Basics Of Climate Change

Question 1

What is climate?

Answer 1

The statistical properties of meteorological conditions over a given period

Question 2

What is the given period for studying climate?

Answer 2

30 years

Question 3

What is the atmosphere?

Answer 3

A relatively thin layer of gases that is held around the Earth by gravity

Question 4

Where is the troposphere?

Answer 4

Between the surface and 8-15km

Question 5

Where is the troposphere deepest and shallowest

Answer 5

Deepest at the tropics, shallowest at poles

Question 6

Does temp increase or decrease with altitude in the troposphere?

Answer 6

Temp decreases with altitude

Question 7

What is the lapse rate?

Answer 7

Lapse rate is the gradient of temperature in the atmosphere

Question 8

Where is the tropopause?

Answer 8

Top of the troposphere

Question 9

Where is the stratosphere?

Answer 9

From top of tropopause to 50km

Question 10

Does temp increase or decrease with altitude in the stratosphere?

Answer 10

Temp increases with altitude

Question 11

Where is the ozone layer located?

Answer 11

In the stratosphere

Question 12

Where is the mesosphere located?

Answer 12

From the stratosphere to 80-100km

Question 13

Does temp increase or decrease with altitude in the mesosphere?

Answer 13

Temp decreases

Question 14

Where is the thermosphere?

Answer 14

From the mesosphere up to 600km

Question 15

What is the exosphere?

Answer 15

The uppermost layer of the atmosphere

Question 16

What is the relationship between sunlight received and latitude?

Answer 16

Sunlight received (Wm^-2) is proportional to cos(latitude)

Question 17

Where is the most and least sunlight received?

Answer 17

Max at equator, minima at poles

Question 18

Is incoming sunlight long or shortwave?

Answer 18

Shortwave

Question 19

Is outgoing terrestrial radiation long or shortwave?

Answer 19

Longwave

Question 20

What is a cell e.g. Hadley cell, polar cell

Answer 20

Direct circulations caused by heating and ascent in atmosphere/surface

Question 21

Where is the Hadley cell? What direction are the solar winds?

Answer 21

At the equator between 0 and 30 degrees, direction away from equator

Question 22

Where is the polar cell, what direction are the solar winds?

Answer 22

At the poles, between 60 and 90 degrees, direction away from equator

Question 23

Where is the Ferrel cell, what direction are the solar winds?

Answer 23

Between Hadley and polar cell between 30 and 60 degrees, direction towards equator

Question 24

What is the relationship between sunlight absorbed and outgoing terrestrial radiation?

Answer 24

Sunlight absorbed=outgoing terrestrial radiation

Question 25

What does Coriolis force do?

Answer 25

Leads to the deflection of flows to the right in northern hemisphere and to the left in Southern Hemisphere

Question 26

What is the net function of atmosphere and ocean?

Answer 26

To distribute the heat from the equator pole wards

Question 27

What are the characteristics of cirrus clouds?

Answer 27

Cold, thin, high up, made of ice

Question 28

Why do high clouds trap more energy than low clouds?

Answer 28

Not much solar radiation reflected back to space, lots of terrestrial radiation absorbed

Question 29

Do high clouds warm or cool environment

Answer 29

Warm

Question 30

Why do low clouds trap less energy that high clouds

Answer 30

They reflect more solar radiation to space, and smaller LW radiative forcing

Question 31

Do low clouds warm or cool the environment?

Answer 31

Cool

Question 32

What is cloud radiative forcing?

Answer 32

The difference between radiation emitted to space for average atmospheric conditions, and then also without clouds for same region and time period

Question 33

Describe why SW CRF is negative

Answer 33

More clouds in the sky create a higher albedo, and more SW is reflected back to space. Therefore SWCRF fullsky > SWCRF clear, so SWCRF is -ve

Question 34

What is the equation for SW CRF

Answer 34

SW CRF = SWclearCRF - SWfullskyCRF

Question 35

Describe why LW CRF is positive

Answer 35

More clouds in the sky mean more LW radiation trapped at the surface, so less LW radiation is emitted to space. LWclear CRF > LWfullsky CRF, Therefore LW CRF =+ve

Question 36

What is the equation for LW CRF?

Answer 36

LW CRF= LWclear CRF - LWfullskyCRF

Question 37

What is the equation for net CRF

Answer 37

Net CRF = SW CRF - LW CRF

Question 38

What is the atmospheric pressure equation?

