG STORMS, BLACKOUTS, AURORAE
Geophysical Alert Message.
Solar-terrestrial indices for 09 September follow.
Solar flux 112 and mid-latitude A-index 24.
The mid-latitude K-index at 0300 UTC on 10 September was 5 (78 nT).
Space weather for the past 24 hours has been moderate.
Geomagnetic storms reaching the G2 level occurred.
Radio blackouts reaching the R1 level occurred.
Space weather for the next 24 hours is predicted to be minor.
Geomagnetic storms reaching the G1 level are likely.
Radio blackouts reaching the R1 level are likely.
Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
WWV via DXLD yg (10/9-2011)
See http://www.spaceweather.com for aurora reports, photos, current auroral oval map --- as usual, looks too far north of Oklahoma
Glenn Hauser, dxld yg (10/9-2011)
The Sun is alive with sunspots, today.. this is very good for shortwave radio propagation.
Tomas David Hood
Mike Terry via dxld yg (31/7-2011)
BIG SUNSPOT NOTICE
After more than a week of quiet, solar activity is picking up with the emergence of two large sunspot groups on the sun's northeastern limb.
The active regions are crackling with C- and M-class solar flares. So far none of the eruptions has been squarely Earth directed, but that could change in the days ahead as solar rotation turns the sunspots to face our planet.
Visit http://spaceweather.com for images and more information.
Mike Terry via dxld yg (29/7-2011)
Emerging sunspot 1245 produced a series of strong shortwave radio bursts on July 7th. Tap here to listen to the sun's static-y roar.
More details at http://3d-sun.org/news/newsitem_31.html
Mike Terry via dxld yg (20/7-2011)
Magnificent Solar Flare on June 7th
MAGNIFICENT ERUPTION: This morning around 0641 UT, magnetic fields
above sunspot complex 1226-1227 became unstable and erupted. The blast
produced an M2-class solar flare, an S1-class radiation storm, and a massive CME. A recording of the blast from NASA's Solar Dynamics Observatory ranks as one of the most beautiful and dramatic movies of
the SDO era. Must-see movies at http://spaceweather.com
AURORA WATCH: High-latitude sky watchers in both hemispheres should be
alert for auroras during the late hours of June 8th or 9th when a CME from today's eruption could deliver a glancing blow to Earth's magnetic field. Aurora alerts are available from
http://spaceweatherphone.com (voice) or http://spaceweathertext.com (text).
Space Weather News for June 7, 2011 http://spaceweather.com via Mark Coady, Peterborough, ON K9J 6X3, ODXA yg via DXLD yg (8/6-2011)
'Dramatic' solar flare could disrupt Earth communications
An unusual solar flare observed by a NASA space observatory on Tuesday could cause some disruptions to satellite communications and power on Earth over the next day or so, officials said.
The potent blast from the Sun unleashed a firestorm of radiation on a level not witnessed since 2006, and will likely lead to moderate geomagnetic storm activity by Wednesday, according to the National Weather Service.
"This one was rather dramatic," said Bill Murtagh, program coordinator at the NWS's Space Weather Prediction Center, describing the M-2 (medium-sized) solar flare that peaked at 1:41 am Eastern time in the United States, or 0541 GMT.
"We saw the initial flare occurring and it wasn't that big but then the eruption associated with it -- we got energy particle radiation flowing in and we got a big coronal mass injection," he said.
"You can see all the materials blasting up from the Sun so it is quite fantastic to look at."
NASA's solar dynamics observatory, which launched last year and provided the high-definition pictures and video of the event, described it as "visually spectacular," but noted that since the eruption was not pointed directly at Earth, the effects were expected to remain "fairly small."
"The large cloud of particles mushroomed up and fell back down looking as if it covered an area of almost half the solar surface," said a NASA statement.
Murtagh said space weather analysts were watching closely to see whether the event would cause any collision of magnetic fields between the Sun and Earth, some 93 million miles (150 million kilometers) apart.
"Part of our job here is to monitor and determine whether it is Earth-directed because essentially that material that is blasting out is gas with magnetic field combined," he told AFP.
