MAGNETIC OBSERVATORIES LOCATIONS
Graph-3 Zone Review and Forecast
6 Hour - Three Zone Forecast
|12 Hour - Three Zone Forecast
27 DAY MAGNETIC FORECAST
DRX for the zone is the mean of 24, 1 hour values. Because this averaging process has the effect of smoothing (filtering) the more rapid fluctuations in the field, the qualitative descriptors are defined rather differently than for the short-term forecasts. Units are nanoteslas (nT). This could be roughly equivalent to a one-day "A-index"
CURRENT AURORAL OVAL ACTIVITY
Real Time Status Reports
The Reports for the several geographic regions are derived from actual measurements made at magnetic observatories situated in each of the regions. In each case, data are telemetered from the observatory to headquarters in Ottawa, where the data are processed to produce a Kr index to characterize the level of magnetic disturbance measured during the past hour.
For the Eastern North America region, the status report is updated every minute, whereas reports for the other regions are updated every five minutes, because of less frequent data telemetry.
For qualitative comparison, the words describing the activity levels used in other forecast formats in this web site are included. Colours in the display panels change according to the level of the magnetic activity and Kr index, ranging from green, through yellow, amber, orange, to red.
The Forecasts are provided as summaries of the expected activity during the next 3 hours and during the following 3 hours, for each of the regions. Again, for ease of comparison with other sources of information, they are presented in terms of the Kr index. The forecasts are updated every fifteen minutes. The words describing the activity levels and the panel colour scheme used for the Status Reports also apply to the Forecast panels. When appropriate, Major Storm Watches are issued, indicating that conditions are such that Major Storm activity could occur during the time interval. When a watch is in effect, the upper part of the appropriate panel is coloured purple, and a Storm Watch message appears below the Forecast panels.
The Kr index is approximately equivalent to the local K index, but whereas the true K index is not routinely available until the day after data are measured (and then only for three observatories), the Kr index is available almost immediately. The two indices can differ slightly at low levels of activity but are not significantly different at high levels of activity. There are nine levels in the Kr index, as in the K index. Whereas the K index is defined over an interval of 3 hours, the Kr index is defined over an interval of 1 hour. It is derived from the running hourly range computed from the incoming observatory data, and is equivalenced to the K scale.
DRX (24hr Kr mean) "A-index"
The levels of geomagnetic field activity, or disturbance, currently used in the long-term (up to 27 days) forecasts are labelled qualitatively for general usage. For each of the three major zones (subauroral, auroral, polar cap), the range of activity is divided into four classifications: quiet, unsettled, active, storm. The actual parameter used for reporting and forecasting magnetic activity is a daily index. It is known as DRX and is the average of the hourly ranges (maximum minus minimum during each hour) in the X (northward) component of the magnetic field intensity for a day (the UT [or GMT] day), ie DRX for the zone is the mean of 24 values. Because this averaging process has the effect of smoothing (filtering) the more rapid fluctuations in the field, the qualitative descriptors are defined rather differently than for the short-term forecasts. Units are nanoteslas (nT).
Below is a great resource from Solar Terrestrial Dispatch for summarizing topband conditions as a function of AU activity. Go here for detail and more explanation: http://www.spacew.com/www/160pred.html
Estimated Global Topband Conditions: FAIR TO GOOD
Understanding and Using the above
The table above represents a rough approximation of radio propagation conditions on 160 meters (affectionately known as Topband). It is to be used as a guide only and is not a definitive forecast. It is based upon selected high-latitude magnetic observatory data which is used to estimate the influence of the auroral oval on 160 meter path propagation (refer to the March and April 1998 issues of CQ Magazine for details: "160 Meters: An Enigma Shrouded in Mystery", by Cary Oler and Ted Cohen).
Use this map just as you would use a computed distance table. For example, to find the predicted 160 meter propagation conditions between the central United States and Spain, find the central U.S. along the top of the table (it is labelled "c.us", and then find Spain along the left-hand side of the table. Then follow the column and row for the central U.S. and Spain until they converge together in the table. The color you observe in that square dictates whether propagation might be possible between the U.S. and Spain or Spain and the U.S..
A GREY box means that propagation is generally not influenced by the current level of auroral activity. Propagation should therefore be observed more often than not. However, keep in mind that there are almost certainly a myriad of factors that might affect propagation on 160 meters. This table only considers the role geomagnetic and auroral activity might play. Grey boxes should therefore imply that geomagnetic and auroral activity should not affect propagation and that a contact might be possible regardless of the state of the geomagnetic field. Some level of sensibility must be applied, though. For instance, during a severe geomagnetic storm, attempting to contact certain locations identified by a grey box might be an exercise in futility.
A GREEN box means that propagation on the specific path might be possible and that levels of geomagnetic and auroral activity might permit the signal to pass through the high-latitude regions unscathed. It might be worth a try. The four 'mights' in this paragraph are intentional: don't expect this table to provide you with magnificent openings to areas that have green boxes. A green box should be interpreted as a higher potential for DX between the specific paths represented by the green box. Whether your signal actually makes it through to the destination will depend on the location of the auroral oval, the thickness of it, the position of the mid-latitude trough, the effects of the trough and the auroral oval on your signals' behaviour (refraction, absorption, etc), and many other circumstances. But a green box generally implies that the auroral oval is in a good state of inactivity for potentially establishing DX. It indeed may be worth a try.
A YELLOW box implies that your chances of establishing a successful DX contact between the two specific locations is only marginal. It still might be possible, but probably will be difficult and/or short-lived.
A RED box should be interpreted to mean that your odds of making contact between the specific locations is poor to very poor. This does not mean that making contact is impossible. Anyone who works Topband should know how erratic this band can be. But a red box is generally much worse than a yellow or a green box.
The prediction table is designed for the NIGHT-SECTORS ONLY! Absorption in the D-region on daylit circuits is far too high to allow 160-meter contacts. If any part of your signal path crosses into daylight, these tables will be invalid (and so should your signal!).
|Below are soft X-ray solar images. Bright spots indicate active regions or flares. Click the image to see real-time .gif movies of the sun. (from SOHO: http://soho.nascom.nasa.gov/ )|
Below is the latest solar image from SDO (solar dynamics observatory) at an AIA wavelength of 171 (Go here for more images and detail: http://sdo.gsfc.nasa.gov/data/)
Click the image for a larger view...amazing detail!
LONG RANGE LOW-BAND FORECAST ???
|Below is an EXCEL chart showing how the A index changes
relative to sunspot numbers from 1932 till present. Created from raw
data downloaded from:
RED line- Smoothed Monthly Sunspot count, GREEN (fill)-Monthly Mean Ap number, Blue line- Ap moving average.
Notice how the geomagnetic activity seems to be lowest (low Ap) just at the beginning of the up-cycle of each sunspot cycle. This would suggest that geomagnetic conditions are likely to be most quiet during years 2007-2010.
The EXCEL chart below was created by Jerry VE6TL and really shows how the current cycle 24 is 'way behind schedule" !! The black arrows are all 5 years long and it is clear that by now we should be 1/2 to 1/3 up the next cycle but we are only now just starting to come up.
Jerry built this chart from the NRC dataset
Static (QRN) got you down....why can't he copy me????? Maybe he has high QRN !!!
Here are some links to show lightning activity in different parts of the world:
North America: http://www.lightningstorm.com
CURRENT LIGHTNING AROUND THE WORLD
Lightning stroke positions are shown as coloured dots which "cool down" from blue for the most recent (occurring within the last 10 min) through green and yellow to red for the oldest (30-40 minutes earlier).
BACK TO VE6WZ