Variation in the magnetic field at Triton. These results were obtained with the OTD-O8 model from Connerney et al. (1991). (a) Variation in the magnetic field norm over one orbit around Neptune, starting from August 21, 1989. (b) Histogram of the value of the norm of the magnetic field at Triton when the Triton L-shell is lower than 15.5. These results were computed over one period of variation in the magnetic field at Triton, i.e., 35 days, from August 21, 1989.