Temporal development of the correlation between ozone and potential vorticity in the Arctic in the winters of 1988/89, 1989/90 and 1990/91 - Knudsen, B.; von der Gathen, Peter; Braathen, G. O.; Fabian, R.; Jørgensen, T. S.; Kyrö, E.; Neuber, Roland; Rummukainen, M. (1994)