Saturday 24 January 2009

February '09

Propagation Forecast
Conditions in January have remained quiet with the A index at 5 and the K index at 2. However, January will end with a disturbance on the 27th, with 'A' index peaking at 5 and the 'K' Index at 3. The 29th should be calm followed by a lesser disturbance on the 30th, then the calm conditions will then remain until at least February 14th. From: http://www.wm7d.net/hamradio/solar/27d_forecast.shtml

Severe Space Weather.
Severe Geomagnetic Storms can affect other things besides radio reception, according to a recent report in NASA Science News. The problem begins with the electric power grid. "Electric power is modern society's cornerstone technology on which virtually all other infrastructures and services depend," the report notes. Yet it is particularly vulnerable to bad space weather. Ground currents induced during geomagnetic storms can actually melt the copper windings of transformers at the heart of many power distribution systems. Sprawling power lines act like antennas, picking up the currents and spreading the problem over a wide area. The most famous geomagnetic power outage happened during a space storm in March 1989 when six million people in Quebec lost power for 9 hours. To estimate the scale of such a failure, report co-author John Kappenmann of the Metatech Corporation looked at the great geomagnetic storm of May 1921, which produced ground currents as much as ten times stronger than the 1989 Quebec storm, and modeled its effect on the modern power grid. He found more than 350 transformers at risk of permanent damage and 130 million people without power. The loss of electricity would ripple across the social infrastructure with "water distribution affected within several hours; perishable foods and medications lost in 12-24 hours; loss of heating/air conditioning, sewage disposal, phone service, fuel re-supply and so on. Read the full article at: http://science.nasa.gov/headlines/y2009/21jan_severespaceweather.htm

NASA'S Mission to Improve Predictions of Violent Space Weather
Sometime between the end of 2008 and the beginning 2009, NASA will launch the Solar Dynamics Observatory (SDO) to trace Solar disturbances back to their origin deep within the sun. SDO will discover how the sun builds up and explosively releases magnetic energy, which powers severe space weather.
"Right now, we can make limited space weather predictions, but they are baby steps compared to our ability to forecast weather on Earth," said Dr. Dean Pesnell of NASA's Goddard Space Flight Centre, Greenbelt, Md., Project Scientist for SDO. "SDO's instruments are designed to work together to tell us more about how solar storms form, which will improve predictions of when they are about to happen."
Heat from nuclear fusion in the sun's core makes its outer layer churn like a pot of boiling water. Solar storms are born deep in this outer layer, with tangled magnetic fields generated by the sun’s churning electrically conducting gas (plasma). Like a rubber band that has been twisted too far, solar magnetic fields can suddenly snap to a new shape, releasing tremendous energy as a solar flare or a coronal mass ejection (CME).
Solar flares are explosions in the sun’s atmosphere, with the largest equal to billions of one-megaton nuclear bombs. Solar magnetic energy can also blast billions of tons of plasma into space at millions of miles (kilometres) per hour as a CME. This violent solar activity often occurs near sunspots, dark regions on the sun caused by concentrated magnetic fields. Sunspots and stormy solar weather follow a cycle that repeats approximately every eleven years, from few sunspots and quiet conditions to many sunspots and active, and back again.
The key to predicting solar storms and the solar activity cycle is an understanding of the flows of plasma inside the sun. Magnetic fields are "frozen" into the solar plasma, so plasma currents within the sun transport, concentrate, and help dissipate solar magnetic fields. Currently, the Sun’s activity is at its minimum, but by the time of the SDO launch, the activity level is expected to rise significantly.
Although the general process of solar activity and its cyclic behaviour are known, many of the details are not, such as exactly what magnetic structures lead to flares and CMEs. These details need to be discovered before solar storm predictions improve, and SDO's suite of three instruments is designed to do just that. ( From: http://www.physorg.com/news123774611.html )
Thanks to Mike Terry and Ken Fletcher for regular updates.

Saturday 3 January 2009

January 2009

Propagation Forecast

Sunspot numbers have progressively dropped so far this century when they started of at around the 120 mark. The end of 2008 has seen al all time low so far this century of 2. Boulder forecast charts estimate a steady yearly increase to around 80 by the second half of 2013. (www.solarcycle24.com)

Solar flux has virtually remained at a steady 70 during December and is forecast to remain the same until the end of January. The Boulder A Index peaked at 12 on 2nd January where it will remain until the end of the month. The Boulder K index, after starting in January at 4, will remain at 2 from the 4th January onwards. This will mean steady conditions throughout the rest of January.

First Meteors Of 2009
The annual Quadrantid meteor shower peaked on Jan. 3rd when Earth entered a stream of debris from shattered comet 2003 EH1. The timing of the encounter favored observers in Western North America and across the Pacific Ocean who could see dozens to hundreds of meteors during the dark hours before sunrise this Saturday morning. Visit http://spaceweather.com for a sky map and more information.

Space Weather Radio
For the new year, Spaceweather.com is pleased to announce a new service: Space Weather Radio, broadcasting live "sounds from space" around the clock. Today you can listen to the Air Force Space Surveillance Radar in Texas. When a meteor passes over the facility--ping!--there is an audible echo. (Activity should be high during the Quadrantid meteor showers) In the near future we'll be adding broadcasts of solar radio bursts and VLF signals from the ionosphere. The streams are punctuated by Daily Space Weather Updates .

2008. Blankest Year Of The Space Age
Astronomers who count sunspots have announced that 2008 is now the "blankest year" of the Space Age. As of Sept. 27, 2008, the sun had been blank, i.e., had no visible sunspots, on 200 days of the year. To find a year with more blank suns, you have to go back to 1954, three years before the launch of Sputnik, when the sun was blank 241 times.
"Sunspot counts are at a 50-year low," says solar physicist David Hathaway of the NASA Marshall Space Flight Center. "We're experiencing a deep minimum of the solar cycle." (www.nasa.gov)

“The sun is behaving normally”. So says NASA solar physicist David Hathaway. "There have been some reports lately that Solar Minimum is lasting longer than it should. That's not true. The ongoing lull in sunspot number is well within historic norms for the solar cycle."
This report, that there's nothing to report, is newsworthy because of a growing buzz in lay and academic circles that something is wrong with the sun. Sun Goes Longer Than Normal Without Producing Sunspots declared one recent press release. A careful look at the data, however, suggests otherwise. But first, a status report: "The sun is now near the low point of its 11-year activity cycle," says Hathaway. "We call this 'Solar Minimum.' It is the period of quiet that separates one Solar Max from another."
During Solar Max, huge sunspots and intense solar flares are a daily occurrence. Auroras appear in Florida. Radiation storms knock out satellites. Radio blackouts frustrate hams. The last such episode took place in the years around 2000-2001.
During Solar Minimum, the opposite occurs. Solar flares are almost nonexistent while whole weeks go by without a single, tiny sunspot to break the monotony of the blank sun. This is what we are experiencing now.
Hathaway has studied international sunspot counts stretching all the way back to 1749 and he offers these statistics: "The average period of a solar cycle is 131 months with a standard deviation of 14 months. Decaying solar cycle 23 (the one we are experiencing now) has so far lasted 142 months--well within the first standard deviation and thus not at all abnormal. The last available 13-month smoothed sunspot number was 5.70. This is bigger than 12 of the last 23 solar minimum values."
In summary, "the current minimum is not abnormally low or long." (Nasa.gov)

Thanks to Mike Terry and Ken Fletcher for regular updates