Coordinated observations of solar prominences can be a challenge to perform, and even more so to analyse.
During international campaigns in 2014 and 2015 we focused on studying tornado-like prominences with a combination of space-based satellites (IRIS, Hinode and SDO) and ground based telescopes (THEMIS, Meudon MSDP).
We measured the magnetic field strength and orientation in these tornado-like structures using the He I D3 line from THEMIS, and studied the prominence plasma behaviour at a range of temperatures using IRIS, Hinode and SDO.
With a robust 2D cross correlation method to co-align data from different instruments, we are able to probe plasma and magnetic properties in the prominence on a pixel-by-pixel basis, allowing for a complete analysis of conditions in the tornado.
We present data from 15 July 2014, wherein we show spectral analysis of the Mg II h and k lines from IRIS, line profile analysis of Hinode/EIS lines, and inversion results from THEMIS.
We also study the relationship between line profile shape and magnetic field for both the Mg II lines and lines observed by Hinode/EIS.
Differences between the observations in optically thick (Mg II, He II, Ca II) and optically thin coronal lines are also investigated.
Mg II profiles show a mixture of reversed and non-reversed profiles in the prominence, with the reversed profiles mostly occurring where the magnetic field is strongest, reaching between 20 and 50 G in some parts.
We measure an unambiguously horizontal magnetic field in these structures, parallel to the limb.