"In a day or so from now we are expecting some of that material to impact us here on Earth and create a geomagnetic storm," he said.
"We don't expect it to be any kind of a real severe one but it could be kind of a moderate level storm."
The Space Weather Prediction Center said the event is "expected to cause G1 (minor) to G2 (moderate) levels of geomagnetic storm activity tomorrow, June 8, beginning around 1800 GMT."
Any geomagnetic storm activity will likely be over within 12-24 hours.
"The Solar Radiation Storm includes a significant contribution of high energy protons, the first such occurrence of an event of that type since December 2006," the NWS said.
As many as 12 satellites and spacecraft are monitoring the heliosphere, and one instrument in particular on board NASA's lunar reconnaissance orbiter is measuring radiation and its effects.
"Certainly over the (two-year) lifetime of the mission this is the most significant event," said Harlan Spence, principal investigator for the cosmic ray telescope for the effects of radiation, or CRaTER.
"This is really exciting because ironically when we were developing the mission initially we thought we would be launching closer to a solar maximum when these big solar particle events typically occur," Spence told AFP.
"Instead we launched into a historic solar minimum that took a long, long time to wake up," he said.
"This is interesting and significant because it shows the Sun is returning to its more typical active state."
The resulting geomagnetic storm could cause some disruption in power grids, satellites that operate global positioning systems and other devices, and may lead to some rerouting of flights over the polar regions, Murtagh said.
"Generally it is not going to cause any big problems, it will just have to be managed," he said.
"If you fly from the United States to Asia, flying over the North Pole, there are well over a dozen flights every day," he added.
"During these big radiation storms some of these airlines will reroute the flights away from the polar regions for safety reasons to make sure they can maintain communications.
"People operating satellites would keep an eye on this, too, because geomagnetic storming can interfere with satellites in various ways whether it is the satellite itself or the signal coming down from the receiver."
The aurora borealis (Northern Lights) and aurora australis (Southern Lights) will also likely be visible in the late hours of June 8 or 9, NASA said.
AFP By Kerry Sheridan Jun 7, 2011 via dxld yg (8/6-2011)
:Product: Geophysical Alert Message wwv.txt
:Issued: 2011 Jun 08 0300 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Geophysical Alert Message
Solar-terrestrial indices for 07 June follow.
Solar flux 96 and mid-latitude A-index 8.
The mid-latitude K-index at 0300 UTC on 08 June was 4 (58 nT).
Space weather for the past 24 hours has been minor.
Solar radiation storms reaching the S1 level occurred.
Radio blackouts reaching the R1 level occurred.
Space weather for the next 24 hours is predicted to be moderate.
Solar radiation storms reaching the S2 level are likely.
WWV via dxld yg (8/6-2011)
PROPAGATION de K7RA
April 1, 2011
The activity we could see recently on our Sun’s far side -- thanks to the STEREO mission -- has been rotating into view, producing some nice sunspot activity and the resulting improved upper-HF propagation. Compared to the previous week (March 17-23), the past week (March 24-30) showed average daily sunspot numbers up more than 61 points to 102.1, while the average daily solar flux up nearly 20 points to 114.7. Geomagnetic conditions were quieter as well, and reports from readers show greatly improved propagation on 20, 15 and10 meters.
Sunspot numbers for March 24-30 were 73, 104, 104, 132, 103, 108 and 91, with a mean of 102.1. The 10.7 cm flux was 107.6, 112.6, 114.5, 115.6, 118.5, 116.2 and 117.6, with a mean of 114.7.
The estimated planetary A indices were 4, 3, 1, 2, 3, 4 and 5, with a mean of 3.1. The estimated mid-latitude A indices were 3, 2, 1, 2, 2, 2 and 4, with a mean of 2.3. This table shows a new sunspot group on March 23, two more groups appeared March 24, two more on March 25 and another two more on March 27.
The latest prediction from USAF/NOAA -- issued Thursday, March 31 -- differs from the one from the previous day. The March 30 prediction was referenced in The ARRL Letter, and the new prediction is less optimistic in terms of increasing solar activity...
Full story at http://www.arrl.org/news/the-k7ra-solar-update-158
Mike Terry, dxld yg (2/4-2011)
Solar Radiation Storms thru 21 Feb.
