trying to get unit 3 in my brain

Question 1

longwave radiation

Answer 1

this is emitted by the surface and passes into the atmosphere and eventually into space
there is also a downward directed stream of longwave radiation from particles in the atmosphere
the difference between the 2 streams is known as the net radiation balance
during the day, since the outgoing stream is greater than the incoming one there is a net loss of energy from the surface

Question 2

mist and fog

Answer 2

a cloud is a collection of water droplets
mist occurs when visibility is between 1000m and 5000m
fog occurs when visibility is below 1000m
fog is thicker cloud cover than mist
these clouds form at ground level because air can only hold a certain amount of moisture
colder air can hold less moisture than warmer air
once this maximum amount of moisture is reached, air is saturated and the water vapour in the air turns to liquid
this is when clouds form as condensation of water vapour to water droplets occur

Question 3

temperature inversions

Answer 3

normally air temperature decreases with altitude
there are situations where a temperature inversion occurs
this means that there is an abnormal layer of warmer air above the colder air in the tropopause
this often happens at night in calm conditions so it sometimes is known as a nocturnal inversion

Question 4

why do temperature inversions occur

Answer 4

during the day the ground is heated by the shuns shortwave radiation and after a short time it heats the air above it when it emits longwave radiation
at night the gorund surface and the air lose the heat energy that have absorbed during the day
however the ground loses heat energy faster than the air as it is a more efficient conductor of heat
by the end of the night the ground surface is therefore bery cold and the air directly above it will be cooled due to close proximity to the surface
the air layer above this will still be warmer as it has cooled lower than the ground surface causing a temperature inversoin

Question 5

impacts of temperature inversions

Answer 5

will act as a lid on pollutants causing them to remain in the lower atmosphere next to the earths surface

Question 6

sea breeze

Answer 6

on a warm summer day along the coast, this differential heating of land and sea leads to the development of local winds called sea breezes
the land is heated quicker than the sea and so the air above the land is warmer than the air above the sea during the day
as air above the land surface is heated by radiation from the sun, it expands and begins to rise being lighter than the surrounding air
to replace the rising air, cooler air is drawn in from above the surface of the sea
this is the sea breeze and can offer a pleasant cooling influence on hot summer afternoons

Question 7

land breeze

Answer 7

occurs at night when the land cools faster than the sea at night
this creates a situation which is the opposite to daytime where the air above the sea is actually warmer at night than the air above the land
in this case it is air above the warmer surface water that is heated and rises pulling in air from the cooler land surface

Question 8

rossby waves

Answer 8

large-scale fast rivers of air formed by westerly winds which follow a ridge and trough like pattern
they are affected by major topographic barriers such as the rockies and andes as they are through to form when the air has to loop around and above these blocking features
the shape of rossby waves varies over a 6 week cycle from a low zonal index to a high zonal index
in troughs there are low pressure
in ridges there are high pressure systems

Question 9

jet streams

Answer 9

are strong and regular winds which blow in the upper atmosphere about 10km above the surface as a part of the rossby wave
they blow at around 100-300kmph
there are 2 streams in each hemisphere
one between 30-50 degrees called the polar jet
ine between 20-20 degress called the subtropical jet
caused by differences in air between equatorial and subtropical air and subtropical and polar air
the greater the temperautre difference, the stronger the jet stream

Question 10

adiabatic process

Answer 10

means the rising and sinking of air
as air rises it cools and can hold less water
as air sinks it warms and can hold more water
as it rises and cools the water vapour in the air condenses back into water droplets
when a parcel of air holds the maximum amount of moisture it is saturated
the point at which a parcel of air is saturated is the dew point
the altitude at which dew point is reached is the condensation level

Question 11

lapse rates

Answer 11

the rate of temperature decreases with altitude
it vaires according to height, time of year and over different surface
when parcel sof air move up through the atmosphere they cool at a different rate to the surrounding air
this means they have a different lapse rate
this is the adiabatic lapse rate

Question 12

dry adiabatic lapse rate

Answer 12

parcels of dry air cool at a higher rate than the surrounding air

Question 13

saturated adiabatic lapse rate

Answer 13

the saturated air cools at a lower rate than the dry air because condensation is occuring so the air releases heat offsetting the cooling process
these changes apply within a lifted air parcel

