Changes in the Radioactivity Regime during the Passage of a Cold Front over The Netherlands

Abstract

Artificial radioactivity in rainwater was measured during the passage of a cold front over The Netherlands. The specific radioactivity of the frontal rain increased considerably after the frontal veering of the wind. Concurrently the “age” of the fission products decreased from 45 to 17 days, indicating a supply of atomic debris from recent nuclear explosions in arctic regions. The specific radioactivity of the air increased considerably on the day of the frontal passage. Trajectories of pre-frontal and post-frontal air indicate that the pre-frontal air comes from a source region in the Mediterranean and the post-frontal air from the arctic regions. The diagram of the frontal passage is analysed.