Australia Propagation Report
Report from IPS Radio and Space Services published for 27 Dec 2007
SUBJ: IPS DAILY HF PROPAGATION REPORT
ISSUED AT 24/2330Z DECEMBER 2007 BY IPS RADIO AND SPACE SERVICES
FORECAST (25 DECEMBER - 27 DECEMBER)
Date T index Conditions MUFs
25 Dec -32 Normal 10 to 30% below predicted monthly
values
26 Dec -35 Normal 10 to 30% below predicted monthly
values
27 Dec -40 Normal 10 to 30% below predicted monthly
values
Webmaster's Note :
For Comparison purposes, IPS predicted a T-Index of
+5 for
Australia for the month
of December 2007.
Compare the IPS predicted Australian T-Index of -40 for 27 Dec 2007.
IPS posts a single T-Index in the reports normally available to us. To us, this seems
to cover a very wide geographical area. (note the individual geographical areas included in the section of this
report immediately below). A precedent may have been established with the Kp-Index.
MUFs:
Equatorial PNG/Niue Region:
Depressed by 20% over UT day.
Northern Australian Region:
Depressed by 20% during local day,
Near predicted monthly values during local night.
Southern Australian and New Zealand Region:
Depressed by 20% during local day,
Near predicted monthly values during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
COMMENT: IPS HF Communications Warning 45 was issued on 23 December
and is current for interval 24-26 December. Depressions of up
to 30% were observed at times across the Australian region over
the past 24 hours, particularly during the local day. Periods
of Sporadic-E were also observed at some mid to low latitude
stations over the past 24 hours which may have affected HF propagation
conditions. Continuing MUF depressions are expected over the
next few days due to very low levels of solar activity, with
significant depressions possible at times.
Credit: IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST
The above data has been edited from the total report for clarity of this example.
The report in its entirety is published below.
SUBJ: IPS DAILY HF PROPAGATION REPORT
ISSUED AT 24/2330Z DECEMBER 2007 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST
1. SUMMARY (24 DECEMBER)
Date T index Conditions
24 Dec -26 Normal
Flares: none.
MUFs:
Equatorial PNG/Niue Region:
Depressed by 20% over UT day.
Northern Australian Region:
Depressed by 20% during local day,
Near predicted monthly values during local night.
Southern Australian and New Zealand Region:
Depressed by 20% during local day,
Near predicted monthly values during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
PCA Event : No event.
Predicted Monthly T index for December: 5
2. FORECAST (25 DECEMBER - 27 DECEMBER)
Date T index Conditions MUFs
25 Dec -32 Normal 10 to 30% below predicted monthly
values
26 Dec -35 Normal 10 to 30% below predicted monthly
values
27 Dec -40 Normal 10 to 30% below predicted monthly
values
COMMENT: IPS HF Communications Warning 45 was issued on 23 December
and is current for interval 24-26 December. Depressions of up
to 30% were observed at times across the Australian region over
the past 24 hours, particularly during the local day. Periods
of Sporadic-E were also observed at some mid to low latitude
stations over the past 24 hours which may have affected HF propagation
conditions. Continuing MUF depressions are expected over the
next few days due to very low levels of solar activity, with
significant depressions possible at times.
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More Propagation Data for Australia
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The Following Definition is from The Web Site's Glossary
T Index : The "T-Index" is a value that shows the relative effect that solar activity is playing on high frequency radio wave propagation. The measured effect reflected in the T-Index's value is dependent on the degree of ionization in the F Region of the ionosphere. The "Index" is an indicator of the Maximum Usable Frequency (HF). The Index serves an additional role in that it expresses propagation relative a given UTC day's position in the 11-year solar cycle.
The higher the value for the T index :: the higher the Maximum Useable Frequency (MUF). True, but nothing too special about the comment. For the T-Index to have real meaning, it must express something other than an expectation of value for the MUF. There must be something else to it- and there is. Below is a brief discussion of the added value obtained through having knowledge of how the Index relates to changing propagation during the course of the 11-year solar cycle.
The T index varies with the progress of the Sun in the current solar cycle. The Index gives meaning to the term "normal propagation". Propagation is based on what is considered "normal" for a given day's position in the solar cycle. "Normal propagation" for a day near solar minimum would be well "below normal propagation" if the day being discussed occurred during a time approximating "solar maximum". A forecast that states "normal propagation" but is devoid of qualifiers as to what can be considered normal falls short of being very helpful. A ham with long experience operating on 20-meters might know the meaning of normal propagation during times near solar minimum. A ham short of experience can only guess its meaning.
Other solar indices do not follow the 11-year solar cycle in the same way as the T-Index. The T-Index gives propagation descriptions such as "NORMAL", "FAIR" and "POOR" more meaning since it takes into account a given UTC - day's position in the 11-year solar cycle.
When a term for propagation such as "NORMAL" is used without giving a T-Index value (a reference value), the nowcaster or forecaster should include a statement along the lines of:
High Frequency (HF) propagation in the middle latitudes is expected to be "normal" for the current UTC-day - at this UTC-day's position in the 11-year solar cycle. Emphasis KC4COP
When the T-Index is quoted, the current position in the 11-year solar cycle is assumed - by definition.
It is the Webmaster's belief that the UTC-day's position in the 11-year cycle should be stated in a nowcast or forecast (without this information studying trends in archived data is made more difficult). In truth, the above statements are rarely included in most statements of nowcasting and forecasting that use the terms: "normal", "poor", "fair", etc.
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This Report is issued Directly to KC4COP ( www.zseltvay.com) by The Australian Space Forecast Center's Radio and Space Services. The spirit of ham radio includes sharing information with others that participate in the hobby. www.zseltvay.com re-publishes solar and geophysical information for the benefit of all amateur radio operators.
The www.zseltvay.com Web Site is mirrored at www.kc4cop.bizland.com