Comparison of the thermodynamic state of the low solar corona in three solar cycles

DIEGO G. LLOVERAS; FEDERICO A. NUEVO; ALBERTO M. VÁSQUEZ

Mendoza

Congreso; 60ª Reunión Anual de la Asociación Argentina De Astronomía; 2017

The solar magnetic activity exhibits a cycle about 11 years long. The last three cycles show a systematic decrease of activity. We present a comparative analysis of characteristic rotations from the last two solar minima (1996 and 2009) and a recent rotation (July 2017) using the Differential Emission Measure Tomography (DEMT) technique. To study the rotations we use data taken by the instruments EIT/SOHO, EUVI/STEREO and AIA/SDO respectively. Combining DEMT with potential extrapolations of the photosferic magnetic field using a Potential Field Source Surface (PFSS) method allows studying the thermodynamic state of the low corona through the magnetic field lines. We make comparisons of the thermodynamic state of the solar corona in selected rotations of the last two solar minima and a recent one, close to the minimum of activity.