TY - JOUR AU - Léo Bosse, Jean Lilensten PY - 2020// TI - On the nightglow polarisation for space weather exploration KW - polarisation / aurora N2 - We present here observations of the polarisation of four auroral lines in the auroral oval and in the polar cusp using a new ground polarimeter called Petit Cru. Our results confirm the already known polarisation of the red line, and show for the first time that the three other lines observed here (namely 557.7 nm, 391.4 nm and 427.8 nm) are polarised as well up to a few percent. We show that in several circumstances, this polarisation is linked to the local magnetic activity and to the state of the ionosphere through the electron density measured with EISCAT. However, we also show that the contribution of light pollution from nearby cities via scattering can not be ignored and can play an important role in polarisation measurements. This series of observations questions the geophysical origin of the polarisation. It also leaves open its relation to the magnetic field orientation and to the state of both the upper atmosphere and the troposphere. SN - 2115-7251 UR - http://dx.doi.org/10.1051/swsc/2020036 N1 - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=7796), last updated on Mon, 20 May 2024 14:11:35 +0200 ID - LeoBosse2020 ER -