N5PA Propagation Page

Solar Indicies
Solar Flux: 75Sunspot#: 0HF IndicatorsVHF Indicators
A-Index: 8K-Index: 2BandDayNightItemStatus
Geomag Fld: QUIETSig Noise: S1-S280m-40mFairGoodAurora: Band Closed
MUF: 8.87MHzSolar Wind: 364.330m-20mFairFair6m EU Es: Band Closed
Flare Class: B1.0 Proton Flux: 0.2317m-15mPoorPoor4m EU Es: Band Closed
Electron Flux: 69.10Magnetic Fld: 5.012m-10mPoorPoor2m Eu Es: Band Closed
2m NA Es: Band Closed

XRay Flare Class: B1.0    Small
Geomagnetic Field: 2   Quiet

Space Weather Overview

Space Weather Overview

Space Weather Alerts and Warnings Timeline
Space Wx Alerts

Latest Observations from the ACE Spacecraft

SW_Density SW_Speed SW_Pressure SW_Temperature IMF_Magnitude
IMF_Polar_Angle Avg_Azimuth Degrees Dawnward of Antisunward Convection Thermal_Energy Log-(Beta)
Sound_Speed Mach_Number Alfven_Speed Alfven_Mach

Low Energy Electrons & Protons - Electron Proton Alpha Monitor (EPAM)


Low Energy Electrons - Electron Proton Alpha Monitor (EPAMe)


Low Energy Protons - Electron Proton Alpha Monitor (EPAMp)


Magnetic Field


Plasma - Solar Wind Electron Proton Alpha Monitor (SWEPAM)


Magnetic Field & Solar Wind Electron Proton Alpha Monitor (SWEPAM)


High Energy Protons - Solar Isotope Spectrometer (SIS)


Latest Picture of Sun
Latest Picture of the Sun
      SDO/HMI Continuum Image
SDO/HMI Continuum Image
Click for SOHO EIT 193 of the Sun
      Solar Synoptic Map
Click for Solar Synoptic Map
HMI Magnetogram
Click for HMI Magnetogram image of the Sun
      AIA 211
Click for AIA 211 image of the Sun

Solar Cycle Progression
Solar Cycle Progression
      Click Here For Solar Indices by Month
Solar Cycle 10.7cm Radio Flux Progression
Solar Cycle 10.7cm Radio Flux Progression
      Solar Cycle Ap Progression
Ap Progression
Satellite Environment Plot
Satellite Environment Plot - 3 days, 5-min data
      GOES X-Ray Flux - 6 hours/1 min
GOES X-Ray Flux - 6 hours, 1-min data
GOES X-Ray Flux - 3 days/1 min
GOES X-Ray Flux - 3 days, 1-min data
      GOES Proton Flux - 3 days/5 min
GOES Proton Flux >10, >50, >100 MeV - 3 days, 5-min data
GOES Electron Flux - 3 days/5 min
GOES Electron Flux - 3 days, 5-min data
      GOES Magnetometer - 3 days/1 min
GOES Magnetometer - 3 days, 1-minute data
Estimated Planetary Kp - 3 days/3 hourly
Estimated Planetary Kp - 3 days, 3-hourly values
      Boulder-NOAA Magnetometer - 12 hours/1-min
Boulder-NOAA Magnetometer - 12 hours, 1-min data

Near-Real-Time Map of Solar Zenith Angles

Solar Zeneth Angles

Using this Map

This map shows you precisely how high in the sky the Sun is at any location around the world. The contours of this map are given in degrees and refer to the distance the Sun is away from the zenith (or that point directly overhead). A contour labeled 10 degrees would define the regions of the world where the Sun is exactly 10 degrees away from the zenith (or in other words, the Sun would be 10 degrees [or about an outstretched hand-span] away from the point directly above your head). A contour labeled 45 degrees would define regions of the world where the Sun is half-way between the horizon and the zenith. A contour labeled 90-degrees would define all of those regions around the world where the Sun is exactly on the horizon (rising or setting). Contours greater than 90 degrees indicate regions of the world where the Sun is below the horizon.

These maps are very useful for radio communicators for several reasons. First, they can be used to help determine where the sun is rising or setting (notice on this map that the 90-degree contour line is obscured by the thicker gray-colored sunrise/sunset terminator line). They can also be used to help determine the regions of the world where solar-flare related short-wave fadeout's are strongest.

Solar flares result in the attenuation of radio signals if the signals are passing through regions of the ionosphere that are sunlit (indicated by contours that are less than or equal to 90 degrees). The intensity of the attenuation is approximately proportional to the solar zenith angle. A signal that passes through the ionosphere where the solar zenith angle is low (corresponding to the region where the Sun is the highest in the sky) will experience the greatest signal loss. Signals that pass through regions where the solar zenith angle is higher will experience less signal loss (and hence greater signal strength at the receiver). These maps are therefore useful to help diagnose the potential impacts of solar flares on communications.

