Meteorological Observations on Jan Mayen

摘要

The climate on Jan Mayen is Polar Marine most of the time. The average annual temperature was 0.8°C for the period 1921-1996, with no clear trend. The average annual precipitation for 1921-1996 was 664.4mm, highest in December (64.8mm), lowest in June (31.5mm) The annual average number of overcast days was 242.0 and the average cloud cover 84.6% for 1922-1996. The annual frequency of fog was 13.7forthe 1956-1996 period. The lowest cloud height was below 100m 6.7% of the time 1956-1996. In the period 1971-1981 the mean sea ice freezing up date was 8 January and melting date 21 April for more than 0 octas.