Horizontal and vertical differences of temperature during the growing season in the Inarijoki-Teno river valley in Lapland

Abstract

Differences of temperature at ground level were observed in the 220 km­ long valley. Measuring points were sited in cultivated areas 3–26 m above the surface of the river. Observation periods were the beginning and end of the growing season. The risk of frost during the growing season increases quite clearly moving upstream from the lower course of the Teno river to the Inarijoki valley. The temperature on spring nights in fields on upper terraces is 2–4' lower than lower down beside the river but in autumn the situation is reversed. The cold encountered in the upper fields in the spring is caused by cold winds blowing from the fell plateau, which is still partly covered with snow. In the autumn there is no longer any snow and therefore when the cold comes, pockets of cold air form in depressions.