Propagation Summary
Conditions have remained fairly steady during October. The solar Flux actually reached 90 on the 20th, but it should fall to 75 by November 1st then rise again to 85 by mid November. The Boulder A index should stay at 5 and the K index at 2 during the first half of November. So far during 2010, there have been 45 spotless days (15%) , compared 260 in 2009 (71%). http://www.wm7d.net/hamradio/solar/27d_forecast.shtml )
Meteor Showers
Earth is passing through a stream of debris from Halley's Comet, and this is causing the annual Orionid meteor shower. Bright moonlight is reducing the number of visible meteors; nevertheless, sky watchers are reporting some bright Orionids.
Meteor showers provide a very significant increase in the number of meteor trails that can be used for radio communications. These showers arrive at fixed times of the year, appearing on an annual basis. Some are small, whereas others are much larger and can last for several days. There are hundreds or possibly even thousands of these showers. The smaller showers are not easy to distinguish, but some of the larger showers produce a spectacular display if their occurrence coincides with a clear night.
When a meteor shower is observed it will be seen that the meteors appear to come from a single point in the sky which is known as the "radiant". This is a perspective effect caused by the fact that all the particles enter the Earth's atmosphere parallel to one another. The radiant gives rise to the name of the shower - the Perseids shower has its radiant in the constellation of Perseus.
Showers are caused by groups of particles orbiting the Sun in an elliptical orbit. Usually they are associated with comets which leave their debris behind them. Although not all meteor showers have been linked to particular comets, it is thought that all showers come from this source.
Showers vary in intensity from one year to the next. This happens because the particles are not evenly spread around their orbit. One of the most reliable and constant showers is the Perseids shower, but even this one shows some significant variations from one year to the next.
Meteor showers forecast for November are:
Taurids from 25 October to 25 November peaking on November 4th. Leonids: 15 - 19 November peaking on the 17th. Cephids 7 - 9 November peaking on the 11th More details at: http://surf.to/meteorscatter See also: http://stardate.org/nightsky/meteors and: www.spaceweather.com (Via Mike Terry)
DX Info Centre
Here is a website all about FM and UHF DX’ing. Subjects covered included are Tropospheric Ducting and E Skip. There are also many world maps showing colour coded event forecasts, plus links to other relevant websites: www.dxinfocentre.com/
Links to these articles and more can be found at: www.jameswelsh.org.uk
Saturday, 23 October 2010
Thursday, 23 September 2010
October 2010
Propagation Summary
Conditions have remained fairly steady during September. October should begin quiet apart from a slight disturbance on the 5th and the 12th . The Boulder A index is peaking at around 10 every 7 days, and the K index is varying between 2 and 3 during these peaks. Sunspot numbers have remained around the 80 mark during August and September. October should remain the same. According to the trend charts at Solar Cycle 24.com, the Solar flux is forecast to reach 100 by the end of 2010, but after a drop in mid 2010, numbers have continued to remain at around 80 and if this trend continues, it will not reach the predicted peak of 140 by 2014.
Solar Storms can Change Directions, Surprising Forecasters
Solar storms don't always travel in a straight line. But once they start heading in our direction, they can accelerate rapidly, gathering steam for a harder hit on Earth's magnetic field.
So say researchers who have been using data from NASA's twin STEREO spacecraft to unravel the 3D structure of solar storms.
Their findings are presented in Nature Communications. Magazine "This really surprised us," says co-author Peter Gallagher of Trinity College in Dublin. "Solar coronal mass ejections (CMEs) can start out going one way—and then turn in a different direction." The result was so strange, at first they thought they'd done something wrong. After double- and triple-checking their work on dozens of eruptions, however, the team knew they were onto something. The sun's global magnetic field, which is shaped like a bar magnet, guides the wayward CMEs back toward the sun's equator. When the clouds reach low latitudes, they get caught up in the solar wind and head out toward the planets—"like a cork bobbing along a
river," says Gallagher. (NASA Science News 21 September 2010)
Solar Probe to Plunge Directly into Sun's Atmosphere
NASA's plan to visit the sun took a leap forward today with the selection of five key science investigations for the Solar Probe spacecraft. Slated to launch no later than 2018, the smart car-sized spacecraft will plunge directly into the atmosphere of the sun, aiming to solve some of the biggest mysteries of solar physics. This means that researchers can begin building sensors for ‘in situ’ measurements of the solar system's innermost frontier. Lika Guhathakurta, NASA Solar Probe Programme scientist said: "For the first time, we'll be able to 'touch, taste and smell' the sun." Last year, NASA invited top researchers around the world to submit proposals detailing possible science investigations for the pioneering spacecraft. More details at: NASA Science News
About Sunspot Cycles
Dark spots appear at places on the Sun where its magnetic field is concentrated. The number of sunspots is controlled by the amount of distortion of the Sun's magnetic field. The magnetic field becomes distorted because the Sun's equator and core rotate more quickly than its other parts. As a result, sunspot activity varies over an average 11-year cycle. During this period, the Sun goes from a solar minimum (fewer spots) to a solar maximum (more spots) and back to a minimum again. The solar magnetic activity cycle is the main source of the ~10.7 year periodic solar variation, which drives variations in space weather and to some degree weather on the ground and possibly climate change. (BBC article via Ken Fletcher)
Thanks to Ken Fletcher and Mike Terry for regular updates.
