The Reasons for the Seasons

A post lab experience…

…because you have a Moodle Quiz this weekend….

….and science is just too darn fun!

10°30°50°70°

The angle shown here between the light and the thermometer…

simulates the curved surface of the Earth…

23.5° (tilt)

0° Equator

70° Latitude

30° Latitude

Because the surface of the Earth is curved, certain portions receive direct rays and other portions receive indirect rays

50° Latitude

Direct and In-Direct Rays

A direct ray is directly overhead… an in-direct ray is not.

SUN

70° Latitude 30° Latitude 0° Equator

SUN

This means that the energy becomes less concentrated as the ray becomes less direct.

As the angle increases, the amount of land that is receiving solar radiance also increases.

The area increases, but the amount of solar radiance is the same

because the predominant ray is ….

Winter SolsticeDecember 21

Summer SolsticeJune 21

Fall (Autumnal) EquinoxSeptember 21

Spring (Vernal) EquinoxMarch 21

SUN

In-direct on the… Direct on the…

Equal on the…

Equal on the…

In the northern hemisphere…the season is….

Winter

Fall

Summer

Spring

A Note about Graphing Data…

Time (minutes)

Tem

pera

ture

(°C

)

Title, Labels & Units

Format Axes

Data trends

Understanding Temperature and the Layers of the AtmosphereWhy does the temperature change in the different layers of the atmosphere?

Different wavelengths of the EMS are absorbed at different layerswhich cause temperature increases!

Gamma & X-rays are absorbed in the exosphere & thermosphere!

Most of the UV rays from the Sun are absorbed by the ozone layer (which is in the stratosphere)!

All visible light passes through the entire atmosphere and is absorbed by the surface of the Earth!

Summarizing thoughts…

• When Nuclear Fusion occurs in the Sun, energy is released.

• The energy is described in the EMS.

• The only portion that reaches the surface of the Earth (with any effect) is the visible light (radiant) portion of the EMS.

Notes from Video

• What is the earliest known use of wind power?• What were the first windmills used for?• What is a “wind farm”?• Why are wind turbines positioned so high above the ground?• What are some of the components found inside a wind

turbine?• A wind turbine converts _____________ energy into

____________ energy.• What causes wind?• What is the original source of the energy carried by the wind?