SPACE WEATHER ADVISORY OUTLOOK #11- 7
2011 February 15 at 9:38 a.m. MST (2011 February 15 1638 UTC)
**** SPACE WEATHER OUTLOOK ****
Summary For February 7-13
R2 (Moderate) Solar Radiation Storms were observed on 13 February.
Outlook For February 16-22
R1 (Minor) and R2 (Moderate), along with possible R3 (Strong) Solar
Radiation Storms are expected through 21 February.
Data used to provide space weather services are contributed by NOAA,
USAF, NASA, NSF, USGS, the International Space Environment Services
and other observatories, universities, and institutions. More
information is available at SWPC's Web site http://swpc.noaa.gov
Official Space Weather Advisory issued by NOAA Space Weather Prediction Center,
Boulder, Colorado, USA via dxld yg (15/2-2011)
A solar wind stream hit Earth's magnetic field during the late hours of Feb. 4th, sparking a G2-class (Kp=6) geomagnetic storm, in progress. High-latitude sky watchers should be alert for auroras, especially during the hours around local midnight. (from http://www.spaceweather.com via DXLD)
:Product: Geophysical Alert Message wwv.txt
:Issued: 2011 Feb 05 0300 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Geophysical Alert Message
Solar-terrestrial indices for 04 February follow.
Solar flux 82 and mid-latitude A-index 15.
The mid-latitude K-index at 0300 UTC on 05 February was 4 (41 nT).
Space weather for the past 24 hours has been minor.
Geomagnetic storms reaching the G1 level occurred.
Space weather for the next 24 hours is expected to be minor.
Geomagnetic storms reaching the G1 level are expected.
(SWPC via DXLD)
Unbelievable auroral conditions
Warm greetings ! Huge opening to South America including Andean pop music on 1070 AM badly jammed by WTIC-1080 Stalinist jammer, YVRQ and Cadena Agramonte fighting on 910 AM and several in the 800s including at least two Latins on 860 in null of aurora weakened CJBC-860 Toronto. One of them is LA Q, obviously not XEQ which is on 940.
May the good DX be with you! Conditions are way above average almost spectacular, something I haven`t seen since December of 2006
Bogdan Chiochiu, Pierrefonds or Montreal, PQ, 0209 UT February 5, HCDX via dxld yg (5/2-2011)
GOODBYE TO SUNSPOTS?
BDXC Propagation Report February 2011.
Hi Glenn [Hauser], Here is the February edition of the propagation report.
During January conditions have remained steady and February should remain the same with the Solar Flux mainly at 82. Apart from a slight fluctuation around 3rd February, the Boulder A index is likely to stay at 5 and the K index at 2. --- http://www.wm7d.net/hamradio/solar/27d_forecast.shtml
NASA Sun Spot Number predictions revised yet again:
NASA has revised their Sun Spot prediction once again and it is now at the level of the Maunder Minimum of 1675-1715 when the climate was much colder. The solar cycle 24 predicted sunspot maximum has been reduced again - predicted peak down to 59 Max. Current prediction for the next sunspot cycle maximum gives a smoothed sunspot number maximum of about 59 in June/July of 2013. We are currently two years into Cycle 24 and the predicted size continues to fall.
--- NASA Solar Physics, 3 January 2011.
Cycle 24 Continues:
"During the course of an approximate eleven year sunspot cycle, the minimum phase, or quiet sun, is generally considered to exist during the time when the smoothed sunspot number (SSN) drops, and remains below 30. The smoothed sunspot number is a monthly index compiled by the Royal Observatory of Belgium for measuring solar cycle progress.
An unbroken string of smoothed sunspot numbers has been recorded since 1750. The present period of quiet sun began as declining Cycle 23 dropped below the SSN 30 level during April, 2005. A period of moderate solar activity is expected for the remainder of 2011, reaching a sunspot count on the order of 60 by year's end. This six-year solar quiet period was the deepest and most persistent recorded in almost two hundred years. It mystified solar scientists, and it is another example of how little is yet known about sunspots and of the nature of the Sun itself." (George Jacobs, WRTH 2011)
Say Goodbye To Sunspots?
