A local high school student, Sahana Rao, from Centreville High School recently won science fair at the school-based level and moved on to Fairfax County Regional Science & Engineering Fair that took place on March 15-17, 2013. More information about this year’s Science Fair can be found on the Fairfax County Public Schools Science Fair Website: http://www.fcps.edu/is/science/sciencefair/
This experiment uses space weather forecasts made by participants, with various levels of experience, in a space weather forecasting contest to compare consensus and individual forecasters in regards to accuracy.
The primary drive of space weather is solar wind emitted from the sun which is composed of nearly fully ionized particles released from the sun into interplanetary space. Major space weather events that modify solar wind include coronal mass ejections, geomagnetic storms, solar radiation storms, and radio blackouts. Space weather indicators are predicted daily by NOAA’s Space Weather Prediction Center, but can be estimated by anyone using solar wind measurements and from previous forecasts.
The forecasts used in this experiment consist of three values. The electron flux values measure the amount of electrons coming from the sun in solar wind. The Planetary K index or Kp, represents the activity of the Earth’s magnetic field on a scale with 9 values. The solar wind velocity measures the speed of solar wind coming from the sun.
The purpose of this experiment is to compare the forecasts made by individual users to the consensus forecast for accuracy. Consensus collaboration for greater accuracy was noted by Francis Galton in 1907 in the Nature magazine . In the article, Galton surveyed many people on the weight of a certain cattle, some of who had knowledge on the weight of cattle and some who didn’t. His results displayed the consensus or ‘vox populi’ with a lower probable error than the individual estimators. The main drive for comparing accuracy using a consensus in this experiment is to note if similar results would arise when forecasting space weather.
It is important that space weather is accurately forecasted, as it can have many dangerous effects on the Earth. For example, space weather events such as solar radiation storms and geomagnetic storms expose astronauts and even passengers in commercial airplanes to a large amount of radiation. Spacecrafts and satellites can be damaged by the charged particles and plasma in solar wind. Space weather storms can also cause power outages and disruption of radio signals here on Earth. Accurate space weather forecasts are important, because many of these effects can be mitigated if we know ahead of time.
In this experiment, 30 different forecasters around the world with various levels of knowledge of space weather have forecasted the 3 space weather indicators for 101 days. Using the programming software MATLAB, their data is compared to the verification, or actual measurements for that day. The consensus forecast was compiled by averaging all of the forecaster’s forecasts. The consensus forecast is then also compared to the individual forecasters to see which had greater accuracy. The number of days forecasted, the method used to compare forecasts, the programming platform used, the space weather values, and the source of the data files are kept constant in this experiment.
The hypothesis is that if all forecasts are combined then the forecasts will be more accurate. This is because the consensus forecast will be an average of all the individual estimates which would reduce the outliers in the individual user’s data. The consensus should be closest to accurate compared to any of the other forecasts.
To take a look at Sahana’s full Research Report, click here.