continuous movement of water through Earth's systems
stages: evaporation, condensation, precipitation, runoff, collection
driven by solar energy and gravity
evaporation from oceans and land surfaces lifts water into the atmosphere
condensation forms clouds, precipitation returns water as rain, snow, sleet, hail
runoff flows through rivers and streams to lakes and oceans
groundwater infiltration recharges aquifers through soil and rock
transpiration from plants returns water to the atmosphere
the cycle purifies water, distributes heat, and shapes biomes
connected to carbon cycle and nitrogen cycle through dissolved transport
glaciers and ice caps store 69% of Earth's freshwater