Spectroscopic observations and modelling of impulsive Alfvén waves along a polar coronal jet P. Jelínek, A. K. Srivastava, K. Murawski, P. Kayshap and B. N. Dwivedi A&A, 581 (2015) A131 Published online: 22 September 2015 DOI: 10.1051/0004-6361/201424234