Water Systems

1. Water Systems

2. Heat and temperature • “hot” – lots of heat energy • “cool” – little heat energy • Something is cold if it will take away heat from its surroundings

3. Heat Capacity • The amount of heat energy that must be added to increase its temperature by 1 degree Celsius

4. Solvents • Solvent – the liquid doing the dissolving • Solute – the substance being dissolved • Soution – the mixture of solvent with the dissolved solute in it

5. What is salt? • Any mix of acids and bases (an anti-acid) • Acids – lemon juice, coffee, vinegar, battery acid • Base – baking soda, ammonia, soapy water, bleach, drain cleaner • Table salt, Epsom salt, road salt, metal salts that change the colour of fireworks, gunpowder

6. Salt water evaporation • When water evaporates, dissolved minerals stay behind • Water vapour is mostly pure water

7. If rainwater is fresh water, why are the oceans getting saltier? • Dissolved rainwater weathers and erodes minerals as it runs down to the oceans and seas • The minerals dissolve in the water

8. Hard and soft water • Soft water has few minerals dissolved in it • Hard water is saturated with magnesium (Mg) and calcium (Ca) • You want soft water running in your house • Doesn’t react well with soap = no suds or bubbles • Won’t build up deposits in your pipes • People ‘soften’ their water with sodium salt, which kicks out the harsh Mg and Ca

9. Convection Cell • What are the global sources of heat, and the global sources of cool

10. Ocean currents • Lots of nutrients and oxygen comes from aquatic plants and decaying organic material • Get stirred up to surface by convection currents • Cold water = nutrient rich water • Half of the world’s fisheries are supported by these upwellings • Current is a movement in the water • Circular pattern of flow of ocean water called a gyre • A mix of several currents in different directions

11. Hot water meets air • Hot water heats the air above it • Hot air contains more moisture • Hot air rises, cools in upper atmosphere, and loses its moisture

12. High and low pressure • Hot air rises – low pressure system • Usually comes with cloudy weather and • Cold air sinks – high pressure system • Clear skies • Air always moves from high to low pressure

13. Wind • Sun shines on Earth, even heating of land and water, but different heat capacities • Means different temperature changes

14. Shortest distance between two points is… • A Straight line

15. Why do flight paths look so curved • Shorter distance at poles to travel • What about going straight north/south

16. Coriolis ‘Force’ • All things move in straight lines • Earth spins, makes objects moving in straight lines appear to curve • **There is no force pushing winds or currents in circles • Results in circular patterns to moving wind and water • CW in the Northern hemisphere • CCW in the Southern hemisphere

19. Weather vs. Climate • Weather is the present or day to day precipitation, wind, temperature, air pressure • Climate is the long-term pattern in atmospheric pressure, temperature, humidity, wind, and precipitation

20. Ocean currents, wind, and climate • Ocean currents moving away from Equator warm the air above them • More moisture/precipitation • Low pressure • Warmer air temperatures • Winds blow this air over the land

21. What is a desert?

22. Desert formation • Ocean currents moving away from the Poles are cold • Cool air over it, which then loses its moisture (as fog usually) • When this dry air blows over land, sucks up the moisture, creating dry climates • Dry, cold, descending air also creates dry, high pressure climates

23. West coasts and ‘horse’ latitudes = deserts