EOSC 112 Midterm 1

define the atmosphere

thin layer of gas enveloping the earth

define the hydrosphere

all the water found on Earth in liquid, solid, or gas form

define the geosphere

all the solid materials that make up earth's crust and interior

define the biosphere

encompasses all living things

what is the main driver of energy on earth

the sun

the earth system is driven by the continuous input of ________ _______

solar energy

what determines the mean temp and habitability of the planet

flux of solar energy (solar constant)

what drives atmospheric and oceanic circulation and why do they affect climate

solar energy

they redistribute heat energy from equator to poles and dictate precipitation patterns

what does the model of the Earth System look like

solar energy as main driver

atmosphere, hydrosphere, and solid earth on outside

biota centred

what are the 3 main factors controlling Earth's climate

1. amount of solar radiation received by Earth

2. amount of solar radiation absorbed by Earth

3. redistribution of solar radiation on Earth's surface

what 2 things control the amount of solar radiation received by Earth

1. intensity of solar radiation

2. Earth's orbit

what 2 things control the amount of solar radiation absorbed by Earth

1. Earth's albedo

2. greenhouse gases

what 2 things control the redistribution of solar radiation on Earth's surface

1. atmospheric circulation

2. ocean circulation

what 2 things does temperature depend on

1. intensity of solar radiation

2. distance from sun

(both vary through time)

albedo

how much radiation in absorbed (rest is reflected)

aka the reflectivity of a surface

high albedo = _____ reflectivity

high (not as much solar radiation absorbed)

the sun transfers energy to Earth in what form

electromagnetic radiations

define solar constant

the amount of solar radiation (energy) reaching Earth per unit time (seconds) and per unit surface area (metres squared)

why is the solar constant relevant

one of the main factors determining the mean temperature of earth, and habitability

photovoltaics

solar panels

what could provide an inexhaustible source of energy

solar energy

which type of energy is fundamentally not solar (and the only one not solar)

geothermal

how can you find the temp of the sun

from the characteristics of the radiation it emits (electromagnetic radiations)

T or F - any material whose temp is above absolute zero emits electromagnetic radiations

True

T or F the speed of a wave does not change

True

waves propagate at a fixed speed (c)

frequency (v)

number of crests that pass a fixed point per second

speed of wave (c) = ______ x ______

wavelength (lambda)

frequency (v)

short wavelength = _____ frequency

high

long wavelength = ______ frequency

low

the electromagnetic spectrum moves from ____ wavelength to ____ wavelength

short

long

according to Wien's law, the hotter the object, the ________ the wavelength

shorter

absolute zero

temp at which atoms are not vibrating (use Kelvin for absolute temp) - lowest temp on K scale

what 2 things happen as heat is applied

1. atoms vibrate faster

2. temp increases

K = C + _____

273

absolute zero is 0 K, which is ____ C

-273

as temp increases, radiation emitted ______

increases (atoms are vibrating faster)

T or F - at absolute zero, there is no radiation emitted

True

atoms are not moving, no radiation

T or F - any body with a temp above absolute zero emits electromagnetic radiation

True

Stefan-Boltzmann's law relates Temp to what?

amount of energy emitted per unit time and area

F = oT^4

surface area of a sphere is ____ times the surface area of a circle

4

surface area of a sphere

4pir^2

what happens to energy as it moves away from the sun

energy is spread over a bigger and bigger area

the amount of energy that reaches the Earth from the sun depends on what

distance between the Earth and the sun

the farther away from the sun, the ______ the solar constant

smaller

solar constant

amount of solar energy per second per square metre

T or F - the solar constant is truly constant

False

what 2 things does the solar constant depend on

1. energy output by the sun

2. earth-sun distance

why does Earth receive less radiation than the solar constant?

it is a spinning sphere (must consider surface area and divide by 4)

roughly how much solar radiation is reflected back to space and why

30%

due to Earth's albedo (reflectivity)

what 2 components make up earth's albedo

1. clouds (26% of reflecting)

2. Earth's surface (4%)

T or F albedo varies for different surfaces on earth

True

which has a higher albedo - ice caps and deserts or forests and oceans

ice caps and deserts

earth's radiation balance

Fabs=Fem

in order to keep the temperature constant, earth must emit the same amount of electromagnetic radiation that it absorbs

what is earth's effective radiating temperature

-18 degrees C

the temperature the corresponds to the radiation absorbed and emitted by earth (radiation balance) according to the Stefan Boltzmann's equation

what are 7 main steps in finding the effective radiating temperature of Earth

1. apply Wien's law to radiation emitted from sun

2. apply Stefan Boltzmann's equation to find energy emitted from sun

3. factor in geometry of a sphere

4. calculate solar constant

5. factor in Earth's shape and rotation to find total energy reaching planet

6. consider albedo

7. consider radiation balance

on earth the mean surface temp is ________ than the effective radiating temp due to what

