Weather Unit13.1 - A Closer Look at the Earth

13.2 – Earth’s Energy Balance

13.3 – Seasons & the Angle of Sunlight

http://youtube.com/watch?v=s76Qn7bpCsQ&feature=related

Weather and Climate Weather… What is It?

– Day to day environmental conditions Examples:

– Rainy / snowy– cloudy / sunny– Windy / calm

Climate– Environmental condition averaged over

many years Examples:

– Average rainfall– Average daily temperature

Variables used to describe weather and climate:– Temperature– Wind Speed and Direction– Visibility– Cloud cover– Atmospheric Pressure– Dew Point– Humidity

Formation of Weather and Climate

1. Is the weather is the same here as it is in Saint John? Why or not?

2. Geographically, how is Saint John different than Fredericton?

3. Would any of these geographical features affect the weather in that area? If so which ones and how?

Here are the facts:Components that influence weather and climate

include: Latitude and Longitude Atmosphere Oceans Land Masses

Influences on Weather and Climate and Latitude/Longitude

Components that influence weather and climate include:

Latitude and Longitude

Atmosphere (later)

Oceans (later) Land Masses

(later)

Latitude & Longitude

Longitude (Meridians)

Angle of measure east or west of the Prime Meridian

Imaginary vertical lines

Label on Your Map Prime Meridian 0o

(Greenwich, England) International Dateline

180o

Latitude (Parallels)

Angle of measure north or south of the Equator Imaginary horizontal lines

Label on Your Map:(BLM 13.1A)

Equator 0o

North Pole 90oN South Pole 90oS Arctic Circle 67.5oN Antarctic Circle 67.5oS Tropic of Cancer 23.5oN Tropic of Capricorn 23.5oS

Mapping Activity Short Worksheet –

– Part A: students to determine latitude and longitude of a location

– Part B: students to determine location based on latitude and longitude.

13.2 – Energy SystemsEnergy (heat or light) is transferred in

one of the following ways:

Radiation Convection Advection Conduction

Radiation Where does it come from?

– produced by nuclear fusion reactions in the sun How does Solar Energy reach Earth?

– Radiant energy travels in waves of different energy levels, collectively known as the Electromagnetic Spectrum

– In order from lowest to highest frequency: Radio Microwave Infrared Visible Ultraviolet X-rays Gamma

Advection Transfer of energy through the collision

of particles in a liquid or gas Energy moves horizontally

Conduction the transfer of energy

which occurs when a particle with high energy hits a particle with lower energy

thus energy is passed through an object from atom to atom

only occurs in solids, since the particles must be close together for frequent collisions to occur readily

Heat Capacity a measure of how much heat a substance

must absorb to increase its temperature by 1 o C

if a substance absorbs a lot of heat, yet its temperature rises slowly, then it has a high heat capacity (e.g. water)

if a substance absorbs a lot of heat, and its temperature rises rapidly, then it has a liow heat capacity (e.g. metals)

See Figure 5 p.506.

Heat Sinks an object which absorbs large amounts

of energy

substances with high heat capacities make a good heat sink

e.g water, concrete

Absorption and Reflection solar energy entering the atmosphere can

be either absorbed or reflected

approximately 70% in total is absorbed – 44% heat the Earth’s land surface and air– 25% heat the water and evaporate some water– 1% creates wind– Less than 1% is used for photosynthesis

approximately 30 % is reflected(air 6%, clouds 20%, earth 4%)

Why is Solar Energy Important? all forms of life on earth are dependent on

solar energy for life needed for plants to grow and to keep earth

warm enough for survival– Reminder: less than 1% is used by Photosynthesis.

• PHOTOSYNTHESIS – The process by which green plants use sunlight to produce sugar.

CO2 + 2H2O + sunlight ---> O2 + C6H12O6 + H2Oor...

carbon dioxide + water + sunlight ---> oxygen + carbohydrate + water

13.3 – Seasons and the Angle of Sunlight

Video: Bill Nye (Seasons) Handout: Seasons Worksheet (24 min)

13.3 - Reason for the Seasons

• The average tilt, 23.5o, of the Earth is the reason for the seasons)

• As the Earth revolves around the Sun, the seasons in the northern and southern hemispheres are opposite.

http://geovideos.fliggo.com/video/NY5Lxu6q

Earth’s Rotation and Revolution Rotation (24 hours)

– The Earth rotates on its axis– The axis (imaginary line) runs North to

South 23.5o angle

– One Earth rotation takes one day Rotate East to West

Revolution (365 Days)– The Earth revolves around the Sun

The movement of one object traveling around another

– It takes the earth one year to revolve (travel) around the Sun counter clockwise

Any ideas as to how earth’s tilt towards or away from the sun can effect the 4

season’s we experience here in Canada??

I. Tilt of the Earth’s axis towards or away from the sun creates the seasons

Earth’s Seasons

North Pole

Earth

When the north pole tilts toward thesun, it gets more radiation – more warmth

during the summer

SUMMER (Northern Hemisphere)

South Pole

WINTER (Southern Hemisphere)

When the north pole tilts toward thesun, the south pole tilts away

So when it’s summer in the north, it’s winter in the south

Equator

I. Tilt of the Earth’s axis towards or away from the sun creates the seasons

Earth’s Seasons

When the north pole tilts away from the sun, it gets less radiation –

So it’s colder during the winter

North Pole

Earth

WINTER (Northern Hemisphere)

South Pole

SUMMER (Southern Hemisphere)

When the north pole tilts away from thesun, the south pole tilts toward it…

When it’s winter in the north, it’s summer in the south

Equator