Conditions have remained fairly steady during September. October should begin quiet apart from a slight disturbance on the 5th and the 12th . The Boulder A index is peaking at around 10 every 7 days, and the K index is varying between 2 and 3 during these peaks. Sunspot numbers have remained around the 80 mark during August and September. October should remain the same. According to the trend charts at Solar Cycle 24.com, the Solar flux is forecast to reach 100 by the end of 2010, but after a drop in mid 2010, numbers have continued to remain at around 80 and if this trend continues, it will not reach the predicted peak of 140 by 2014.
Solar Storms can Change Directions, Surprising Forecasters
Solar storms don't always travel in a straight line. But once they start heading in our direction, they can accelerate rapidly, gathering steam for a harder hit on Earth's magnetic field.
So say researchers who have been using data from NASA's twin STEREO spacecraft to unravel the 3D structure of solar storms.
Their findings are presented in Nature Communications. Magazine "This really surprised us," says co-author Peter Gallagher of Trinity College in Dublin. "Solar coronal mass ejections (CMEs) can start out going one way—and then turn in a different direction." The result was so strange, at first they thought they'd done something wrong. After double- and triple-checking their work on dozens of eruptions, however, the team knew they were onto something. The sun's global magnetic field, which is shaped like a bar magnet, guides the wayward CMEs back toward the sun's equator. When the clouds reach low latitudes, they get caught up in the solar wind and head out toward the planets—"like a cork bobbing along a
river," says Gallagher. (NASA Science News 21 September 2010)
Solar Probe to Plunge Directly into Sun's Atmosphere
NASA's plan to visit the sun took a leap forward today with the selection of five key science investigations for the Solar Probe spacecraft. Slated to launch no later than 2018, the smart car-sized spacecraft will plunge directly into the atmosphere of the sun, aiming to solve some of the biggest mysteries of solar physics. This means that researchers can begin building sensors for ‘in situ’ measurements of the solar system's innermost frontier. Lika Guhathakurta, NASA Solar Probe Programme scientist said: "For the first time, we'll be able to 'touch, taste and smell' the sun." Last year, NASA invited top researchers around the world to submit proposals detailing possible science investigations for the pioneering spacecraft. More details at: NASA Science News
About Sunspot Cycles
Dark spots appear at places on the Sun where its magnetic field is concentrated. The number of sunspots is controlled by the amount of distortion of the Sun's magnetic field. The magnetic field becomes distorted because the Sun's equator and core rotate more quickly than its other parts. As a result, sunspot activity varies over an average 11-year cycle. During this period, the Sun goes from a solar minimum (fewer spots) to a solar maximum (more spots) and back to a minimum again. The solar magnetic activity cycle is the main source of the ~10.7 year periodic solar variation, which drives variations in space weather and to some degree weather on the ground and possibly climate change. (BBC article via Ken Fletcher)
Thanks to Ken Fletcher and Mike Terry for regular updates.
Wednesday, 18 August 2010
September 2010
Propagation Summary
August has been an interesting month with a massive M1 Solar Flare on August 7th which narrowly missed earth and resulted in the Northern Lights being visible as far south as Iowa, USA. A Persuid meteor shower also passed the Earth over a few days around 12th August which was actually visible to the naked eye in some parts of the world, which should have produced some interesting results for Radio Amateurs. (The next Persuid Meteor shower is forecast for 5-17 September, peaking on the 9th. http://www.imo.net/calendar/2010#julsep )
The NOAA report that On Saturday, August 14, 2010 a small solar flare erupted on the Sun at about 6am EDT. Associated with this flare was a coronal mass ejection (CME) that was partially directed towards the Earth. Also associated with this event was a S1 or minor solar radiation storm on the NOAA Space Weather Scales. The only impacts expected for a solar radiation storm of this magnitude are minor impacts to HF radio communications in the polar regions. However, this is the first solar radiation storm of Solar Cycle 24 and the first solar radiation storm since December of 2006. http://www.swpc.noaa.gov/ .
