Ocean Currents

Answers

Quandary of two Russian ports:   Why is the Arctic port of Murmansk ice free all year when ports near St Petersburg much further south are surrounded by ice for more than a month each year? Answer:   The seas near Murmansk are warmed by relatively warm Atlantic water that flows into the Barents Sea via the Norwegian Current and North-Cape Current. The Baltic has no such influx of warm water, so it is much colder in winter.