Synoptic maps from two viewpoints

Preparing for maps from SDO/HMI and SO/PHI data

¹ Max Planck Insitut für Sonnensystemforschung (MPS), Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
² Faculty of Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
e-mail: loeschl@mps.mpg.de

Received: 31 January 2023
Accepted: 23 October 2023

Abstract

Context. Over recent decades, various kinds of magnetic synoptic chart products have seen major improvements in observation cadence, resolution, and processing, but their creation is still limited by the 27.27 day rotation rate of the solar surface.

Aims. Co-observation from a second vantage point away from the Earth–Sun line with SO/PHI enables the creation of combined magnetic synoptic maps from observation periods that are significantly shorter than a typical Carrington rotation, and therefore provides a data product with magnetic information that is temporally more consistent.

Methods. We upgraded the SDO/HMI synoptic map pipeline in order for it to be compatible with SO/PHI observations at variable distances and a much lower and variable observation cadence. This enabled us to produce combined magnetic synoptic maps using SO/PHI data taken from the far side of the Sun.

Results. We present a pipeline to produce combined magnetic synoptic maps from simultaneous SO/PHI and SDO/HMI observations. Depending on the orbital position of SO/PHI, our combined synoptic maps can be produced up to 13 days faster than any other comparable data product currently available. This strongly reduces the time-lag between the observations that are used to build the map and thereby provides a more consistent map of the magnetic field across the solar surface.