Earths Motion And Insolation

Question 0

Insolation and earths layers

Answer 0

• insolation reaches earths surface by first passing through the atmosphere
• most visible light from the sun is transmitted through the atmosphere
• however!!!! Insolation may be absorbed, reflected, or scattered before reaching earths surface

Question 1

Insolation

Answer 1

• incoming, solar, radiation
• suns output of electromagnetic radiation that earth receives
• the intensity of insolation is the relative strength of the suns radiation
• which reaches a specific area of earth in a specific amount of time
• intensity of insolation increases temperature increases

Question 2

Insolation 2

Answer 2

Intensity: the strength of insolation; rate at which solar energy is received by a given area in specific amount of time
Duration: the length of time of insolation received by a given area
Remember!!!! The duration of insolation will change based on the season/time of year and the latitude
- when insolation strikes a surface at a 90 degree angle it has it’s maximum intensity(highest heating effect)
- sphere and not flat there is only one location at a time where insolation will be at a 90 degree angle
- duration of insolation is the length of day; most in summer less in winter

Question 3

Equinox and solstice

Answer 3

Fall equinox: September 23
Spring equinox: March 21
Winter solstice: December 21
Summer solstice: June 21

• fall and spring equinoxes the intensity of insolation is at the equator
• summer solstice the intensity of insolation is at the Tropic of Cancer 23.5 degrees north
• winter solstice the intensity of insolation is at the Tropic of Capricorn 23.5 degrees south

Question 4

Why do we have seasons

Answer 4

• seasons are result of the tilt of the earths axis
• the number of daylight is greater for the hemisphere tilted toward the sun
• summer is warmer than winter (in each hemisphere) because the suns rays hit the earth at a more direct angle during summer than in winter
• the days are longer than the nights in the summer
• during the winter the suns rays hit the earth at an extreme angle and days are short: also due to the tilt of earths axis

Question 5

Solstices

Answer 5

• winter: northern hemisphere day lasts fewer than 12 hours and the Southern Hemisphere day lasts more than 12 hours
• winter solstice: North Pole has 24-hour night, South Pole has 24-hour day
• summer: northern hemisphere day lasts more than 12 hours and the Southern Hemisphere day lasts less than 12 hours
• summer solstice: North Pole has 24-hour day, South Pole has 24-hour night
• a day lasts 12 hours and a night lasts 12 hours at all latitudes
• sunlight strikes the earth most directly at the equator 2x a year

Question 6

Summer solstice

Answer 6

• Sun rises: north of east
• sun sets: north of west
• suns altitude highest of year
• ny gets 16 hours of daylight
• North Pole gets 24 hour day
• suns rays hit Tropic of Cancer 23.5 degrees

Question 7

Winter solstice

Answer 7

• sun rises: south of east
• sun sets: south of west
• suns altitude lowest if the year
• ny gets 8 hours of daylight
• North Pole gets 0 hours daylight
• suns rays hit Tropic of Capricorn 23.5 degrees

Question 8

Equinoxes

Answer 8

• sun rises due east
• sun sets due west
• suns rays hit the equator

Question 9

Long Island: altitude of noon sun 41 degrees north

Answer 9

June 21: summer solstice
December 21–26 degrees
March 21 $ September 23–49 degrees

Question 10

Earth motions

Answer 10

• earths spinning on its axis is its rotation
• axis is tilted 23.5 degrees from a line perpendicular to the plane of its orbit to the sun
• as earth orbits/revolves around the sun, earths axis remains stationary
• earth rotates 360 degrees from west to east in a 24 hour rate of 15 degrees per hour

Question 11

Evidence of earths rotation: the Foucault pendulum

Answer 11

1. The Foucault pendulum: when it is allowed to swing freely it’s path will appear to change in a predictable way: this is evidence of earths rotation because if earth did not rotate the pendulum would continue to swing in its original path instead of making a star pattern

Question 12

Evidence of earths rotation: Coriolis effect

Answer 12

• the tendency of particles of matter moving at earths surface to be deflected or curve away from a straight line path: Coriolis effect
• the deflection to the right is in the northern hemisphere
• deflection to the left is in the Southern Hemisphere
• occurs because earth is rotating

Question 13

Earth revolves around the sun

Answer 13

• earth revolves around the sun in a slightly eccentric elliptical orbit once a year, in a counter-clockwise direction at a rate of 1 degree per day

Question 14

Evidence of earths revolution around the sun: seasonal changes

Answer 14

• these changes are associated with changes in the suns path
• if earth did not revolve around the sun the seasons would never change because the same part of earth would always tilt towards the sun

Question 15

Evidence of earths revolution around the sun: different constellation

Answer 15

• Constellations: a group of stars that form a pattern and are used to help people locate celestial objects

Question 16

Evidence of earths revolution around the sun: apparent diameter of the sun

Answer 16

• the apparent diameter of the sun changes in a cyclic way
• the sun appears largest when earth is closest to the sun on January 3rd
• the sun appears furthest away from earth when earth is further from the sun on July 4th

Question 17

Motions of earth moon and sun

Answer 17

• an apparent motion is a motion that an object appears to make
  - ex. The stars appear to move across the sky from east to west—- this apparent motion is caused by earths rotation
• the paths of all celestial objects moving in the sky are circular or parts of a circle called an arc
• over time planets appear to change position in the sky–this complicated motion of the planets is the result of earth and other planets revolving around the sun in different orbits at different speeds

Question 18

Apparent motion of the sun

Answer 18

• the suns apparent path from sunrise to sunset is the shape of an arc
• the suns path changes both it’s position and it’s length with the seasons
• the greater the length of the suns path over an area the more hours of daylight that area has
  -‘the sun always reaches its highest position in the sky at local solar noon
• however the altitude of the sun at noon depends on the time of year and the latitude of the observer
• ***only between latitudes 23.5 degrees N and 23.5 degrees S can the noon sunn be directly overhead (at the altitude of 90 degrees) therefore the noon sun is NEVER directly overhead in the state of NY
• sun is most intense at the 90 degree angle your zenith but ny never gets that
• at ny at noon u have to face south to see the sun (shadow points north)
• ## the equator always receives a 12 hour daylight and a 12 hour nighttime

Question 19

Models that explain celestial motions

Answer 19

• early cultures tried to explain the daily motions of celestial objects
• some cultures assumed that earth was stationary an most of the celestial objects revolved around it
• this idea is called the geocentric model: model was accepted in European cultures up to the 16th century
• other ancient cultures use a heliocentric model or a sun-centered model to explain the apparent motions of celestial objects in earths sky
• the heliocentric model states that the sun is the center of motion
• this idea included what we go by today: earth spins/rotates on a imaginary axis, earth orbits/revolves the sun, and the moon orbits/revolves the earth

Question 20

Dun path for summer an winter

Answer 20

• the sun makes an arc in the sky from sunrise to sunset
• the sun moves 15 degrees per hour
  - ex. 3pm to 5pm the sun moved 30 degrees— two hours to get from 3 to 5 15 degrees per hour—15 + 15= 30 degree
• the highest point of the suns path is called solar noon

Question 21

Shadow length during day

Answer 21

• shadow is the shortest at the suns highest angle – solar noon
• ## shadow longest at sunrise and sunset this is also when the sun is at its lowest angle

Question 22

Shadow length during year

Answer 22

• Shadows longer during winter: suns lower angle
• shadows shorter during summer: suns higher angle
• fall and spring: the shadow is average