Tracking Solar Flares
Tracking Solar Flares Space Weather Monitors The Ionosphere Activity Resources Glossary

Tracking Solar Flares Activity

Everyone who completes this activity and sends us a valid report will receive a certificate acknowledging your contributions to solar research!

  1. What you Have to Know
  2. Pick a flare to search for
  3. See if your flare impacted the Earth's ionosphere
  4. Learn the history of your flare’s active region
  5. Send us your Solar Flare Report Form


Step 1: What you are going to be doing in this activity is looking at real scientific data, both collected by other students and by scientists, to try to find evidence of solar flares that have impacted our ionosphere!

Read below about how the Sun sends high-energy rays to the Earth and how those rays affect the Earth's ionosphere (the upper atmosphere directly above your head). No, there won't be a test. But it will help you understand your data if you understand what it is measuring!
Then watch a video of the biggest flare ever recorded on the Sun!

What you have to know to do this activity -- Background

Solar flares imaged by the TRACE satellite.
Solar flares imaged by the TRACE satellite.
Photo courtesy NASA.

The Sun spews out a constant stream of X-ray and extreme ultraviolet (EUV) radiation. This energy, along with that from cosmic rays, affects the Earth’s ionosphere, starting some 60 km above us. When solar energy or cosmic rays strike the ionosphere, electrons are stripped from their nuclei. This process is called ionizing, hence the name ionosphere. It is the free electrons in the ionosphere that have a strong influence on the propagation of radio signals. Radio frequencies of very long wavelength (very low frequency or “VLF”) “bounce” or reflect off these free electrons in the ionosphere thus, conveniently for us, allowing radio communication over the horizon and around our curved Earth. The strength of the received radio signal changes according to how much ionization has occurred and from which level of the ionosphere the VLF wave has “bounced.”

The Earth’s ionosphere and reflecting of VLF radio waves.
The Earth’s ionosphere and reflecting of VLF radio waves.
Image courtesy of Morris Cohen, Stanford University

The ionosphere has several layers created at different altitudes and made up of different densities of ionization. Each layer has its own properties, and the existence and number of layers change daily under the influence of the Sun. During the day, the ionosphere is heavily ionized by the Sun. During the night hours the cosmic rays dominate because there is no ionization caused by the Sun (which has set below the horizon). Thus there is a daily cycle associated with the ionizations.

In addition to the daily fluctuations, activity on the Sun can cause dramatic sudden changes to the ionosphere. The Sun can unexpectedly erupt with a solar flare, a violent explosion in the Sun's atmosphere caused by huge magnetic activity. These sudden flares produce large amounts of X-rays and EUV energy, which travel to the Earth (and other planets) at the speed of light.

The biggest flare ever recorded on the Sun
Why is the Sun colored green?

When the energy from a solar flare or other disturbance reaches the Earth, the ionosphere becomes suddenly more ionized, thus changing the density and location of its layers. Hence the term “Sudden Ionospheric Disturbance” (SID) to describe the changes we are monitoring and also the nickname of our space weather monitoring instrument, SID.

Read more about how the Sun affects the Earth

Read more about our ionosphere

Watch more videos of the Sun's super flare!

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Step 2: Find a flare that appeared on the Sun by using scientific data and imagery from NASA's Solar Dynamics Observatory, The example will show you how:
Choose your flare and write down:
  • The date and time of the flare
  • The strength of the flare
  • The Active Region where the flare came from (explained in the example)
  • Start a Solar Flare Event Report for us!

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Step 3: Find evidence that your flare struck the Earth
You'll find out if your flare impacted the Earth's ionosphere by looking at the SID Space Weather Monitor data. Our example will show you how:

Stanford University Solar Center's Space Weather Monitors (SIDs) are scientific instruments that track changes the Sun makes to the Earth's ionosphere. SID monitors are placed in middle school, high school, and college classrooms all over the world -- and anyone can access their data! You are going to look through the SID data we've collected to see if you can find solar flares or other exciting astronomical events. Much of this data have never been looked at, so you could discover a real event!

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Step 4: Did your flare's active region start out on the backside of the Sun?

You can trace the history of your flare's active region. The Sun rotates, as does the Earth. It takes about 27 days for the equator of the Sun to rotate around (other latitudes rotate at different rates). Often, the active region that caused your flare started out on the backside of the Sun and rotated into view. And we actually have "images" of the backside ("farside") of the Sun! Want to see if you can find yours?

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Step 5: Submit your Solar Flare Report Form
If you think you've found a solar flare or some other interesting event in the SID data,
Send us a report!

Everyone who sends us a report (and a valid email address) will receive a certificate acknowledging your flare discovery!


Missing flares?

Sometimes a flare will show up in the GOES data graphs but not the catalog. The GOES data is reduced by hand, and often flares are "missed" being added, or they are determined for some reason not to be included in the catalog. If you find flare signatures in your SID data, and if those flares also appear on the GOES graphs, but they are not listed in the catalog, then you may have found flares overlooked or ignored by the GOES cataloger. We would LOVE to hear about that! Please submit a Flare Report Form tell us in the comments section that your flare did not appear in the GOES catalog.

Remember that the GOES satellites are detecting solar flares as they are emitted from the Sun. Your SID monitor is detecting changes to the Earth’s ionosphere caused by those same flares. So while your monitor and the satellites are tracking different effects, they are based on the same phenomena.

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