warmer

greenhouse warming

Earth only emits ________ radiation

infrared

what 3 wavelengths of radiation does the sun emit

1. visible light

2. UV

3. infrared

greenhouse warming arises from what concept in Earth's atmosphere

Earth's atmosphere is not equally transparent to all wavelengths of electromagnetic radiations (infrared radiation trapped inside)

the earth's atmosphere is transparent to _______ and some _______ radiation from the sun

visible light

infrared

the earth's atmosphere absorbs _______ radiation from sun

UV (due to ozone layer)

most energy from the sun _____ the atmosphere, while most energy from earth is ________ the atmosphere

passes through

absorbed

greenhouse warming is produced by what

atmospheric trapping of infrared radiation emitted by earth's surface

T or F - nitrogen and oxygen do most of the absorbing of infrared radiation in the atmosphere

false!

they do not have the capability to absorb infrared

ozone does most of the absorbing

what are the 3 most important greenhouse gases and what do they do

1. water vapour

2. carbon dioxide

3. methane

absorb outgoing infrared radiation from earth

what would the earth's temp be if there were no greenhouse gases

equal to the effective radiating temp

everything in = everything out

why is the mean temp of earth lower than the simplified model estimate (3 reasons)

1. greenhouse gases let some radiation escape

2. there is an ozone layer to absorb incoming UV

3. latent and sensible heat were not considered in simple model

sensible heat

the heat that we feel to the tough and which is directly linked to temperature

how is sensible heat transferred from the surface to the atmosphere

surface heats atmosphere above

air warms and expands

density decreases and air rises

convection currents transfer this warm air higher up

if you increase temp, a gas will ______

expand

latent heat

not linked to temperature and we cannot feel it (hidden heat)

heat released back into environment when water condensates and freezes

how is latent heat transferred to the atmosphere

solar heat warms surface water and forms water vapour which is released in the atmosphere

what happens to the density of air as temp is increased and why

decreases (air rises)

more evaporation means more water vapour which replaces heavier molecules making air lighter

T or F - both sensible and latent heat contribute to decreasing air density in the lower atmosphere which then moves downwards

False!

air moves upwards (lower density --> hot air rises)

cloud formation ______ heat taken up from Earth's surface high up in the atmosphere

releases

latent and sensible heat help keep the surface ______ than it would otherwise be

cooler

T or F - the radiation budget is constant and is not bothered by changes in other parts of the system

false

in a state of equilibrium but susceptible to change if there are changes in other aspects (solar constant, albedo, and greenhouse gases)

what 3 elements of the radiation budget may change and disrupt the equilibrium

1. solar constant

2. albedo

3. greenhouse gases

the farther the planet is away from the sun, the ________ the solar constant

smaller

how much energy does the top of an atmosphere of a spinning planet receive if the solar constant is 4000?

1000

divide solar constant by 4 for spinning spherical planet

what happens to:

1) the solar constant

2) solar energy intercepted

3) amount of solar energy received per square metre

if a planet were to double in radius

1) stays the same (distance in orbit not changing)

2) would intercept 4x more solar energy (SA is now 4x previous amount)

3) stays the same

how do you find the amount of solar energy intercepted by a planet

solar constant x surface area of circle (pi r^2)

how do you find the average amount of solar radiation per square metre for a planet

amount of solar radiation intercepted / surface area of sphere (4pi r^2) (solar constant/4)

why is there more direct sunlight at the equator

suns angle decreases with latitude due to earth's curvature (more solar radiation concentrated over a smaller area at the equator)

is the amount of solar energy absorbed at the surface equal everywhere? why or why not

no

more intense at equator where there is direct sunlight, less at poles where there is less radiation reaching (due to earth's curvature)

albedo varies with surface

compared to amount of solar radiation absorbed, infrared radiation emitted varies _____

less

what is the warming effect at the equator

absorbs more energy than it emits (cooling effect and opposite at poles)

at low lats there is net _______

at high lats there is net ______

heating

cooling

what does the differential heating at earth's surface generate

atmospheric and oceanic circulations (redistribute heat from the equator to the poles)

why are there numerous convection cells on Earth

due to rotation (number of cells depends on speed of rotation)

from the equator to the poles what are the 3 cells

1. hadley

2. ferrel

3. polar

what is the air process at hadley cells

warm wet air rises and descends around 30 degrees N or S

what is the air process at polar cells

cold dry air descends at poles, hits ground and flows to the equator

what is the air process at ferrel cells

air from hadley cell either diverges to the poles or the equator, diverges to poles, warm air meets cold air and rises up over it

air sinking

__________ air density

__________ pressure at ground level

higher

higher

air rising

_______ air density

_______ pressure at ground level

lower

lower

dry conditions relate to what type of air

cooler, dry, sinking air

wet conditions relate to what type of air

warmer, wet, rising air

ITCZ is where winds _______ and _______

converge

rise

cloud formation is associated with ______ and an _______ temperature of surrounding air mass

condensation

increased