"Scientists studying sunspots for the past two decades have concluded that the magnetic field that triggers their formation has been steadily declining. If the current trend continues, by 2016 the sun's face may become spotless and remain that way for decades - a phenomenon that in the 17th century coincided with a prolonged period of cooling on Earth.
The last solar minimum should have ended last year, but something peculiar has been happening. Although solar minimums normally last about 16 months, the current one has stretched over 26 months-the longest in a century. One reason, according to a paper submitted to the International Astronomical Union Symposium No. 273, an online colloquium, is that the magnetic field strength of sunspots appears to be waning."
Sunspots may vanish by 2015. By William Livingston, and Matthew Penn:
"We have observed spectroscopic changes in temperature sensitive molecular lines, in the magnetic splitting of an Fe I line, and in the continuum brightness of over 1000 sunspot umbrae from 1990-2005. All three measurements show consistent trends in which the darkest parts of the sunspot umbra have become warmer (45K per year) and their magnetic field strengths have decreased (77 Gauss per year), independently of the normal 11-year sunspot cycle. A linear extrapolation of these trends suggests that few sunspots will be visible after 2015."
This article can be viewed in PDF format at:
Thanks to Ken Fletcher and Mike Terry for this month's articles. Links to these articles can be found at: http://www.jameswelsh.org.uk
Regards James Welsh, Jan 29, BDXC-UK via dxld yg (1/2-2011)
Space Weather and Radio Resources report that today we are just seeing the new sunspot region rotating into view.
HFRadio.org via Facebook December 1, 2010
I am advised that this will probably raise the Maximum Usable Frequency on most ionospheric shortwave paths of signal propagation. It is good for shortwave/high frequency radio.
Mike Terry via dxld yg (2/12-2010)
Propagation de K7RA
Average sunspot numbers for the week were up nearly 44 points to 55.6.
Average solar flux readings were unchanged, at 84.9. For a few days solar
flux values rose above 90, but currently the projection from USAF and NOAA
for solar flux over October 22-31 is 82, 82, 82, 82, 80, 80, 80, 80, 80 and
More at http://www.southgatearc.org/propagation/2010/k7ra/october_23.htm
Mike Terry, dxld yg (24/10-2010)
Massive solar storm to hit Earth in 2012 with 'force of 100m bombs'
Melbourne, Aug 26 (ANI): Astronomers are predicting that a massive solar storm, much bigger in potential than the one that caused spectacular light shows on Earth earlier this month, is to strike our planet in 2012 with a force of 100 million hydrogen bombs.
Several US media outlets have reported that NASA was warning the massive flare this month was just a precursor to a massive solar storm building that had the potential to wipe out the entire planet's power grid.
Despite its rebuttal, NASA's been watching out for this storm since 2006 and reports from the US this week claim the storms could hit on that most Hollywood of disaster dates - 2012.
Similar storms back in 1859 and 1921 caused worldwide chaos, wiping out telegraph wires on a massive scale. The 2012 storm has the potential to be even more disruptive.
"The general consensus among general astronomers (and certainly solar astronomers) is that this coming Solar maximum (2012 but possibly later into 2013) will be the most violent in 100 years," News.com.au quoted astronomy lecturer and columnist Dave Reneke as saying.
"A bold statement and one taken seriously by those it will affect most, namely airline companies, communications companies and anyone working with modern GPS systems.
"They can even trip circuit breakers and knock out orbiting satellites, as has already been done this year," added Reneke.
No one really knows what effect the 2012-2013 Solar Max will have on today's digital-reliant society.
Dr Richard Fisher, director of NASA's Heliophysics division, told Reneke the super storm would hit like "a bolt of lightning", causing catastrophic consequences for the world's health, emergency services and national security unless precautions are taken.
NASA said that a recent report by the National Academy of Sciences found that if a similar storm occurred today, it could cause "1 to 2 trillion dollars in damages to society's high-tech infrastructure and require four to 10 years for complete recovery".
The reason for the concern comes as the sun enters a phase known as Solar Cycle 24.
