Check out the ACE-HF propagation software - the latest is version 2.05. ACE-HF is propagation forecasting and modeling for Amateur Radio as well as for Shortwave radio Listening and general HF operation. This software is even used by the military and other clients around the world. This software is developed and maintained by the same engineers that keep VOACAP up-to-date. As a result, this software is the most accurate user interface integrated with VOACAP. CHECK IT OUT, TODAY. This software is the most accurate modeling software available, and is endorsed by NW7US. Read the details to find out why.
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Map, Above: Conditions in the D region of the ionosphere have a dramatic effect on high frequency (HF) communications and low frequency (LF) navigation systems. The global D Region Absorption Predictions (D-RAP) depicts the D region at high latitudes where it is driven by particles as well as low latitudes, where photons cause the prompt changes.
Note: At times, images may appear broken or missing, when SDO is working on the AIA/HMI instruments.
Planetary A-index (Ap): 8
| Planetary K-index (Kp): 3
Solar Wind: 496 km/s at 5.0 protons/cm3, Bz is -3.0 nT
(Sep 20, 2017 at 0346 UT)
Here is a video introduction to shortwave / HF amateur radio -- what is it that we amateur radio oprators listen to? If you have not yet been introduced to this world, this is a very basic introduction.
If you are using software utilities such as Ace-HF, that require a "smoothed" sunspot number
(Referred to as the SSN), or, the smoothed 10.7-cm Radio Flux Index,
use the following predicted values in this following table:
Predicted SMOOTHED Sunspot Number And Radio Flux Values
With Expected Ranges
At 0805 UTC, on 9 August 2011, a strong magnitude X6.9 X-ray flare -- the strongest yet in this current solar cycle (Cycle 24) -- erupted on the northwestern solar limb. Here is a HD Movie of the event:
Videos of Interest - Space Weather, Solar Dynamics Observatory, STEREO, and more... from the NW7US YouTube Channel. (Click on the small image to launch the video...)
Video: Voyager Finds Magnetic Foam at Solar Systems Edge
Video: Zoom View of Prominence Eruption and X-Ray Flare - M2.5 Magnitude - June 7 2011
Video: X-Ray Flare, Coronal Mass Ejection, Proton Storm - M2.5 Magnitude - June 7 2011 (Close-up of the video, above)
Video: Stunning Close-up View of M3 X-Ray Flare 24 February 2011
Video: June 2011 20-meter (14-Mhz) JT65A Coverage Map of NW7US Radio Signal
The NW7US Current Sunspot and Geophysical Activity Report
The observations, prognastications, and comments by NW7US
NW7US is Tomas David Hood, Propagation and Space Weather Columnist
for CQ Communications
More about Background X-rays
The hard X-ray energy present from the wavelengths of 1 to 8 Angstroms provide the most effective ionizing energy throughout all of the ionospheric layers in our atmosphere. The GEOS satellites measure these wavelengths and the resulting measurements are reported as the "background X-ray level" throughout the day. A daily average is reported, as well.
Just like X-ray flares, the background hard X-ray level is measured in watts per square meter (W/m2), reported using the categories, A, B, C, M, and X. These letters are multipliers; each class has a peak flux ten times greater than the preceding one. Within a class there is a linear scale from 1 to 9.
If one records the daily background X-ray levels for the course of a sunspot cycle, one would discover that the background X-ray levels remained at the A class level during the sunspot cycle minumum. During the rise and fall of a solar cycle, the background X-ray energy levels remained mostly in the B range. During peak solar cycle periods, the background energy reached the C and sometimes even M levels.
Armed with this information, can we discover any clues as to the current status of Sunspot Cycle 24? Below is a graph plotting the background hard X-ray energy reported by the GEOS satellites since the end of Sunspot Cycle 22. Clearly, we see a noticeable rise in Cycle 24 activity. We're seeing the energy mostly in the B level more often, supporting the view that Cycle 24 is alive and moving along toward an eventual sunspot cycle peak in several years.
