The cryosphere is an integral part of the global climate system with important linkages and feedbacks generated through its influence on surface energy, clouds, precipitation, hydrology, and atmospheric and oceanic circulation. Hydrosphere geophysics examines Earth’s fresh water resources, circulation of fresh and salt water, atmospheric ice, seasonal snow cover, glaciers, lake and river ice, sea ice, and frozen ground. Our Sea ice research covers the whole ice-covered ocean, with the main study region having been the Baltic Sea. Seasonal snow cover work has been made in Finland and Antarctica. Hydrology research group have been working mostly at Northern Europe examining circulation of water, temperature conditions, optical properties and climatology.