Question 14

surface absorption

Answer 14

energy arriving at the surface has the potential to heat that surface, as heat is absorbed by it
the nature of the surface has an effect
if the surface can conduct heat rapidly into the lower layers of the soil its temperature will be low
if the heat is not carried away quickly it will be concentrated at the surface and result in high temperatures there

Question 15

latent heat

Answer 15

the turning of liquid water into water vapour
it consumes a considerable amount of energy
when water is present at the surface, a proportion of the incoming solar radiation will be used to evaporate it
that energy will not be available to raise local energy levels and temperatures

Question 16

sensible heat transfer

Answer 16

this describes the transfer of particles of air to or from the point at which the energy budget is being assessed
if relatively cold air moves in, energy may be taken from the surface creating an energy loss
if warm air rises from the surface to be replaced by cooler air, a loss will occur
this process is convective transfer and during the day it is responsible for removing energy from the surface and passit it to the air

Question 17

local nighttime energy budget

Answer 17

ther eis longwave radiation loss at night as often nights are cloudless so there is nothing to return the longwave radiation back to the surface
on cloudy night energy loss is reduced
at night water vapour in the air close to the ground can condense to form dew because the air is cooled by the cold surface
heat is released during this process
heat transferred by the sun to the surface during the day may be released back to the surface at night which can offset the nighttime cooling at the surface
sensible heat transfer still occurs and cold air moving into an area may reduce temperature whereas warm air mocing in will raise temperatures

Question 18

for clouds of fog/mist to form close to the ground

Answer 18

air must have been cooled close to the groun
-advection fog: as warm moist air passes over a cold surface it is chilled and condensation take splace as the temperature of the air is reduced and therefore it reaches dew point
-radiation fog: occurs when the ground loses heat at night by longwave radiation and therefore the air above it is cooled causing condensation and fog
more water vapour must have been added close to the ground
-this can occur over warm, wet surfaces like large lakes where water is evaporated from the warm surface of the lake and condenses in the cold air above to form fog
-for mist or fog to form, condensation nuclei are needed
-there are more common in urban or coastal areas so mist and fog are more common here

Question 19

tricell model

Answer 19

at the equator the sun shines directly and warms the earths surface
warm air rises creating an area of low pressure
in the subtropics this air sinks because it is colder and denser
it then returns to the tropics to replace the rising air
this circulation is the rising cell
the polar cell is a similar circulation
warmer air rises at lower latitudes and moves poleward
when the air reaches the polar areas, it has cooled considerable and descends as a cold, dry, high pressure area
the cell between these cells is the ferrel cell
it only exists due to the other 2 and mirrors their movement
it transfers warm air to high latitudes and shifts cold air back to the subtropics where it is warmed
the tri-cell model names the equator as the start of the sirculation
this is not actually the line of latitude by the true thermal equator
this moves depending on time of year

Question 20

wind and air pressure variation

Answer 20

rising air creates low pressure and air descending creates low pressure
winds blow from high to low pressure
they blow at an angle rather than straight due to the coriolis effect
this is the deflection of moving objects caused by the rotation of the earth
it deflects moving objects to the right of their course in the northern hemisphere and the left of their path in to southern hemisphere

Question 21

high and low pressure variations

Answer 21

air pressure varies depending on which hemisphere
air pressure varies more from season to season in the northern hemisphere compared to the southern hemisphere
this is because there is more ocean in the southern hemisphere and oceans do not vary in pressure or temperature as much as land does

Question 22

when does a parcel of air stop rising

Answer 22

air will continue to rise and cool until it reaches the same temperature as the surrounding air
this marks the top of cloud development

Question 23

stability and instability in air

Answer 23

stable conditions in the atmosphere exist when a rising parcel of air cools more quickly than the surrounding air
if air is displaced upwards it immediatley gets cooled, denser and sinks
because the air cools quickly it sinks and no clouds or precipitation is formed brining dry and calm weather
because the air is warmer than the surrounding air it continues to rise forming clouds and precipitation
conditional instability in the atmosphere exist when air parcels are stable if they are dry and unstable if they are saturated
air would be stable if it is dry and would sink to the ground but if it becomes saturated it is forced to rise and may become unstable

Question 24

frost

Answer 24

is a deposit of fine ice crystals on a surface
it occurs on cloud free nights when there has been radiation cooling to below freezing
water vapour condenses on these surfaces straight into a solid

