Stores

• Most of water is saline (salt) water stored in oceans - 96.6%
• When glaciers melt the freshwater is lost to the sea.
• Oceanic water contains dissolved salts (alkaline), falling pH is linked to the increase in atmospheric carbon.
• Sea ice - forms when water in the oceans is cooled to below freezing, does not raise sea levels when it melts as it forms ocean water. Eg Ross ice shelf.
• Ice Shelves - platforms of ice that form where ice sheets and glaciers move out into the oceans.
• Ice bergs - chunks of ice that break off glaciers/ice shelves and drift into the ocean.
• Ice sheets - mass of glacial land ice extending more than 50,000 km2, eg greenland ice sheet.
• Ice sheets form in areas where snow that falls in winter does not melt fully over summer. Layers of snow pile up onto thick masses of ice growing thicker and denser as the layers condence.
• Ice Streams - near the coast ice (in ice sheets) moves through relatively fast moving outlets. - as long as an ice sheet accumulates the same mass of snow as it loses to the sea, it remains stable.
• If the greenland ice sheet melted scientists estimate it would make sea level rise by 60 meters.
• Ice caps - thick layers of ice on land smaller than 50,000km2, usually found in mountainous areas, dome shaped and form over the highest point of an upland area, they flow outwards and become a source for glaciers.
• Alpine Glaciers - thick masses of ice found in deep valleys or in upland hollows. Most are fed by ice caps/smaller glaciers.
• In the Himalayas 15,000 alpine glaciers form a unique reservoir supporting rivers providing water to millions in south asian countries.
• Permafrost - ground (soil/rock) that remains at below 0 for 2 or more consecutive years. - most formed during cold glacial periods and has persisted through warmer interglacial periods. Some has begun to melt which releases large amounts of co2/ methane.
• Aquifers are most commonly found in rocks such as chalk and sandstone - they are porous and permeable. Water enters the rocks either directly where they are exposed on the ground or slowly water drains through the overlying soil.
• Soils vary in ability to store/transfer water - this is called the soil water budget.
• The upper level of saturated rock is called the water table - this rises and falls in response to groundwater and abstraction by people. 'recharge' is more water flowing into the rocks.
• Fossil aquifers are aquifers in deserts eg in africa. - they were formed thousands of years ago when the climate of those zones were much wetter.
• Saline aquifers are when salt water has infiltrated the rock - this is often due to over abstraction
• Water will remain in different water cycle stores for different amounts of time
• We only have an estimate of total water on earth, oceans are the largest store of water.
• In permafrost, the top layer may melt in summer (this is the active zone)
• There is a very small amount of water in the atmosphere, if the temperature increases so does the amount of water the atmosphere can hold. Water exists in all three states within the atmosphere
• The amount of water held in each store is determined by transfer processes.
• Climate Change - impacts time water held in each stores. At peak of last ice age 1/3 land was covered in ice and sea levels fell. In warmer periods sea levels rise.
• Cloud formation impacts how long water remains in stores. Varies in global atmospheric circulation model.