Why Time Matters in Solar Wind Forecasting

The sun constantly releases a stream of plasma and magnetic field, known as the solar wind, that fills the solar system. This wind can cause space weather that affects our technology. Scientists use models to predict solar wind conditions a few days ahead. These models rely on observations of the sun's magnetic field. They usually assume the solar wind is steady, using only one snapshot of the sun's corona for their predictions. However, this approach can lead to inaccuracies.In a study, researchers used daily updates of the sun's corona for a year to compare the steady-state model with a time-dependent one. They found that the steady-state method can misrepresent the accuracy of the corona models. It also causes three major issues in space weather forecasting: (1) forecasts based on older data are sometimes more accurate than those using the latest data, (2) forecasts can change dramatically with new observations, and (3) the model doesn't capture enough changes in the magnetic field that guides solar particles to Earth. The time-dependent method solves these problems. It provides a more consistent and accurate picture of the solar wind, which helps in predicting when solar eruptions will reach Earth.