DBEM WEB APPLICATION FOR HELIOSPHERIC PROPAGATION OF CMES

Forecasting of coronal mass ejections (CMEs) arrival is one of the major tasks for opera- tional space weather services. The Drag- based Model (DBM) with CME cone geometry 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 that depends on the CME launch speed, background solar wind speed and drag parameter gamma which is derived empirically. The main advantage of DBM is very short computational time (<< 1s) compared to the numerical models (e.g. ENLIL). Recently developed Drag- Based Ensemble Model (DBEM) takes into account the variability of model input parameters by making an ensemble of n different input parameters to calculate a distribution and significance of DBM results. Using such approach, DBEM can determine the most likely CME arrival times and speeds, quan- tify the prediction uncertainties and calculate the forecast confidence intervals. To provide the real- time CME forecast to various users worldwide, DBEM web on-line application was developed. Using a simple web interface, user can enter all input parameters and uncertain- ties to get CME arrival time and speed distributions in very short time, where up to 100 000 DBM runs can be performed in less than one minute.