Overall, the monthly average background 'hard' X-ray level is rising (as seen by the following plot), showing a change from deep solar cycle minimum. We are certainly in the rising phase of Sunspot Cycle 24. While it has been a slow up-tick over the last eighteen months, I expect to see a more rapid rise during mid to late 2011.
Highlights of Solar and Geomagnetic Activity
Covering the period: 11 - 17 September 2017
Solar activity was at predominately very low levels through the summary period, interupted by a brief period of low activity on 12 Sep as Region 2680 (N09, L=317, class/area Hsx/140 on 12 Sep) produced a pair of impulsive C-class flares. 11 Sep saw the X-ray background elevated at the C-level due to slow decay from the X8 flare (R3-Strong) observed at 10/1606 UTC. No Earth-directed CMEs were detected during the period.
Of note, two halo CMEs were observed on 17 Sep. The first one, a full-halo CME, was first observed in LASCO C2 imagery at 17/1224 UTC, while the second one was a partial-halo CME, first observed in LASCO C2 imagery at 17/1424 UTC. The source region of both CMEs was determined to be from old active Region 2673 (S09, L=119) which is presently on the back side of the solar disk. Old Region 2673 is due to return on 23 Sep.
10 MeV and 100 MeV protons at geosynchronous orbit exceeded their respective event thresholds during the period, both in response to the X8 flare observed on 10 Sep. At 10/1645 UTC, 10 MeV protons exceeded 10 pfu (S1-Minor), reached a maximum of 1,490 pfu (S3-Strong) and decayed below the S1 level at 14/1725 UTC. The 100 MeV proton flux exceeded the 1 pfu level at 10/1625 UTC, reached a maximum of 68 pfu at 10/2215 UTC and ended at 13/0335 UTC.
The greater than 2 MeV electron flux at geosynchronous orbit was at moderate levels on 13-14 Sep and high levels on 11-12 and 15-17 Sep. A maximum of 46,263 pfu was observed at 17/1610 UTC.
Geomagnetic field activity was a quiet to minor storm levels (G1-Minor) and major storm levels (G2-Moderate) during the summary period. Quiet to unsettled levels were observed on 11 Sep through late on 12 Sep due to waning effects from a negative polarity CH HSS. Late on 12 Sep through midday on 13 Sep, field activity increased to active to minor storm levels (G1-Minor) in response to CME effects from the 10 Sep X8 flare. During this timeframe, total field peaked at 16 nT, the Bz component reached a maximum southward extent of -12 nT and solar wind speed peaked at about 650 km/s. Quiet levels were observed for the remainder of 13 Sep through midday on 14 Sep.
From midday on 14 Sep through 17 Sep, field activity was dominated by effects from a recurrent, positive polarity CH HSS. Unsettled to G1-Minor and G2-Moderate levels were observed through 16 Sep with quiet to active levels present on 17 Sep. During this timeframe, total field peaked at near 22 nT, the Bz component reached a maximum southward extent of -18 nT and solar wind speed peaked at about 775 km/s.
Monthly and smoothed sunspot number - The monthly mean sunspot number (blue) and 13-month smoothed monthly sunspot number (red) for the last five cycles. You can see that this current cycle, Cycle 24, is a weak cycle, compared to the last few.
(Click to see actual size)
Daily and monthly sunspot number (last 13 years)
Daily sunspot number (yellow), monthly mean sunspot number (blue), smoothed monthly sunspot number (red) for the last 13 years and 12-month ahead predictions of the monthly smoothed sunspot number:
SC (red dots) : prediction method based on an interpolation of Waldmeier's standard curves; It is only based on the sunspot number series.
CM (red dashes) : method (from K. Denkmayr and P. Cugnon) combining a regression technique applied to the sunspot number series with the aa geomagnetic index used as a precursor (improved predictions during the minimum phase between solar cycles).
