Looking for Changes in Photospheric Temperature Gradients over Solar Cycle 24 Using Hinode/SP

The intent of this project is to study the effects of the solar magnetic cycle on the thermal structure of the solar atmosphere in the quiet Sun. Using data from the spectropolarimeter onboard the Hinode satellite, four datasets were selected from throughout Solar Cycle 24; all datasets selected were near the disk center and without any obvious magnetic signatures. Using an inversion based on the Milne-Eddington model, a quarter-million pixels were inverted from each dataset, using two different inversion schemes. By inverting the data and analyzing the differences in the inverted parameters between the datasets, we attempt to see if the resolution of the Hinode data combined with a Milne-Eddington approach is able to detect meaningful differences in photospheric structure throughout the solar cycle, primarily the source function and its gradient. Our results so far suggest that more detailed inversion and /or data preprocessing is needed to detect eventual presence of the changes.