Rainwater and melted snow and ice that move too quickly to infiltrate the ground become runoff. Runoff replenishes the water on Earth's surface and helps to continue the water cycle. The next step in the cycle — evapotranspiration — returns water to the atmosphere. The Sun causes evaporation by heating liquid water on Earth's surface. Transpiration — the evaporation of water from pores in the leaves of plants — also releases water vapor into the atmosphere.
Rising air currents take water, as vapor, up into the atmosphere; with the water form of "evapotranspiration," which is water transpired or from plants and that has evaporated from the soil. The cooler temperatures in the atmosphere cause it to condense in the clouds, which float around in the air until they fall from the sky as precipitation. Some precipitation falls as snow and can accumulate as hail, where it can stay, as ice crystals, for thousands of years. In warmer climates, snow melts, then warmer spring and summer months, and that water flows into streams and rivers, which eventually return it to the ocean, or into the groundwater, which eventually reach underground purifiers. Over time, the water continues to flow, some to return to the ocean, where the water cycle renews itself.
It absorbs much water vapour from the oceans and land vegetation through evaporation. As this air rises it cools. Eventually the water vapour condenses into clouds and it then creates precipitation. So the equatorial region is both hot and wet. The air rises, then spreads horizontally to the north and south.
• Heat from the sun evaporates water found in the ocean, lakes and rivers. Since impurities are left behind, the water that goes in the atmosphere is cleaner then when it was on earth. • Water also evaporates of the leaves of plants – called transpiration 2. Condensation • This process is the opposite of evaporation – water leaves the vapour state and returns to the liquid state • Lower temperatures favour condensation. • Water droplets formed from condensation that are small remain suspended in the atmosphere in atmosphere in the form of clouds in the sky or fog at ground level.
It turns into a river because of all the water the mountains have and then creates a path. Rivers cause erosion. Runoff from rivers cause rocks to erode. Because of gravity, runoff, and the sediment it has, to move downhill. An example of this sheet erosion.
The demand for freshwater, especially in arid regions, has driven people to create and implement new and more effective ways to remove salt from water. Desalination occurs naturally as part of the hydrologic cycle. The Sun evaporates water from the ocean. The vapor, condensed by cooler air in the atmosphere, forms rain clouds. The rain from these clouds reaches the ground as pure liquid water.
Normal conditions, before El Nino events occur, strong trade winds move surface waters westward. As this occurs the water becomes warmer. When water becomes warmer it causes the air to rise and cool causing torrential rainfall. When El Nino occurs there a warm upper ocean layer, which is poor in nutrients and a cold lower ocean layer, which is rich in nutrients. The cold water is brought when the surface current flows westward in a process known as upwelling.
How carbon in the atmosphere is added to rocks and is gone back through the atmosphere? The movement of carbon between the atmosphere and the lithosphere (rocks) begins with rain. This is where atmospheric carbon combines with water to form a weak acid – carbonic acid – that falls to the surface in rain. The acid dissolves rocks – a process called chemical weathering – and releases calcium, magnesium, potassium, or sodium ions. The rivers then carry the ions on to the sea.
The steam brings hydrogen sulphide gas to the surface and pollutes the air unless controls are instituted. 2. Water contains many salts and minerals capable of causing water pollution. 3. The earth in a geothermal field may subside as the water is pumped out.
The earth has had the same amount of water for millions of years. This is made possible by the water (hydrological) cycle which circulates water, constantly moving and changing from one state to another (solid, liquid, or vapour/gas). The many interactions of the atmosphere, lithosphere, and biosphere are responsible for this transition of forms, although the core power of the first stage of movement is from the energy of the sun. The sun provides energy to first evaporate liquid to vapour, which starts the other processed involved in this cycle: precipitation, condensation, transpiration, runoff and percolation/infiltration. The Earth's system of cycling water is viewed as the continual displacement of water taken from the ocean, transported through the atmosphere, deposited over land, and ultimately fed back to the ocean.