Friday, 29 January 2010

February '10

Propagation Forecast
Conditions have remained calm during January, except for a minor disturbance on 20 January caused by Sunspot 1039 which emerged on the far side of the sun on the 19th. Conditions are likely to remain calm until February 16th when a similar disturbance may affect radio propagation. Maximum A index will be 10, returning to the norm of 5 within 2 days. The Boulder K index has remained at 2 during the last 4 weeks rising by 1 point during sunspot activity. The solar Flux is now on a steady upward trend, rising to 84 by 16th February. This is a definite sign of Solar cycle 24 emerging at last. Maximum usablefrequencies during February should remain at between 6 and 7 MHz.

Solar Conditions and Global Temperatures
In This NASA article, John Hansen, director of GISS (Goddard Institute for Space Studies) explains a link between Global temperatures and Solar activity.
“Although 2008 was the coolest year of the decade , due to strong cooling of the tropical Pacific Ocean 2009 saw a return to near-record global temperatures. The past year was only a fraction of a degree cooler than 2005, the warmest year on record, and tied with a cluster of other years -- 1998, 2002, 2003, 2006 and 2007 -- as the second warmest year since record keeping began.
A deep solar minimum has made sunspots a rarity in the last few years. Such lulls in solar activity, which can cause the total amount of energy given off by the sun to decrease by about a tenth of a percent, typically spur surface temperature to dip slightly. Overall, solar minimums and maximums are thought to produce no more than 0.1°C (0.18°F) of cooling or warming.
“In 2009, it was clear that even the deepest solar minimum in the period of satellite data hasn’t stopped global warming from continuing,” said Hansen. (From:

Geomagnetic Storm Levels
The Boulder K Index is the best indicator of solar activity.
Geomagnetic storm levels are determined by the estimated 3-hourly Planetary K-indices which are that are derived in real time from a network of western hemisphere ground-based magnetometers. Geomagnetic storm level. During 2009, the K Index has occasionally reached 5 and will probably exceed this during 2010, as we enter Solar Cycle 24.
Planetary K
Indices Geomagnetic/Storm Level
K=5 G1
K=6 G2
K=7 G3
K=8 G4
K=9 G5

Solar Flare Images
The Scientific front Line website shows video images of a Solar Flare in 2003 recorded by the SOHO (Solar and Heliospheric Observatory) Satellite. These are similar to the solar activity we can expect from Solar Cycle 24. ( )

Meteor Showers in 2010
Meteor showers are produced by small fragments of cosmic debris entering the earth's atmosphere at extremely high speed. Apart from being used in ham radio circles, meteor scatter communications is also used in professional and commercial radio communications applications. It provides a relatively low cost and reliable form of radio communication for medium distances provided that real time data transfer is not required. It is used for radio communications applications such as sending data from remote weather stations and for oil rigs where it provides a useful element of their data communications structure.
2010 began with the intense but brief Quadrantid maximum (January 3/4). The Lyrids past mid-April (max: April 22/23) will raise meteor rates for several nights. The Eta Aquarids (max: May 7/8) enrich late nights of May's first half, sometimes substantially. February, March, and April evenings have another notable feature. An unusual number of sporadic fireballs come in this interval, possibly one every few nights. June to mid-July has fair rates. The last half of July has rates increasing steadily as the Delta Aquarids (July 29/30) and Alpha Capricornids (July 27-28) have maxima at month's end. Even the Perseids are beginning to show a little. Overall, late July to mid-August is very rich in meteors. The Perseid maximum, just before mid-August (August 12/13), is fairly prolonged and quite rich. ( )

Friday, 1 January 2010

Propagation January 2010

Propagation Forecast
January is likely to remain fairly calm with the Boulder A index remaining at 5 and the K index at 2 throughout the month. The Solar flux will start at 80 and should drop to 76 by the end of the month. The Maximum Useable frequencies Western Europe for daylight hours in January are 6-7 MHz.

2009 has seen a total of 209 days of zero sunspot activity (71%), according to and is estimated to be the 5th most spotless year since 1849.

Solar Cycle Prediction
A number of techniques are used to predict the amplitude of a cycle during the time near and before sunspot minimum. Relationships have been found between the size of the next cycle maximum and the length of the previous cycle, the level of activity at sunspot minimum, and the size of the previous cycle.

Predicting the behaviour of a sunspot cycle is fairly reliable once the cycle is well underway (about 3 years after the minimum in sunspot number occurs. Prior to that time the predictions are less reliable but nonetheless equally as important. Planning for satellite orbits and space missions often require knowledge of solar activity levels years in advance. A number of techniques are used to predict the amplitude of a cycle during the time near and before sunspot minimum. Relationships have been found between the size of the next cycle maximum and the length of the previous cycle, the level of activity at sunspot minimum, and the size of the previous cycle.

Among the most reliable techniques are those that use the measurements of changes in the Earth's magnetic field at, and before, sunspot minimum. These changes in the Earth's magnetic field are known to be caused by solar storms but the precise connections between them and future solar activity levels is still uncertain.

Of these "geomagnetic precursor" techniques three stand out. The earliest is from Ohl and Ohl [Solar-Terrestrial Predictions Proceedings, Vol. II. 258 (1979)] They found that the value of the geomagnetic A index at its minimum was related to the sunspot number during the ensuing maximum. The primary disadvantage of this technique is that the minimum in the geomagnetic A index often occurs slightly after sunspot minimum so the prediction isn't available until the sunspot cycle has started.

An alternative method is due to a process suggested by Joan Feynman. She separates the geomagnetic A index into two components: one in phase with and proportional to the sunspot number, the other component is then the remaining signal. This remaining signal faithfully represents the sunspot numbers several years in advance. The maximum in this signal occurs near sunspot minimum and is proportional to the sunspot number during the following maximum. This method does allow for a prediction of the next sunspot maximum at the time of sunspot minimum.

A third method is due to Richard Thompson [Solar Physics 148, 383 (1993)]. He found a relationship between the number of days during a sunspot cycle in which the geomagnetic field was "disturbed" and the amplitude of the next sunspot maximum. His method has the advantage of giving a prediction for the size of the next sunspot maximum well before sunspot minimum.
From: 8 December 2009

Sunspot Plotter
Here is a web page where you can go to a specific date and get sunspot data to compare reception conditions with the Solar conditions at the time.

Thanks to Mike Terry and Ken Fletcher for regular updates

Propagation December '09

No report published due to BDXC Transmissions In English.