Observed difference between the vertical and horizontal magnetic field gradients in sunspots

International audienceA difference (larger than the measurements uncertainties) was observed between the vertical and horizontal gradients of the magnetic field in sunspots. This difference was observed with multiline recordings achieved with the THEMIS telescope and the HINODE/SOT/SP instrument. The multiline feature corresponds to a depth probing. This difference was already present in the literature, which will be discussed in details. The method for interpreting the spectropolarimetric data in terms of magnetic field will be also detailed