Why are there Seasons?

-One rotation of the Earth makes up a day.

 

-One orbit around the sun makes up a year.

 

-The Earth is tilted at a 23.5 degree angle on its axis.

 

-The tilt is always facing the same direction.

 

-Different regions of the Earth have more exposure to the sun than other regions, depending on where the Earth is within its yearly orbit.

 

-The Northern and Southern Hemispheres have opposite seasons.  

 

What is heat transfer?

- The transfer of heat from molecule to molecule.

    ***Heat is always transferred from a hotter substance to a colder substance.

 

 Conduction: The transfer of heat from one substance/object to another substance/object that is in direct contact.

 

 Radiation: The transfer of heat from one substance/object to another substance/object when they are not in direct contact.

 

Convection: The cycling of heat within a fluid (liquid or gas).

 

What is uneven heating of the Earth?

-Sunlight is more direct on some areas of the Earth than others, since the Earth is round and tilted.

 

-Heat energy from the sun (radiation) is most direct at the equator, making for a hot climate.

 

-The poles can get more of the sun's heat energy than the equator (when it is tilted toward the sun), but it is spread out over a greater surface area.  This causes the colder climate at the poles.

 

What is ocean circulation?

-Uneven heating of the Earth's oceans.

 

-The oceans are mostly heated at the equator.

 

-Wind, temperature, and salinity cause these waters to move from the equator to the poles (due to changing densities), like one big conveyor belt. 

 

-The warmer surface waters release heat in the polar regions.

 

-The cooled water sinks to the bottom of the ocean and begins to flow back towards the equator. 

 

-The cooler waters are again heated at the equator.