However, the sunspot number progression chart at Solarcycle24.com still shows sunspot activity to be actually lower than predicted. ( http://solarcycle24.com/sunspots.htm ) Apart from a noticeable disturbance around the 23rd, August should end with relatively steady conditions with the Boulder A index at 5 and the K index at 2, and is forecast to remain the same until mid September. The Solar Flux is forecast to return to a steady 85 during this period. WM7D.net
Solar Cycle 25
Peaking around 2022, Solar Cycle 25 could be one of the weakest in centuries.
The Sun's Great Conveyor Belt has slowed to a record-low crawl, according to research by NASA solar physicist David Hathaway. "It's off the bottom of the charts," he says. "This has important repercussions for future solar activity." http://www.physorg.com/news66581392.html
Radio Fadeouts and Solar Flares
Solar flares produce copious amounts of electromagnetic radiation, the X-ray component of which increases the ionisation of the ionospheric D layer. HF communication generally depends on the reflection of signals from the higher F layer and such signals must travel through the D layer at least twice. Increased ionisation results in greater absorption of the signal in the D layer.
This effect is known as a short-wave fadeout (SWF) and is observed as an increased attenuation of HF signals particularly at the lower frequencies. The fadeout follows closely the pattern of the solar flare, being observed at the same time as the flare. Fadeouts mostly have a rapid onset of a few minutes and a slower decline lasting perhaps an hour (this is highly variable).
A property of SWFs is that they affect the lower HF frequencies more than the higher ones which may not be affected at all. The high frequencies are the last to be affected and the first to recover.
An important feature of SWFs is that the HF circuit is affected only if there is an ionospheric reflection point for the signal in the sunlit hemisphere. No effect is observed if all the reflection points are located in the night hemisphere which is shadowed from the X-rays from the flare.
The intensity of flares at X-ray wavelengths allows us to estimate the extent (both geographical and in frequency) of a fadeout. This intensity is now measured by satellite and so IPS has established a page on the Internet to show the extent of fadeouts in near real-time at:
http://www.ips.gov.au/HF_Systems/6/2/1
Links to these articles and more can be found at www.jameswelsh.org.uk
August has been an interesting month with a massive M1 Solar Flare on August 7th which narrowly missed earth and resulted in the Northern Lights being visible as far south as Iowa, USA. A Persuid meteor shower also passed the Earth over a few days around 12th August which was actually visible to the naked eye in some parts of the world, which should have produced some interesting results for Radio Amateurs. (The next Persuid Meteor shower is forecast for 5-17 September, peaking on the 9th. http://www.imo.net/calendar/2010#julsep )
The NOAA report that On Saturday, August 14, 2010 a small solar flare erupted on the Sun at about 6am EDT. Associated with this flare was a coronal mass ejection (CME) that was partially directed towards the Earth. Also associated with this event was a S1 or minor solar radiation storm on the NOAA Space Weather Scales. The only impacts expected for a solar radiation storm of this magnitude are minor impacts to HF radio communications in the polar regions. However, this is the first solar radiation storm of Solar Cycle 24 and the first solar radiation storm since December of 2006. http://www.swpc.noaa.gov/ .
However, the sunspot number progression chart at Solarcycle24.com still shows sunspot activity to be actually lower than predicted. ( http://solarcycle24.com/sunspots.htm ) Apart from a noticeable disturbance around the 23rd, August should end with relatively steady conditions with the Boulder A index at 5 and the K index at 2, and is forecast to remain the same until mid September. The Solar Flux is forecast to return to a steady 85 during this period. WM7D.net
Solar Cycle 25
Peaking around 2022, Solar Cycle 25 could be one of the weakest in centuries.
The Sun's Great Conveyor Belt has slowed to a record-low crawl, according to research by NASA solar physicist David Hathaway. "It's off the bottom of the charts," he says. "This has important repercussions for future solar activity." http://www.physorg.com/news66581392.html
Radio Fadeouts and Solar Flares
Solar flares produce copious amounts of electromagnetic radiation, the X-ray component of which increases the ionisation of the ionospheric D layer. HF communication generally depends on the reflection of signals from the higher F layer and such signals must travel through the D layer at least twice. Increased ionisation results in greater absorption of the signal in the D layer.
