Students Track Disruptive Space Weather in Real Time
Scientists say the potential for a severe solar storm is increasing as solar activity heads toward a cyclical peak in 2013. Solar storms are serious business -- they can damage satellites, cause power outages, and interfere with cell phones and other vital communications.
As the solar cycle approaches its maximum, which occurs roughly every 11 years, a program sponsored by NASA and the National Science Foundation is arming high school and college students with inexpensive monitors that can detect solar flares and other sudden ionospheric disturbances, or SIDs, in Earth's ionosphere. The Space Weather Monitor Program, a project of the Stanford Solar Center, already has distributed about 450 of the SID monitors in more than 40 countries, as well as about 25 research-quality monitors called AWESOME.
To get started, students build an antenna "costing less than $10 and taking a couple hours to assemble," according to the Stanford Solar Center website. Next, they connect the antenna to the monitor and the monitor to a computer, where the data collected can be viewed and uploaded to an online repository.
A teacher's guide contains activities that explain the ionosphere, introduce students to the monitors and the data they collect, and help students find potential solar flares in the data.
How Does It Work?
SID monitors are radio receivers, not unlike the radios in cars, but tuned to a different set of stations.
A radio station transmits electromagnetic waves of a certain frequency (the number of wave cycles passing a given point per unit of time). FM stations transmit at frequencies ranging from 88 megahertz (millions of cycles per second) to 108 megahertz. AM stations transmit at lower frequencies, from 535 kilohertz (thousands of cycles per second) to 1,700 kilohertz.
SID monitors are tuned to a band of frequencies known as "very low frequency," or VLF. VLF waves have frequencies in the range of 3 kilohertz to 30 kilohertz, well past the bottom of the dial of the average car radio. The U.S. Navy uses VLF waves to communicate with its submarines, and it is these same waves that bounce off the ionosphere and back to the monitors.
SIDs and the Ionosphere
Around 40 miles above Earth's surface exists the ionosphere, where the sun's energy is so strong that it breaks molecules apart, knocking electrons free from their nuclei. An atom or molecule missing one or more of its electrons is called an ion. The more active the sun, the more free electrons and ions there are in the ionosphere.
Solar flares -- sudden and powerful releases of energy from the sun -- cause sudden increases in the density of ions in the ionosphere. That, in turn, causes unusual changes in the VLF waves bouncing off the ionosphere and received by the SID monitors. SIDs show as spikes in the VLF signal strength, similar to how earthquakes show as spikes on a seismograph.
A set of activities designed for use with the monitors guides students through identifying solar flares in the SID data, tracking flares back to the sunspots that produced them, and learning about the region of the sun from which the flare originated.
› Space Weather Monitor Program →
› Tour of the Electromagnetic Spectrum →
Dan Stillman/Institute for Global Environmental Strategies