engleski

PREDICTING CME ARRIVAL TIME AND SPEED WITH DBEM

The Drag-based Model (DBM) is an analytical model that predicts the CME arrival time and speed at Earth or any other target in the solar system. It is based on the equation of motion and depends on certain initial parameters such as CME launch speed, background solar wind speed and empirically derived drag parameter. DBM uses a CME cone geometry that includes CME’s angular half-width and longitude of CME source region as additional input parameters. The main advantage of DBM is a very short computational time (<1 ms) which allowed to develop the Drag-Based Ensemble Model (DBEM) that considers the variability of model input parameters by making an ensemble of n different input parameters to calculate distribution and significance of DBM results. Using such approach, DBEM can determine the most likely CME arrival times and speeds, quantify the prediction uncertainties and calculate the forecast confidence intervals. Recently, a fully operational DBEM web application was integrated as one of the ESA Space Situational Awareness portal services providing an important tool for space weather forecast. Using a simple web interface, the user can enter all input parameters and their uncertainties in order to get the CME arrival time and speed distributions at the target (e.g. Earth) based on several thousand DBM calculations within just few seconds. Recent developments of DBEM will be shown together with validation tests where DBEM is compared with observations and more complex numerical models (e.g. ENLIL).

coronal mass ejections ; interplanetary shocks ; space weather ; forecasts ; models ; Physics - Space Physics

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