This effect is known as a short-wave fadeout (SWF) and is observed as an increased attenuation of HF signals particularly at the lower frequencies. The fadeout follows closely the pattern of the solar flare, being observed at the same time as the flare. Fadeouts mostly have a rapid onset of a few minutes and a slower decline lasting perhaps an hour (this is highly variable).
A property of SWFs is that they affect the lower HF frequencies more than the higher ones which may not be affected at all. The high frequencies are the last to be affected and the first to recover.
An important feature of SWFs is that the HF circuit is affected only if there is an ionospheric reflection point for the signal in the sunlit hemisphere. No effect is observed if all the reflection points are located in the night hemisphere which is shadowed from the X-rays from the flare.
The intensity of flares at X-ray wavelengths allows us to estimate the extent (both geographical and in frequency) of a fadeout. This intensity is now measured by satellite and so IPS has established a page on the Internet to show the extent of fadeouts in near real-time at:
http://www.ips.gov.au/HF_Systems/6/2/1
Links to these articles and more can be found at www.jameswelsh.org.uk
Saturday, 24 July 2010
August 2010
Propagation Summary
Conditions have remained the same during July, apart from the slight disturbance between the 23rd and the 28th (Sunspot Number 1084) during which the Boulder A index will have gone as high as 15 and the K index wil have hit 5. The Solar Flux will have dropped to 72 by 1st August, returning to it’s the recent ‘norm’ of 80 by the August 6th. ( From: http://www.wm7d.net/hamradio/solar/27d_forecast.shtml )
Sunspot numbers are still around 50% below the targets forecast by Solarcycle24.com (http://solarcycle24.com/sunspots.htm ) See also Steve Nichols’ UK Short Path Propagation Forecast at: http://www.infotechcomms.net/propcharts/
Steve Nichol (GOKYA) ‘s Propagation Forecast
“Some people have suggested that the bands are improving, but I think they are confusing Sporadic E (Es) openings with F layer. This seasonal effect is opening up 20-10m and even 6m and 2m with good, strong openings up to 1,300 miles.
Multi-hop Es is stretching this even further, but we are not seeing an improvement in F layer propagation and Es will be less prevalent as the summer wears on.
Mid-to-late September will be the acid test – and with flux levels in the 70s we are not going to see many trans-Atlantic openings on 10m. Sorry!
20m (14MHz) is likely to be the best DX band between sunrise and sunset, although the band will be noisier than the winter period and not as reliable for long-haul contacts. The higher MUFs at night mean that 20m may remain open during the evening to DX. Short skip may also be possible due to summer sporadic-E.” http://www.g0kya.blogspot.com/
All About Sporadic E
“Sporadic E is irregular scattered patches of relatively dense ionization that develop seasonally within the E region and that reflect and scatter radio frequencies up to 150 MHz. Sporadic E is a regular daytime occurrence over the equatorial regions and is common in the temperate latitudes in late spring ,early summer and, to a lesser degree, in early winter. At high, i.e., polar, latitudes, Sporadic E can accompany Auroras and associated disturbed magnetic conditions. It can sometimes support reflections for distances up to 2,400 km.
Sporadic E is a form of propagation that can arise with little warning, and enable radio frequencies of 150 MHz and more to travel over distances of a thousand kilometres and more. Many people will have experienced it in the days of the old VHF TV transmissions.
When sporadic E propagation arose, it would result in severe interference to the signals. Even now VHF FM broadcasts in the 88 - 108 MHz band can be affected. In many instances the arrival of Sporadic E can cause unwanted interference as signals that are normally too distant to be heard appear. possible.
Sporadic E arises when clouds of intense ionisation form in the region of the E layer. These clouds can have very high levels of ionisation, allowing frequencies up to about 150 MHz to be reflected on some occasions. The clouds are usually comparatively small, measuring only about 50 to 150 kilometres in diameter. Their shape is irregular. Sometimes they may be almost circular, whereas others may be long and thin. They are also surprisingly thin, often only measuring a few hundred metres in depth.
