This view of the Arctic hydrological cycle shows key linkages among land, ocean, and atmosphere. Quantifying the coupling of these components within the Arctic and to the larger Earth system remains an important yet unresolved research issue. The hydrological cycle is inextricably connected to all biological and chemical processes occurring in the biosphere, atmosphere, and cryosphere. Hydrologic interactions with terrestrial and aquatic ecosystems and their biogeochemistry control all life in the pan-Arctic region.

Image Key:
A = atmospheric boundary fluxes;
B = atmospheric dynamics;
C = landsurface atmosphere exchanges with vegetation and permafrost dynamics;
D = discharge through well-defined flow networks with groundwater and river corridor flow;
E = water cycling and runoff over poorly-organized lowland flow systems;
F = sea ice mass balance and dynamics;
G = estuarine controls on terrestrial/shelf interactions;
H = changes in glacial mass balance and associated runoff;
I = direct groundwater discharge to ocean;
J = Arctic Ocean dynamics and deep water formation;
K = biological dynamics and oceanic food chains;
L = socioeconomic factors.