Answer 38

m_at g /A

Question 39

90% of atmospheric mass is less than what altitude?

Answer 39

Less than 10km

Question 40

What is atmospheric pressure measured in?

Answer 40

Pascals

Question 41

What is the ideal gas law?

Answer 41

P = ρR T ρ= density R= specific gas constant p=pressure

Question 42

What is the first law of thermodynamics?

Answer 42

du = dq + dw u = internal energy q = heat energy w = work

Question 43

How is the first law of thermodynamics written for atmospheric sciences?

Answer 43

dq = c_pdT -alpha dp c_p = specific heat at constant pressure Alpha =1/density p =pressure

Question 44

What is radiative forcing?

Answer 44

The change in the net energy balance at the tropopause from pre-industrial to present day caused by a perturbation to atmospheric conditions

Question 45

What are the units for radiative forcing?

Answer 45

Wm^-2

Question 46

What things may radiative forcing impact?

Answer 46

Incoming solar radiation reflected solar radiation outgoing longwave radiation

Question 47

What effect does positive radiative forcing have?

Answer 47

More energy going in than going out, so earths overall temp will increase

Question 48

Why effect does negative radiative forcing have?

Answer 48

More energy going out than in so earths overall temp will decrease

Question 49

What does GCM stand for?

Answer 49

General circulation model

Question 50

What is a GCM (not what the letters mean)

Answer 50

A type of climate model built up from discretised Navier Stokes equations

Question 51

What is the relationship between global mean temp change and radiative forcing?

Answer 51

They’re proportional dT_surf =λ RF λ= climate sensitivity parameter (K/W m^-2 )

Question 52

What do GCMs do?

Answer 52

Allow for assessment of the evolution of global mean temperatures (and more)

Question 53

What is lambda? (GCM context)

Answer 53

-Climate sensitivity parameter -normally determined from equilibrium GCM simulations -approx independent of forcing mechanism -differs among climate models :(

Question 54

What is the directional relationship between magnetic and electric fields?

Answer 54

They’re perpendicular

Question 55

What is the relationship between wavenumber an wavelength?

Answer 55

Wavelength (lambda) = 1/wave number (nu)

Question 56

Which has the higher wavelength, red or blue light?

Answer 56

Red

Question 57

What temp and wavelengths is black body radiation emitted from the sun?

Answer 57

6000K UV, visible, near IR

Question 58

What temp and wavelengths is black body radiation emitted from the Earth

Answer 58

300 K Near and far IR

Question 59

What is the equation for isotropic emission?

Answer 59

M(T) =pi B(T)

Question 60

What are some assumptions about the ‘Ball-Bearing Earth?’

Answer 60

1) no atmosphere 2) S_o invariant between equator and poles 3) alpha =reflected solar radiation/S_{o =planetary albedo}

Question 61

What are some assumptions about the Stefan-Boltzmann law?

Answer 61

1) no atmosphere 2) black body (emissivity =1) 3) surface area of Earth = 4 pi R²

Question 62

What is the relationship between solar radiation and terrestrial radiation at steady state?

Answer 62

Solar radiation absorbed =terrestrial radiation emitted S_o(1-α) πR² = 4π R²σ T⁴

Question 63

What does the atmosphere consist of?

Answer 63

78% N₂ 21% O₂ 1% other gases

Question 64

What is Rayleigh scattering?

Answer 64

Scattering of radiation caused by interaction of radiation with molecules

Question 65

What are the most significant absorbing components in the atmosphere?

Answer 65

O2 and O3 CO2 H2O

Question 66

How does the atmospheric absorption vary between solar and terrestrial wavelengths?

Answer 66

0.3-3.0 microns: mostly non-absorbing 3.0-100 microns: mostly absorbing

Question 67

How can the ‘ball-bearing’ earth model be improved?

Answer 67

Add an atmosphere layer characterised by emissivity =absorptivity

Question 68

What is an atmospheric aerosol?

Answer 68

Consists of suspension of fine solid/liquid particles suspended in the troposphere or stratosphere

Question 69

Name some effects of aerosols on clouds

Answer 69

Increase cloud albedo Increase cloud height Increase cloud lifespan Drizzle suppression

Question 70

Name the orders of the atmosphere

Answer 70

Troposphere -> stratosphere -> mesosphere -> thermosphere -> exosphere