These clouds appear almost at random, although there are times when they are more likely to occur. They form in the day, and dissipate within a few hours. You can read the complete article at:
http://www.g4xgt.co.uk/what-is-sporadic-e.htm
There are also some extra Sporadic E related links and more at: www.jameswelsh.org.uk
Conditions have remained the same during July, apart from the slight disturbance between the 23rd and the 28th (Sunspot Number 1084) during which the Boulder A index will have gone as high as 15 and the K index wil have hit 5. The Solar Flux will have dropped to 72 by 1st August, returning to it’s the recent ‘norm’ of 80 by the August 6th. ( From: http://www.wm7d.net/hamradio/solar/27d_forecast.shtml )
Sunspot numbers are still around 50% below the targets forecast by Solarcycle24.com (http://solarcycle24.com/sunspots.htm ) See also Steve Nichols’ UK Short Path Propagation Forecast at: http://www.infotechcomms.net/propcharts/
Steve Nichol (GOKYA) ‘s Propagation Forecast
“Some people have suggested that the bands are improving, but I think they are confusing Sporadic E (Es) openings with F layer. This seasonal effect is opening up 20-10m and even 6m and 2m with good, strong openings up to 1,300 miles.
Multi-hop Es is stretching this even further, but we are not seeing an improvement in F layer propagation and Es will be less prevalent as the summer wears on.
Mid-to-late September will be the acid test – and with flux levels in the 70s we are not going to see many trans-Atlantic openings on 10m. Sorry!
20m (14MHz) is likely to be the best DX band between sunrise and sunset, although the band will be noisier than the winter period and not as reliable for long-haul contacts. The higher MUFs at night mean that 20m may remain open during the evening to DX. Short skip may also be possible due to summer sporadic-E.” http://www.g0kya.blogspot.com/
All About Sporadic E
“Sporadic E is irregular scattered patches of relatively dense ionization that develop seasonally within the E region and that reflect and scatter radio frequencies up to 150 MHz. Sporadic E is a regular daytime occurrence over the equatorial regions and is common in the temperate latitudes in late spring ,early summer and, to a lesser degree, in early winter. At high, i.e., polar, latitudes, Sporadic E can accompany Auroras and associated disturbed magnetic conditions. It can sometimes support reflections for distances up to 2,400 km.
Sporadic E is a form of propagation that can arise with little warning, and enable radio frequencies of 150 MHz and more to travel over distances of a thousand kilometres and more. Many people will have experienced it in the days of the old VHF TV transmissions.
When sporadic E propagation arose, it would result in severe interference to the signals. Even now VHF FM broadcasts in the 88 - 108 MHz band can be affected. In many instances the arrival of Sporadic E can cause unwanted interference as signals that are normally too distant to be heard appear. possible.
Sporadic E arises when clouds of intense ionisation form in the region of the E layer. These clouds can have very high levels of ionisation, allowing frequencies up to about 150 MHz to be reflected on some occasions. The clouds are usually comparatively small, measuring only about 50 to 150 kilometres in diameter. Their shape is irregular. Sometimes they may be almost circular, whereas others may be long and thin. They are also surprisingly thin, often only measuring a few hundred metres in depth.
These clouds appear almost at random, although there are times when they are more likely to occur. They form in the day, and dissipate within a few hours. You can read the complete article at:
http://www.g4xgt.co.uk/what-is-sporadic-e.htm
There are also some extra Sporadic E related links and more at: www.jameswelsh.org.uk
Saturday, 26 June 2010
July 2010
Propagation Summary
Conditions have remained the same during June except for a fluctuation around the 26th which seems to be happening roughly every 16 days. As far as the Boulder A and K indices are concerned, the ‘floor’ levels are 5 and 2 respectively. The A index rises to between 10 and 15, and the K index rises from 2 to 3 during these fluctuations, the next one being around 13th July . The Solar flux however, is once again on a downward trend. The solar flux is expected to be 75 at the end of June, dropping to 70 by June 19th.
Solar Storm Watch
This is a project by the Royal Observatory an Greenwich where the public are invited to take part in predicting the direction of Coronal Mass Ejections on the sun from online diagrams and videos. The method is known as crowd sourcing. Scientist Chris Davies said: “The reason that we want lots of people doing this is because that takes away the subjectivity. If we have a consensus view of what a CME looks like and which way it's going then you can be much more confident about that answer being correct.” Anybody can take part by registering at: www.solarstormwatch.com (Via Ken Fletcher).
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. Sunspots are cool dark regions on the solar surface with strong magnetic fields. There have been few direct measurements of changes in the physical parameters of sunspots, but here we present a study which shows that sunspots are becoming warmer and have weaker magnetic fields. The number of sunspots visible on the Sun normally shows an 11-year periodicity, and the current sunspot cycle (cycle 23) had a maximum in 2001, and is entering a minimum phase with few sunspots currently visible. Our data show that there are additional changes occurring in sunspots, independent of the sunspot cycle, and these trends suggest that sunspots will disappear completely.” (National Solar Observatory Tucson, Arizona) This report can be viewed in full at:
http://wattsupwiththat.files.wordpress.com/2008/06/livingston-penn_sunspots2.pdf (Alerted by Glenn Hauser, in his latest World of Radio: www.worldofradio.com)
Solar Dynamics Observatory delivers stunning images
The Solar Dynamics Observatory (SDO) is returning stunning pictures of the sun.