The map shows the radio auroral zones as green bands near the northern and southern poles. The area within the green bands is known as the auroral zone. Radio signals passing through these auroral zones will experience increased signal degradation in the form of fading, multipathing and absorption.

The radio auroral zones are typically displaced equator ward from the optical auroral zones (or the regions where visible auroral activity can be seen with the eye).

 The great-circle signal path from the Eastern United States to Tokyo is shown along with the distance of the path (in km) and the bearing from the U.S. to Tokyo (in degrees from north).

 If this signal path crosses through the green lines indicating the position and width of the radio auroral zones, propagation will be less stable and degraded compared to if the signal never crossed through the auroral zones. Using your mouse, PROPLAB-PRO will let you plot the great-circle paths and azimuths between any two points while this display is continually updated.

The yellow Sun symbol near the equator indicates the location where the Sun is directly overhead.

The regions of the world where the Sun is exactly rising or setting is known as the Grayline and is shown as the solid gray-colored line that is closest to the Sun symbol.

The second solid gray-colored line defines the regions of the world where the Sun is exactly 12 degrees below the horizon. This line defines the end of evening twilight. Everything inside of this second line is experiencing night-time conditions.

The area between the two lines (shaded a lighter shade than the night-time sector) is known as the grayline and has special significance to radio communicators. Signals which travel inside the grayline region often experience significant improvements in propagation because of the loss of ionization in the D-region as the Sun sets. However, because the higher F-regions of the ionosphere remain strongly ionized for longer periods of time, signals with higher frequencies are able to travel to greater distances with less attenuation when they are within the grayline.

The great-circle path from the eastern U.S. to Japan is also shown with the accompanying distance (in kilometers) and bearing (clockwise from north). Notice how this path may occasionally pass into the influential auroral zones if geomagnetic activity increases or during the night-times.

Auroral Activity Extrapolated from NOAA POES

Northern Hemi Auroral Map
Current Northern hemispheric power input map
Southern Hemi Auroral Map
Current Southern hemispheric power input map

Instruments on board the NOAA Polar-orbiting Operational Environmental Satellite (POES) continually monitor the power flux carried by the protons and electrons that produce aurora in the atmosphere. SWPC has developed a technique that uses the power flux observations obtained during a single pass of the satellite over a polar region (which takes about 25 minutes) to estimate the total power deposited in an entire polar region by these auroral particles. The power input estimate is converted to an auroral activity index that ranges from 1 to 10.

Click here for 160 Meter Propagation

Click here for Real Time VHF/UHF QSO Propagation Map

Click here ON4KST 6 Meter Chat/Propagation Map

Geomagnetic Indices and Conditions

Kp IndexAp IndexGeomagnetic Field ConditionsHF NoiseAurora
00 - 2Very QuietS1-S2None
13 - 5QuietS1-S2Very Low
26 - 9QuietS1-S2Very Low
312 - 18UnsettledS2-S3Low
422 - 32ActiveS3-S4Moderate
539 - 56MINOR StormS4-S6High
667 - 94MAJOR StormS6-S9Very High
7111 -154SEVERE StormS9+Very High
8179 -236SEVERE StormBlackoutExtreme
9300 -400EXTREMELY SEVEREBlackoutExtreme

Kp - Planetary K-index, averaged over past 3 hours and tends to be a measure of current conditions

Ap - Planetary A-index, 24-hour average and represents overall geomagnetic field conditions for the UTC day

HF Noise - Approximate "S-meter" noise level <10 MHz

Aurora- Approximate level of auroral activity

Solar Wind-averages 350-450 km/sec and density <10 p/cm^3 >500 km/sec or high density can trigger geomagnetic activity

Shock Wave- from a solar flare or Coronal Mass Ejection (CME) arrives at the Earth about 55 hours after the solar event.

Solar Flare Classifications

Flare ClassType of FlareHF Radio EffectsResulting Geomagnetic Storm
A Very small None None
B Small None None
C Moderate * Low absorption * Active to Minor
M Large * High absorption * Minor to Major
X Extreme * Possible blackout * Major to Severe

(*) - Conditions cited if Earth is in trajectory of flare emissions

Flare class further rated from 1-9, ex. M1, M2, M3 ... M9

The larger the number, the larger the flare within that class

An X7 - X9 is considered a "Grand daddy" flare. Only a few have occured over the past 30 years, causing total dispruption to communications, huge aurora's, power grid failures, etc.
Radio and x-ray emissions from a flare effect the Earth for the duration of the solar event, usually 30 minutes or less.

Earth is 8 light-minutes from the Sun.

Sunspot/Active Region Classifications

Sunspot Class Description of the Active Region Potential for Flare Activity
Alpha Unorganized, unipolar magnetic fields Little threat, but watched for growth
Beta Bipolar magnetic fields between sun spotsC class flares and possible large M class
Delta Strong, compact bipolar fields between spots High potential for a M or X class major flare Major Flare Alert issued