Perpustakaan Digital ITB

Solar activities generate electromagnetic waves and energetic particles in great intensity that could be radiated towards the Earth. Such activity would influence the space environment around the Earth. One of the solar activities that constantly monitored is solar flare. Radiation from solar flare could affect the operational system of many satellites, decrease the intensity and accuracy of navigation and communication signal, and at some cases would disable electrical grid on Earth’s surface. Therefore, monitoring and prediction model of solar flare continuously developed to mitigate the negative effect. Many prediction model use other solar activities as data input, one of which is sunspot. Sunspot formed in areas that have strong local magnetic activity, which corresponds with magnetic reconnection process that trigger the solar flare. One of sunspot’s parameter that can be used in prediction is sunspot’s fractal dimension, which represent the complexity of the sunspot structure, thereafter the energy and magnetic field that contained in that area. This research will analyze sunspot fractal dimension to serve as input in solar flare prediction. Solar image from SDO HMI Intensitygram will be used as primary data to determine the fractal dimension. Then solar image from ground based observatory (PRA Bandung and BPAA Sumedang) will be used to compare the difference between space and ground based data. FIJI and FracLac are used to process the solar images and the sunspot fractal dimension. Values for sunspot fractal dimension that obtained in this research are around 1.25 - 1.5 (regular box counting method) and 1.35 - 1.65 (multifractal method), with positive correlation between fractal dimension and X-Ray flux. Sunspot fractal dimension also affected by sunspot’s morphology and evolution.