Proper Orthogonal Decomposition of Solar Photospheric Motions
Vecchio, A.; Carbone, V.; Veltri, P.; Sorriso-Valvo, L.; Lepreti, F.; Straus, Th.; Primavera, L.; Alfonsi, G.
Italy
Abstract
The spatiotemporal dynamics of the solar photosphere is studied by performing a proper orthogonal decomposition (POD) of line of sight velocity fields computed from high resolution data coming from the MDI/SOHO instrument. Using this technique, we are able to identify and characterize the different dynamical regimes acting in the system. Low-frequency oscillations, with frequencies in the range 20 130 μHz, dominate the most energetic POD modes (excluding solar rotation), and are characterized by spatial patterns with typical scales of about 3 Mm. Patterns with larger typical scales of ≃10 Mm, are associated to p-modes oscillations at frequencies of about 3000 μHz.