Launched February 11, it carries six image sensors from UK company e2v based in Chelmsford, Essex.
NASA's Solar Dynamics Observatory is returning early images that confirm an unprecedented new capability for scientists to better understand our sun’s dynamic processes.
Some of the images from the spacecraft show never-before-seen detail of material streaming outward and away from sunspots. Others show extreme close-ups of activity on the sun’s surface.
The spacecraft also has made the first high-resolution measurements of solar flares in a broad range of extreme ultraviolet wavelengths. "These initial images show a dynamic sun that I had never seen in more than 40 years of solar research,” said Richard Fisher, director of the Heliophysics Division at NASA Headquarters in Washington. "SDO will change our understanding of the sun and its processes, which affect our lives and society. This mission will have a huge impact on science, similar to the impact of the Hubble Space Telescope on modern astrophysics.”
‘A Solar Prominence’ is a video of the March 30, 2010 prominence eruption, starting with a zoomed in view. The twisting motion of the material is the most noticeable feature. The viewpoint then pulls out to show the entire Sun.
Watch it at: http://www.nasa.gov/mov/445814main_Pesnell_7-Prominence-H264.mov
Other SDO images at
http://www.nasa.gov/mission_pages/sdo/news/briefing-materials-20100421.html
NASA's New Eye on the Sun Delivers Stunning First Images
http://www.nasa.gov/mission_pages/sdo/news/first-light.html
Successful launch for SDO
http://www.southgatearc.org/news/february2010/
sdo_launched.htm
This was also featured on News Briefing BBC Radio 4 22nd April 2010.
(Via Ken Fletcher with thanks to Mike Terry and Southgate ARC)
Conditions have remained the same during June except for a fluctuation around the 26th which seems to be happening roughly every 16 days. As far as the Boulder A and K indices are concerned, the ‘floor’ levels are 5 and 2 respectively. The A index rises to between 10 and 15, and the K index rises from 2 to 3 during these fluctuations, the next one being around 13th July . The Solar flux however, is once again on a downward trend. The solar flux is expected to be 75 at the end of June, dropping to 70 by June 19th.
Solar Storm Watch
This is a project by the Royal Observatory an Greenwich where the public are invited to take part in predicting the direction of Coronal Mass Ejections on the sun from online diagrams and videos. The method is known as crowd sourcing. Scientist Chris Davies said: “The reason that we want lots of people doing this is because that takes away the subjectivity. If we have a consensus view of what a CME looks like and which way it's going then you can be much more confident about that answer being correct.” Anybody can take part by registering at: www.solarstormwatch.com (Via Ken Fletcher).
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. Sunspots are cool dark regions on the solar surface with strong magnetic fields. There have been few direct measurements of changes in the physical parameters of sunspots, but here we present a study which shows that sunspots are becoming warmer and have weaker magnetic fields. The number of sunspots visible on the Sun normally shows an 11-year periodicity, and the current sunspot cycle (cycle 23) had a maximum in 2001, and is entering a minimum phase with few sunspots currently visible. Our data show that there are additional changes occurring in sunspots, independent of the sunspot cycle, and these trends suggest that sunspots will disappear completely.” (National Solar Observatory Tucson, Arizona) This report can be viewed in full at:
http://wattsupwiththat.files.wordpress.com/2008/06/livingston-penn_sunspots2.pdf (Alerted by Glenn Hauser, in his latest World of Radio: www.worldofradio.com)
Solar Dynamics Observatory delivers stunning images
The Solar Dynamics Observatory (SDO) is returning stunning pictures of the sun.
Launched February 11, it carries six image sensors from UK company e2v based in Chelmsford, Essex.
NASA's Solar Dynamics Observatory is returning early images that confirm an unprecedented new capability for scientists to better understand our sun’s dynamic processes.
Some of the images from the spacecraft show never-before-seen detail of material streaming outward and away from sunspots. Others show extreme close-ups of activity on the sun’s surface.
The spacecraft also has made the first high-resolution measurements of solar flares in a broad range of extreme ultraviolet wavelengths. "These initial images show a dynamic sun that I had never seen in more than 40 years of solar research,” said Richard Fisher, director of the Heliophysics Division at NASA Headquarters in Washington. "SDO will change our understanding of the sun and its processes, which affect our lives and society. This mission will have a huge impact on science, similar to the impact of the Hubble Space Telescope on modern astrophysics.”