Most experts agree, although those who put the date of Solar Max in 2012 are getting the most press.
They claim satellites will be aged by 50 years, rendering GPS even more useless than ever, and the blast will have the equivalent energy of 100 million hydrogen bombs.
"We know it is coming but we don't know how bad it is going to be," Fisher told Reneke.
"Systems will just not work. The flares change the magnetic field on the Earth and it's rapid, just like a lightning bolt. That's the solar effect," he added.
The findings are published in the most recent issue of Australasian Science.
Brainman Media via dxld yg (30/8-2010)
The K7RA Solar Update
August 13, 2010
This week's bulletin is written by Tomas Hood, NW7US, who is filling in for
Tad Cook, K7RA.
Sunspot numbers and solar flux increased this week, with the average daily
sunspot numbers up more than 32 points to 53, and the average daily 10.7-cm
solar flux up more than 3 points to 84.5. These are the numbers from last
Thursday through this Wednesday, August 5 through August 11. The sunspot
count on August 11 was 66, consisting of four active sunspot regions: 1093,
1095, 1096, and 1097. The largest of these was 1093, with a relative size of
130 millionths of a solar hemisphere. The sunspot count of 66 is the highest
yet recorded in Solar Cycle 24. Another noteworthy development this week is
that five active sunspot regions were reported on August 12; however, most
of the spots were small, resulting in a daily sunspot count of 50.
Sunspot numbers for August 5-August 11were 54, 49, 47, 46, 53, 56 and 66,
with a mean of 53. The 10.7 cm flux was 82.7, 82.0, 90.5, 82.6, 84.1, 83.5
and 85.8, with a mean of 84.5. The estimated planetary A indices were 10, 8,
5, 4, 10, 8 and 10, with a mean of 7.9. The estimated mid-latitude A indices
were 7, 6, 4, 2, 7, 7 and 9, with a mean of 6.
While solar activity was higher this week, geomagnetic activity has been
quiet, with daily planetary A indices ranging from 4-10, and the daily
mid-latitude A indices ranging from 2-9. The predicted planetary A index for
August 13-14 is 5, then 8 on August 15, 12 on August 16, then 5 on August
17-21. NOAA/USAF expects geomagnetic activity to be mostly quiet for the
next week; a very small coronal hole is rotating across the solar disc, but
will have little if any influence on the geomagnetic activity this coming
Another newsworthy event was the M-class X-ray flare that erupted from
active sunspot region 1093 on August 7. This flare was 10 times more
powerful than the C-class flare on August 1 that caused so much news media
attention. This M1.0 magnitude solar flare peaked at 1824 UTC on August 7
and ejected a huge mass of coronal plasma. Many hoped that the coronal mass
ejection, or CME, originating from sunspot region 1093 would trigger auroral
displays around the world, just like those that occurred last week; however,
because this CME was not fully Earth-directed, most of the CME missed the
magnetosphere, resulting in only the slightest increase in geomagnetic
activity between August 10 and 11.
This flare -- one of the biggest since the start of Solar Cycle 24 -- also
triggered a metric type II radio burst. This kind of radio burst can be
heard from a radio receiver tuned to, say, a 6 meter frequency as the burst
occurs. The burst sounds like rushing wind. You can hear a recording of a
type II radio burst as recorded on 50 MHz by Thomas Ashcraft on April 2,
2001 at 2151 UTC that occurred during the X22.0-magnitude X-ray flare.
Incidentally, the April 2, 2001 flare is the second largest event on record
after the X28.0-magnitude mega-flare that occurred on November 4, 2003...
More at http://www.arrl.org/news/the-k7ra-solar-update-125
Mike Terry via dxld yg (13/8-2010)
The K7RA Solar Update
Sunspot numbers and solar flux declined this week, with the average daily
sunspot numbers down more than 15 points to 20.3, and the average daily
solar flux down nearly 4 points to 81.4. These are the numbers from last
Thursday through this Wednesday, July 29-August 5. A new sunspot group
emerged Wednesday, and three more appeared on Thursday...
