INSOLATION Here comes the Sun… hehehehehehe

How Does Heat Energy Travel? Heat is a form of energy because it can do work. There are three ways that heat can travel 1.Convection 2.Conduction 3.Radiation

Angle of Insolation Angle of Insolation depends on how high the sun is in the sky. As the sun rises and sets the a.o.i. changes, ie, the daily weather cycle. We measure the a.o.i from the horizon up to the position of the sun. Smaller angle=colder temp Larger angle (90˚)= warmer temps

A.O.I

The a.o.i also works for the seasonal weather cycle. In the Northern Hemisphere, the lowest noon time a.o.i is on Dec. 21 and the highest noon time a.o.i is on June 21. These are different because Earth is spherical. The vertical ray is the most direct amount of insolation (warmer temps), which always hits in the Tropics. All other latitudes received indirect, or slanted amounts of insolation (colder temps).

Duration of Insolation Duration of Insolation is the length of time from sunrise to sunset. When Earth has a greater duration of insolation, the temperatures increase. Direct Relationship D.O.I varies greatly with latitude. Higher the latitude, the more extreme amounts of d.o.i. Lower the latitude, the more consistent the amounts of d.o.i.

Greenhouse Effect Sun

Earth’s Atmospheric Gases Nitrogen (N 2 ) Oxygen (O 2 ) Water (H 2 O) Carbon Dioxide (CO 2 ) Methane (CH 4 ) Non- Greenhouse Gases 99% Greenhouse Gases 1%

Climate Climate: The atmospheric conditions observed over a long period of time for a large geographic region. Higher Latitude (90 ̊ N/S), cooler and drier Lower Latitude (Tropics), warmer and moist

Factors That Affect Climate Latitude Altitude: High altitude locations have a cool climate due to adiabatic (rises, cools, expands) cooling of air as it rises. Mountain Ranges: Windward and Leeward

Factors that Affect Climate Oceans/ Large Bodies of Water: Coastal locations tend to have less temperature change than inland locations Reasons for this: 1.Water holds heat down longer 2.Water has a higher specific heat, which means it needs more energy to warm up 3.Energy that hits the water causes evaporation more than heating

Factors That Affect Climate Ocean Currents Wind Belts Monsoons: Massive rainy season due to an extreme change in moisture and pressure between summer and winter (India) Typical Storm Tracks

Land v. Water Absorption The difference between the amount of radiation could be for one or more of the four following reasons: 1.Water has a higher specific heat than landhigher specific 2.Water reflects lower angle insolation better than land 3.Water is transparent so insolation goes down further into it 4.Convection currents bring insolation further into the hydrosphere

Reflection of Insolation The Poles are colder than the Equator, even though they both get 12 months of sun and 12 months of darkness, because: 1.Snow at the Poles reflect most of the insolation 2.The Sun is lower in the sky at the Poles (a.o.i) 3.Sunlight must travel a greater distance through the atmosphere b/c the Sun is so low in the sky, so it loses energy.

The Insolation-Temperature Lag The Insolation-Temperature Lag is the time delay between the maximum and minimum insolation and the maximum and minimum air temperature. Ex. Temp at 6AM compared to Temp at 2PM Ex. Temp of the ocean in June compare to Temp of the ocean in October.

History of Earth’s Climate Earth formed ~4.6 billion years ago Originally very hot Sun’s energy output only 70% of present Liquid water present ~4.3 billion years

History of Earth’s Climate Life appeared ~3.8 billion years ago Photosynthesis began billion years ago – Produced oxygen and removed carbon dioxide and methane (greenhouse gases) – Earth went through periods of cooling (“Snowball Earth”) and warming Earth began cycles of glacial and interglacial periods ~3 million years ago