(Click to see actual size)
What is 'Space Weather'? Click on these two information slides to view them in full size:
Solar Flares: Quiet conditions (<50% probability of C-class flares) Geo-Disturbance: Quiet (A<20 and K<4) Solar Proton Event: Quiet
Comment from the SIDC (RWC Belgium): Over the past 24 hours the solar activity was very low with no flaring activity recorded. The Catania sunspot group 55 (NOAA active region 2680) is the only present region on the disc, and is unlikely to produce any flaring activity. We expect the solar activity to remain quiet until the returning region (Catania sunspot group 49 / NOAA active region 2676) will come from behind the East solar limb by the end of the day.
Three Day Forecast of Solar and Geomagnetic Activity
(as of 2200Z on 07 Dec 2014)
Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (08 Dec, 09 Dec, 10 Dec).
The geomagnetic field is expected to be at quiet to minor storm levels on day one (08 Dec), quiet to active levels on day two (09 Dec) and quiet levels on day three (10 Dec).
Forecast of Solar and Geomagnetic Activity
18 September - 14 October 2017
Solar activity is expected to be at predominately very low levels on 18-22 Sep and 08-14 Oct. R1-R2 (Minor-Moderate) levels are expected on 23 Sep-07 Oct due to the return of old Region 2673 (S09, L=119).
The greater than 10 MeV protons at geosynchronous orbit are expected to remain at background levels from 18-22 Sep and 08-14 Oct. A chance for an S1-S2 (Minor-Moderate) proton event is possible from 23 Sep-07 Oct in association with significant flare activity after the return of old Region 2673.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 18-22 Sep, 28 Sep-19 Oct and 12-14 Oct due to CH HSS influence. Normal to moderate levels are expected for the remainder of the outlook period.
Geomagnetic field activity is expected to be at unsettled to active levels on 18-20 Sep, 24-25 Sep and 30 Sep-02 Oct with G1 (Minor) storm conditions possible on 27-29 Sep and 11-14 Oct due to recurrent CH HSS activity. Mostly quiet conditions are expected for the remainder of the outlook period.
Be sure to check the Date shown in each photo - is it today's date?
(click to enlarge)
Check out these books on Radio Propagation:
+ The New Shortwave Propagation Handbook (Paperback) - by George Jacobs, Theodore J. Cohen, R. B. Rose. The NEW Shortwave Progagation Handbook may well be the only book you'll need on the subject of ionospheric propagation! It is a "must read" for Radio Amateurs, Shortwave Listeners, and radio communicators of any type who need to make the most productive use of the radio spectrum, regardless of the time of day, the season of the year, or the state of the sunspot cycle. It will become your ever-present companion a the operating table as you master the art of shortwave radio progagation.
+ How Radio Signals Work (Paperback) - by Jim Sinclair. This book provides a basic understanding of the way radio signals work-without becoming bogged down with the technicalities. It covers all kinds of radio signal types--including mobile communications, short-wave, satellite, and microwave. No detailed knowledge of electronics or mathematics is required. A-Z coverage of radio signals including satellites, mobile communications, and short-wave radio. No math or electronics background necessary.
+ Introduction to RF Propagation (Hardcover) - by John S. Seybold. This book provides readers with a solid understanding of the concepts involved in the propagation of electromagnetic waves and of the commonly used modeling techniques. While many books cover RF propagation, most are geared to cellular telephone systems and, therefore, are limited in scope. This title is comprehensive-it treats the growing number of wireless applications that range well beyond the mobile telecommunications industry, including radar and satellite communications.
Data and images courtesy of IPS Australia, NOAA, NASA, SWPC, SIDC
Layout, analysis, commentary, and certain forecasts and content is Copyright, 2017, Tomas David Hood (NW7US), all rights reserved.
No part, except for the space weather 'banners', may be copied without express permission.