‘A Solar Prominence’ is a video of the March 30, 2010 prominence eruption, starting with a zoomed in view. The twisting motion of the material is the most noticeable feature. The viewpoint then pulls out to show the entire Sun.
Watch it at: http://www.nasa.gov/mov/445814main_Pesnell_7-Prominence-H264.mov
Other SDO images at
http://www.nasa.gov/mission_pages/sdo/news/briefing-materials-20100421.html
NASA's New Eye on the Sun Delivers Stunning First Images
http://www.nasa.gov/mission_pages/sdo/news/first-light.html
Successful launch for SDO
http://www.southgatearc.org/news/february2010/
sdo_launched.htm
This was also featured on News Briefing BBC Radio 4 22nd April 2010.
(Via Ken Fletcher with thanks to Mike Terry and Southgate ARC)
Wednesday, 19 May 2010
June 2010
Propagation Summary
The bank Holiday weekend of 29-30 May will have seen a noticeable disturbance of HF reception with the Boulder A index as high as 25 and the K index at 5. The first half of June should be fairly calm with the A index at 5 and the K index at 2. The Solar flux will go from 80 down to 70 during this period. .Maximum Useable frequencies for June are likely to remain between 6 and 7 Mhz. (http://www.wm7d.net/hamradio/solar/27d_forecast.shtml) Comprehensive forecasts and summaries, including charts and satellite images can also be found at: (http://prop.hfradio.org/)
HF Propagation Report May 2010“Solar conditions have not been very good in the last month. In fact we had a run of about 12 days without a single sunspot. With the solar flux hovering around 74 it was like a return to the minimum once again. Solar flare activity has been low, but even a small change in the Interplanetary Magnetic Field (Bz) swinging south was enough to cause the HF bands to misbehave.” More details in G0KYA's Amateur Radio Blog: http://www.g0kya.blogspot.com/
(Via Mike Terry)
Sunspot Numbers Are Lower Than Forecast
The Sunspot trend charts on Solarcycle 24.com, are showing a significant drop in sunspot activity in the first quarter of 2010. The smoothed average sunspot forecast for the end of April, for example is 25 but the actual figure for April is as low as 10. The Sunspot trend charts and more can be viewed at: http://solarcycle24.com/sunspots.htm
First Light for the Solar Dynamics Observatory.
NASA's Solar Dynamics Observatory is beaming back stunning new images of the sun, revealing our own star as never seen before. Even veteran solar physicists say they are amazed by the data. At a press conference in Washington DC 21at April,, researchers unveiled "First Light" images from NASA's Solar Dynamics Observatory, a space telescope designed to study the sun.
"SDO is working beautifully," reports project scientist Dean Pesnell of the Goddard Space Flight Centre. "This is even better than we could have dreamed." Launched on February 11th from Cape Canaveral, the observatory has spent the past two months moving into a geosynchronious orbit and activating its instruments. As soon as SDO's telescope doors opened, the spacecraft began beaming back scenes so beautiful and puzzlingly complex that even seasoned observers were stunned.
"We've seen solar prominences before—but never quite like this," says Alan Title of Lockheed Martin, principal investigator of the Atmospheric Imaging Assembly (AIA), the observatory's main telescope array. "Some of my colleagues say they've learned new things about prominences just by watching this one movie." SDO is the first mission of NASA's Living with a Star (LWS) program. The goal of LWS is to understand the sun as a magnetic variable star and to measure its impact on life and society on Earth. Program scientist Like Guhathakurta of NASA headquarters envisions big things for the new observatory:
"SDO is our 'Hubble for the sun'," she says. "It promises to transform solar physics in the same way the Hubble Space Telescope has transformed astronomy and cosmology." "No solar telescope has ever come close to the combined spatial, temporal and spectral resolution of SDO," adds Title. "This is possible because of the combination of 4096 x 4096-pixel CCDs with huge dynamic range and a geosynchronious orbit which allows SDO to observe the sun and communicate with the ground around the clock." More details including up to date pictures and video can be found at: http://sohowww.nascom.nasa.gov/pickoftheweek/
Thanks to Ken Fletcher and Mike Terry for regular updates.
