Water, Wind and Weather How it all works

Remember the spheres around us What are they called? Lithosphere The lithosphere contains all of the cold, hard solid land of the planet's crust, land underneath the crust, and the liquid land near the center of the planet. Biosphere The biosphere contains all the planet's living things. Hydrosphere The hydrosphere contains all the solid, liquid, and gaseous water of the planet Atmosphere The atmosphere contains all the air in Earth's system.

Atmosphere When air temperature in the lower portion of this sphere changes, weather occurs. As air in the lower atmosphere is heated or cooled, it moves around the planet. The result can be as simple as a breeze or as complex as a tornado. 

The Hydrosphere A small portion of the water in the hydrosphere is fresh (non-salty).  Most of Earth's fresh water, however, is frozen.  97% of Earth's water is salty Water near the poles is very cold, while water near the equator is very warm. The differences in temperature cause water to change physical states.

What is all this weather?

Hydrologic Cycle evaporation transpiration condensation precipitation runoff

Evaporation Change of state in a substance from a liquid to a gas. energy is required. the sun, the atmosphere, the earth, or objects on the earth such as humans. Humans evaporate: think sweat!

Transpiration Transpiration is the evaporation of water from plants  Of the transpired water passing through a plant only 1% is used in the growth process of the plant. The remaining 99% is passed into the atmosphere.

Condensation Water vapor in the atmosphere is changed into a liquid state. may appear as clouds or dew. water appears on the side of a cold drink can. Condensation is not a matter of one particular temperature but of a difference between two temperatures. Foggy conditions often occur when air temperature and dewpoint are equal. Condensation is the opposite of evaporation. Since water vapor has a higher energy level than that of liquid water, when condensation occurs, the excess energy in the form of heat energy is released.

Precipitation Precipitation is when the tiny condensation particles grow too large for the rising air to support, and then fall to earth. Precipitation can be in the form of rain, hail, snow or sleet. Precipitation is the primary way we receive fresh water in earth.

Runoff Excessive precipitation and the ground cannot absorb anymore water. Rivers and lakes are results of runoff. for the most part water in rivers and lakes return to the oceans. If runoff water flows into a lake only, then evaporation is the only means for water to return to the atmosphere. only pure water evaporates, the result is the lake becomes salty like the Dead Sea in Israel. Evaporation of this runoff into the atmosphere begins the hydrologic cycle over again.

The Wonderful World of Wind! The atmosphere is composed of air Air is made up of nitrogen, hydrogen and oxygen gases The sun shines on our atmosphere all of the time But, It heats the surface of the earth unevenly This means that in some places it’s warm and some places it’s cold. What does this do???

Wind Cont’d As air gets warmer, it’s particles spread out This makes the air lighter or less dense so it rises As air cools, it’s particles get closer This makes the air heavier or more dense so it sinks As warm air rises, air from cooler areas flows in to take the place of the heated air. This process is called CONVECTION and causes air to move… creating WIND

Example from Everyday Life Sea Breeze and Land Breeze: Coastal winds blow landward during the day and seaward at night… but why? On a sunny day, the sand warms quickly The warm air over the beach rises So, the cool ocean air moves in to replace it Causing a Sea Breeze (coming from water to land)

Demos Wind serpent Convection current