Jan Mayen - Airfield "Jan Mayensfield"
Air operations at Jan
Mayensfield can be challenging due to difficult weather conditions like low
visibility or Karman wind. Karman wind causes sudden dramatic changes in
wind direction and force. Under certain atmospheric conditions lee-waves and
eddies develope a Karman vortex street in the wake of Jan Mayen.
Karman created by
Karman wind created by Beerenberg. (2277m)
Karman vortex street may extend several hundred kilometer downstream from the
island. Wave lengths range from 1-15 km and the diameters of the eddies are of the order 25 km.
The lee-waves and eddies are caused when airflow is diverted by Jan Mayen's isolated conical mountain Beerenberg, 2277 m
above sea level. Eddies are normally generated in situations with a shallow inversion layer intersecting the mountain below 1800 m. The period of the vortex shedding depends on wind speed and stratification and ranges from 25-100 minutes. The eddy shedding has also been recorded on the island as periodic oscillations in air pressure and shift in the wind direction.
In 1991 a C-130 nearly crashed due to a sudden Karman shift just
Jan Mayensfield was
established in 1961 due to the lack of a useable harbour in combination with
bad weather conditions at Jan Mayen. Every second month the station gets
supplies by plane. Crew-shifts are also done by plane. Today most of the air
transport is done by The Royal Norwegian Air Force and their fleet of
Locheed C-130 Hercules. During the first years aircrafts like
PBY Catalina , Douglas DC4 Skymaster,
Grumman A16 Albatross and
Douglas DC6B were used. Jan Mayensfield is important in
medevac and rescue operations, both for the
Jan Mayen station and for ships that need assistanse. When needed the
airfield also serves as a base for research operations.