Full report at http://www.arrl.org/news/the-k7ra-solar-update-124
Mike Terry via dxld yg (6/8-2010)
Space Weather News for August 1, 2010
During the early hours of August 1st, NASA's Solar Dynamics Observatory
recorded a complex global disturbance on the Earth-facing side of the sun.
Most of the sun's northern hemisphere was involved in the event, which
included a long-duration C3-class solar flare, a "solar tsunami," and a
massive filament eruption. As a result of these blasts, a coronal mass
ejection (CME) is heading toward Earth. High-latitude geomagnetic storms
and auroras are possible when the cloud arrives a few days hence. Check
http://spaceweather.com for movies and updates.
Mike Terry via dxld yg (1/8-2010)
Erupting sunspot will soon face Earth
NASA's Solar Dynamics Observatory recorded a flare during the early hours of
8 July. It heralds the approach of a sunspot - possibly a big one - that has
been erupting on the far side of the sun for days.
Read more at
SpaceWeather.com (8/7-2010) via Mike Terry via dxld yg (10/7-2010)
Space Weather News
A high-speed solar wind stream hit Earth's magnetic field last night (May
2-3), sparking a geomagnetic storm that lasted more than 15 hours. In
Scandinavia, the Northern Lights were so bright they could be seen through
the glow of the midnight sun. Red auroras spilled across the Canadian border
and were spotted in several US states.
Details and images are features in today's edition of http://spaceweather.com.
(Not known if any unusual propagation effects reported).
Mike Terry via dxld yg (3/5-2010)
Propagation Forecast Bulletin 16 ARLP016
A Sun with no sunspots! The quiet Sun returned -- and through
Thursday, April 22 there have been eight days straight with no
A new spot began to emerge on Wednesday, but it quickly faded. For
the next ten days NOAA/USAF predict solar flux at 78, 78, 80, 80,
80, 78, 76, 80, 80 and 80. Solar flux values above 80 aren't
predicted until May 20-23, with a value of 85, but that is too far
into the future to predict accurately. They also predict the return
of sunspot group 1061 on April 23-25. That sunspot group was
previously visible on April 5-10.
More at http://www.arrl.org/news/the-k7ra-solar-update-109
From Tad Cook, K7RA
Seattle, WA April 23, 2010 via Mike Terry via dxld yg (24/4-2010)
A strong geomagnetic storm on Monday and Tuesday, April 5-6, was the biggest
since 2006, at least in terms of high planetary A index.
Details here http://www.arrl.org/
Mike Terry via dxld yg (10/4-2010)
Over the weekend, big sunspot 1057 emitted a series of radio bursts that
caused roaring sounds to issue from the loudspeakers of shortwave receivers.
Visit today's edition of http://spaceweather.com to hear a sample "roar" and
to find out how you can build your own solar radio burst monitor.
Space Weather News for March 29, 2010
Mike Terry via dxld yg (30/3-2010)
Sun begins new solar cycle, flinging radiation at the Earth.
As a new solar cycle of activity begins this year, the Earth will once again
be bombarded with increased radiation from the sun. This effect may damage
satellites and interfere with GPS, television and communications...
Full story at http://www.dw-world.de/dw/article/0,,5323618,00.html
Mike Terry via dxld yg (15/3-2010)
We experienced a bit of a scare this week when four days went by with no sunspots. That's right -- for the first time in three months we saw more than a single day with a sunspot number of zero, and that last period was back during November 23 through December 8...
Full story at http://www.southgatearc.org/propagation/2010/k7ra/march_13.htm
Mike Terry via dxld yg (15/3-2010)
Big sunspot sparks solar activity
Spaceweather reports that the sudden emergence of big sunspot 1045 over the
weekend has caused a sharp uptick in solar activity.
The active region has produced three M-class and almost a dozen C-class
solar flares since it appeared on Saturday.
The strongest blast, an M6-class eruption on February 7th, may have hurled a
coronal mass ejection toward Earth.
High-latitude sky watchers should be alert for auroras in the nights ahead
as a result of this activity. Also, ham radio operators are picking up
strong solar radio bursts using shortwave receivers.
Sample sounds and images may be found at http://spaceweather.com
Mike Terry, dxld yg (8/2-2010)