2
The
on Earth
water is circulating atmosphere, continen
today as in the d
Also, between the P lanet’s four grea system of exchan ge processes is at w sphere : a permanen t ork.
The same ays of our ances tors! t reservoirs : oce ans, tal waters and bio
2
3
1
The ocean currents transport water and heat. The oceans therefore have a great influence on climate, which is defined as the average weather in a given place. The climate of a region is determined using statistical methods for processing measurements such as sea and land temperatures, wind characteristics, or precipitation.
The atmosphere carries humidity from regions where water evaporates towards the areas where it condenses and changes into rain.
The precipitation also feeds the groundwater tables which, like the river systems, transport water to lakes or oceans.
4 The sun is the driving force behind the hydrological cycle. Its energy activates the various systems that ensure water’s transport in the ocean and the atmosphere.
Water renewal in the atmosphere and the various water courses happen quickly, in just one or a few weeks. Yet in lakes water can stay for decades and in oceans, glaciers and in certain groundwater systems for several thousand years.
sun
4
2 atmosphere precipitation: rain, hail, snow condensation evaporation meltwater lakes evapotranspiration oceans
1 continental shelf
3 rivers and runoff waters infiltration groundwater