Synoptic and mesoscale atmospheric features over the ice‐covered portion of the Fram Strait in spring

Abstract

Data obtained during the Coordinated Eastern Arctic Experiment (CEAREX) from March 31 to April 20, 1989, from two ice camps in the pack ice region in the Fram Strait have been analyzed. The data show that the total period can be divided into two periods or regimes divided by a transition period. The first period was a radiative type, characterized by very low surface temperatures and low wind speeds. Fairly regular oscillations between southerly and northerly winds were caused by small‐scale disturbances in the surface pressure field, associated with upper level waves of large amplitude. During a transition period toward an “advective weather type” on April 11 a sharp frontal zone passed both ice camps. The front was associated with a small‐scale low which had formed over the ice on the shallow but intense baroclinic zone along the northeastern Greenland coast. Mesoscale vortices of this type may, if numerous enough, affect the horizontal transfer of heat from lower latitudes toward Arctic regions as well as the ice drift through the Fram Strait.