Links: www.jameswelsh.org.uk
The bank Holiday weekend of 29-30 May will have seen a noticeable disturbance of HF reception with the Boulder A index as high as 25 and the K index at 5. The first half of June should be fairly calm with the A index at 5 and the K index at 2. The Solar flux will go from 80 down to 70 during this period. .Maximum Useable frequencies for June are likely to remain between 6 and 7 Mhz. (http://www.wm7d.net/hamradio/solar/27d_forecast.shtml) Comprehensive forecasts and summaries, including charts and satellite images can also be found at: (http://prop.hfradio.org/)
HF Propagation Report May 2010“Solar conditions have not been very good in the last month. In fact we had a run of about 12 days without a single sunspot. With the solar flux hovering around 74 it was like a return to the minimum once again. Solar flare activity has been low, but even a small change in the Interplanetary Magnetic Field (Bz) swinging south was enough to cause the HF bands to misbehave.” More details in G0KYA's Amateur Radio Blog: http://www.g0kya.blogspot.com/
(Via Mike Terry)
Sunspot Numbers Are Lower Than Forecast
The Sunspot trend charts on Solarcycle 24.com, are showing a significant drop in sunspot activity in the first quarter of 2010. The smoothed average sunspot forecast for the end of April, for example is 25 but the actual figure for April is as low as 10. The Sunspot trend charts and more can be viewed at: http://solarcycle24.com/sunspots.htm
First Light for the Solar Dynamics Observatory.
NASA's Solar Dynamics Observatory is beaming back stunning new images of the sun, revealing our own star as never seen before. Even veteran solar physicists say they are amazed by the data. At a press conference in Washington DC 21at April,, researchers unveiled "First Light" images from NASA's Solar Dynamics Observatory, a space telescope designed to study the sun.
"SDO is working beautifully," reports project scientist Dean Pesnell of the Goddard Space Flight Centre. "This is even better than we could have dreamed." Launched on February 11th from Cape Canaveral, the observatory has spent the past two months moving into a geosynchronious orbit and activating its instruments. As soon as SDO's telescope doors opened, the spacecraft began beaming back scenes so beautiful and puzzlingly complex that even seasoned observers were stunned.
"We've seen solar prominences before—but never quite like this," says Alan Title of Lockheed Martin, principal investigator of the Atmospheric Imaging Assembly (AIA), the observatory's main telescope array. "Some of my colleagues say they've learned new things about prominences just by watching this one movie." SDO is the first mission of NASA's Living with a Star (LWS) program. The goal of LWS is to understand the sun as a magnetic variable star and to measure its impact on life and society on Earth. Program scientist Like Guhathakurta of NASA headquarters envisions big things for the new observatory:
"SDO is our 'Hubble for the sun'," she says. "It promises to transform solar physics in the same way the Hubble Space Telescope has transformed astronomy and cosmology." "No solar telescope has ever come close to the combined spatial, temporal and spectral resolution of SDO," adds Title. "This is possible because of the combination of 4096 x 4096-pixel CCDs with huge dynamic range and a geosynchronious orbit which allows SDO to observe the sun and communicate with the ground around the clock." More details including up to date pictures and video can be found at: http://sohowww.nascom.nasa.gov/pickoftheweek/
Thanks to Ken Fletcher and Mike Terry for regular updates.
Links: www.jameswelsh.org.uk
Saturday, 24 April 2010
May 2010
Propagation Summary
April has remained fairly quiet with occasional disturbances. May should remain the same with a possible disturbance on the 4th and 5th. The Solar Flux is fluctuating between 75 and 84, roughly every 7 days. The Boulder A index is fluctuating in a similar way between 5 and 8, and the K index is likely to remain between 2 and 3 in a similar pattern during May. Conditions are forecast to remain mainly quiet with a 50% probability of C class flares.( http://prop.hfradio.org/ ) Maximum useable frequencies are likely to remain between 6 and 7 Megs during daylight hours.(http://hfradio.org/fot_7.html)
The May report in the Communication Journal has been reduced due to publication of Broadcasts In English
Thanks to Ken Fletcher and Mike Terry for regular updates.
April has remained fairly quiet with occasional disturbances. May should remain the same with a possible disturbance on the 4th and 5th. The Solar Flux is fluctuating between 75 and 84, roughly every 7 days. The Boulder A index is fluctuating in a similar way between 5 and 8, and the K index is likely to remain between 2 and 3 in a similar pattern during May. Conditions are forecast to remain mainly quiet with a 50% probability of C class flares.( http://prop.hfradio.org/ ) Maximum useable frequencies are likely to remain between 6 and 7 Megs during daylight hours.(http://hfradio.org/fot_7.html)
The May report in the Communication Journal has been reduced due to publication of Broadcasts In English
Thanks to Ken Fletcher and Mike Terry for regular updates.
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