Seasons
Earth revolves around the sun
Once a year every 365.25 days.
What is the degree of Earth's tilt?
23.5 degrees
How many hours does it take earth to make one full rotation?
24 hours
Which angles have lower levels of energy?
45 and 15 degree angles
Which angle has the greatest amount of energy to the floor?
90 degree angle
At what time of day is the sunlight the strongest?
At noon, when the sun reaches its highest point
Areas of the plant where solar radiation shines directly down on earth are subjected to more intense energy than areas that experience beam spreading.
The greater amount of energy absorbed, the hotter an area becomes. This is why the hottest part of earth is in the region of the tropics. This is also why mornings and evening are cool, and the hottest part of the day is in the middle.
Seasons are caused by
The tilt of the Earth's axis and where earth is in its orbit around the sun.
When the Northern Hemisphere experiences summer, the Southern Hemisphere experiences:
Winter (Northern and southern hemispheres experience the seasons in the same order but at different times)
when is the energy least intense in the extreme north and south regions of the planet?
in the morning and the evening
Light coming at an angle is
less intense
When few rays hit an area, energy density is
low
Light shining directly above is
most intense
Almost all of the energy coming to the planet earth is
solar energy.
At what time of the year does the noon sun rise highest in the sky?
summer
What time of the year would you visit beaches of Argentina? Hint: it is located in southern hemisphere (south of the equator)
summer (Dec-February)
direct sunlight
sunlight that hits the plate at a 90 degree angle
Indirect Sunlight
sunlight that hits the plate at an angle less than 90 degree angle
Why is it warmer in the summer than in the winter?
the Sun is higher in the sky and the days are longer.
Solar angle
the angle at which light strikes a surface
The reasons for seasons have a lot to do with
the angle at which the sun's rays hit earth.
The greater the solar angle,
the greater the density of radiant energy
Winter Solstice
December 21, shortest day of the year, we are tilted away from the sun, it is colder because we receive indirect sunlight
Because earth's axis is tilted, the norther hemisphere receives more intense solar energy in the summer months, making summer hotter.
During the winter months, sunlight strikes the norther hemisphere at a lower solar angle, resulting in less heating from solar radiation.
Summer Solstice
June 21, longest day of the year, temperatures rise and the amount of sunlight increases, the Northern Hemisphere is pointed toward the sun, it is warmer because we receive direct sunlight
Spring Equinox
March 21, equal amounts of light and darkness
Solar energy is most intense during what part of the day in the region of the tropics?
Middle
What influence does solar angle have on heating the earth?
Places on earth receiving more intense energy or higher power will be warmer. for example tropics are warmer and places closer to the equator. This is also why it gets hotter in the middle of the day and and in the afternoon. Places on the earth receiving less intense energy or lower power will be colder. for example the north pole and south pole. This is also why it is colder in the morning time and evening time.
Energy travels from the sun to the earth as radiation.
Radiant energy travels in rays.
Fall Equinox
September 21, equal amounts of light and darkness
the amount of light does not change.
all that changes is the angle at which the light strikes the surface
What do you notice about earth's axis as earth revolves around the sun?
always stays tilted at 23.5 degrees and points towards north star (Polaris)
When lots of rays hit an area, energy density is
high
How does orientation of earth's axis relate to the position of the sun in the sky?
in northern hemisphere when earths' axis is closer to the the sun(north star/Polaris) there is more direct sunlight and very little beam spreading
energy density
the number of rays hitting a given area
North Star (Polaris)
the star the Earth's axis points toward
beam spreading
the way a light beam covers a larger area when it hits a surface at an angle
What time of year would you plan a vacation in new Zealand? Hint: it is located in southern hemisphere (south of the equator)
winter (may-august)
What are the four seasons?
winter, spring, summer, fall