Lecture 4 Radiation, Earth-Sun Relations

Question 1

At ______, which is Earth’s closest position to the Sun, occurring on January 3 during the Northern Hemisphere winter

Answer 1

perihelion

1.47×10^8
km

Question 2

At ______, which is Earth’s farthest position from the Sun, occurring on July 4 during the Northern Hemisphere summer

Answer 2

Aphelion

1.52×10^8
km

Question 3

The ______ is the periodic variation in the Sun’s activity and appearance over time.

Answer 3

Solar cycle

Question 4

______ are surface disturbances caused by magnetic storms.

Answer 4

Sunspots

Question 5

Clouds of electrically charged particles emitted by the Sun’s corona and surging towards the
Earth are called?

Answer 5

Solar wind

Question 6

The ______ deflects the solar wind toward both of Earth’s poles so that only a small portion of it enters the upper atmosphere.

Answer 6

magnetosphere

Question 7

______ that are aimed toward Earth often cause spectacular auroras

Answer 7

Coronal mass ejections

Question 8

True or False: Short wavelengths have high frequency.

Answer 8

True, long, have low frequency

Question 9

The Sun emits radiant energy composed of ______% ultraviolet, X-ray, and gamma-ray wavelengths; ______% visible light wavelengths; and ______% infrared wavelengths

Answer 9

8, 47, 45

Question 10

True or False: the hotter the object, the shorter the mean wavelength of maximum intensity emitted

Answer 10

True

Question 11

True or False: The sun inputs short radiation and the earth outputs long radiation.

Answer 11

True

Question 12

______ is the region at the top of the atmosphere

Answer 12

Thermopause

Question 13

______ is radiation arriving at Earth’s atmosphere and surface

Answer 13

Insolation

Question 14

The Sun has a ‘surface’ temperature of approximately

_____K, while the Earth has a temperature of approximately ______ K

Answer 14

6000, 300

Question 15

______ is the only point receiving perpendicular insolation at a given moment—that is, the Sun is directly overhead.

Answer 15

Subsolar point

Question 16

Why is the equator the hottest?

Answer 16

Sun’s rays arrive parallel to each other at Earth’s surface

Question 17

A ______ is a perfect absorber of radiant energy; it absorbs and subsequently emits all the radiant energy that it receives

Answer 17

blackbody, ie sun

Question 18

What is the equation for net radiation?

Answer 18

Q* = Incoming - Outgoing

Q* = (K9 + L 9) - (K8 + L8)

K down (K down): Incoming Shortwave
K up(K up): Outgoing Shortwave
L up(L up): Outgoing Longwave
L down (L down): Incoming Longwave

Question 19

True or False: Kdown values are greatest in the equatorial regions and lowest in the polar regions with
much more variation in the polar regions.

Answer 19

True

Question 20

What are the 5 reasons for the seasons?

Answer 20

Revolution
Orbit around the Sun; requires 365.24 days to complete at 107 280 km·h−1

Rotation
Earth turning on its axis; takes approximately 24 hours to complete

Tilt
Alignment of axis at about 23.5° angle from perpendicular to the plane of the ecliptic (the plane of Earth’s orbit)

Axial parallelism
Unchanging (fixed) axial alignment, with Polaris directly overhead at the North Pole throughout the year

Sphericity
Oblate spheroidal shape lit by Sun’s parallel rays; the geoid

Question 21

______determines daylength creates the apparent deflection of winds and ocean currents and produces the twice-daily rise and fall of the ocean tides in relation to the gravitational pull of the Sun and the Moon.

Answer 21

Rotation

Question 22

True or False: The speed of rotation is fastest at the poles.

Answer 22

False, slowest at poles, fastest at equator

Question 23

The dividing line between day and night is the ______

Answer 23

Circle of illumination

Question 24

Earth’s axis is tilted about ______.

Answer 24

23.5 degrees

Question 25

______ is a plane (flat surface) intersecting all the points of Earth’s orbit.

Answer 25

plane of ecliptic

Question 26

______ is Earth’s axis remains aligned the same throughout the year

Answer 26

Axial parallelism

Question 27

True or False: net radiation is most negative in the equatorial regions

Answer 27

False, polar regions

Question 28

The times around December 21 and June 21 are solstices. Strictly speaking, the solstices are specific points in time at which the Sun’s declination is at its position farthest north at the ______, or south at the ________

Answer 28

Tropic of cancer, Tropic of capricorn

Question 29

During the ______, the circle of illumination excludes the North Pole region from sunlight but includes the South Pole region. The subsolar point is about 23.5° S latitude, the Tropic of Capricorn parallel.

Answer 29

December solstice

Question 30

______ is when the Earth experiences 12- hour day and q2 hour night.

Answer 30

equinox

Question 31

______ is a measure of the ability or capacity of a system to do work

Answer 31

energy

Question 32

True or False: Energy cannot be created or destroyed, but the form of energy can change. Energy can be transferred from one location to another

Answer 32

True

Question 33

Heat absorbed or released as the result of a phase change is called ______.

Answer 33

Latent

Question 34

______ is the energy a object posses due to motion

Answer 34

kinetic

Question 35

______ is energy within object or system due to movement of particles within object or system

Answer 35

Thermal

Question 36

______ energy stored in object due to its position relative

Answer 36

Potential