Question 25

what is the atmosphere

Answer 25

an area of transparent gases surrounding the earth
the gases stretch 500-1000km above the earths urface
there are several layers ot the atmosphere
the area between layers is called a pause
weather occurs only in the lowest part of the earths atmosphere called the tropopause

Question 26

incoming radiation

Answer 26

insolation is shortave radiation that comes directly from the sun
some is reflected by clouds and lost to scattering
some is absorbed by gases in the atmosphere
some is absorbed by clouds
some is reflected by the earths surface
less than half actually reaches the earths surface to be abosrbed

Question 27

outgoing radiation

Answer 27

energy recieved by the earth is converted into heat energy when it reaches the surface
as the ground warms some is re-radiated as longwave radiation
some re-radiated energy is lost to space
evaporation and condensation account for a loss of some of hte heat energy from the earth as heat energy is used up when the liquid is turned into vapour
some of the re-rdadiation energy is absorbed by clouds, water vapour and CO2

Question 28

local daytime energy budget

Answer 28

the global energy budget refers to the whole planets energy system
local energy budgets exist for individual areas of the planet
the 2 different type of energy budget are global and local
the local energy budget shows the gain or loss of energy for any one particular location on the earths surface
this is how energy is lost and gained during the day
the budget assumes that the ground is horizontal and covered in grass

Question 29

dew

Answer 29

is the name for condensation of water on a surface
this means when water vpaour in the air has turned into water droplets on a surface
this normally occurs because the surfac eis cold and has causeed the air to cool and therefore become saturated and so condensation has occurred

Question 30

winds and air pressure

Answer 30

changes in air pressure make winds blow
air moves from areas of high pressure to areas of low pressure and this produces winds

Question 31

atmospheric circulation

Answer 31

the atmosphere is circulating around the planet and does not stay still
the causes of this ciruclation is due to pressure difference
air pressure differences are due to the energy given out by the sun to different latitudes

Question 32

differences in climate due to latitude

Answer 32

the highest temperatures are recorded at the low latitudes in the tropics north and south of the equator
there is a decrease in temperature between the equator and the poles
this is because at the equator the sun shines directly from overhead in the sky and therefore is concentrated on a small area whereas at the poles the suns energy is scattered over a lrger area so is less concentrated

Question 33

differences in climate due to altitude

Answer 33

air temperatures decrease with altitude
this is because when air is at the bottom of mountains and hills it is underneath more air pushing down on it
this makes the air denser and therefore warmer
as altitude increases so the pressure on the air is reduced and the air becomes less dense and cooler

Question 34

differences in climate due to prevailing winds and air pressure

Answer 34

air rises at the equator as the sun is hottest here which makes the air warm enough to warm
as the air rises it makes cumulonimbus clouds and it cools down
once it has cooled it becomes denser so it sinks down making high pressure areas with no cloud
these areas are hot and dry due to the sinking are and are deserts
in temperate zones there is cold air circulating from polar regions where the suns heat is not felt as much, meeting with warm air from desert regions
the warm and cold air meeting in temperate regions creates rai clouds and bings mild to cool temperatures

Question 35

difference sin climate due to ocean currents

Answer 35

warm ocean currents from hotter areas of the globe such as the equator raise temperatures
cold currents form the polar regions can cool temperatures
ocean currents tend to flow in the same direction all year round so temperatues are regularly affected by them in the same places

Question 36

differences in climate due to distance from the sea

Answer 36

land heats more quickly and cools more quickly than the sea
distance from the sea can affect and areas climate
water takes longer to heat in the summer months than areas of land so by the coast in summer, temperatures are cooler due to the colder water temperatures
however inland it is warmer in the summer than coastal areas as the land around has already heated up quickly
in winter the opposite occurs
places by the coast are warmer as they have taken longer to heat up over summer but also take longer to cool so keep coastal areas warmer
inland the land cools quickly in winter and keeps the area colder

Question 37

what happens during evaporation

Answer 37

heat energy is absorbed
the heat used passes into the water and is known as latent heat

Question 38

why does evaporation occur?

Answer 38

water vapour in the atmosphere exerts a pressure on the surrounding bodies of water/air and vapour pressure
evporatino occurs when vapour pressure of a water surface exceeds that in the atmosphere
evporation aims to equalise the pressure
it depends on humidity, supply of heat and wind strength
if air is dry around a body of water then strong evporation occurs
the hotter the air the more evaporation takes place as the vapour pressure increases
under calm conditions less evaporation takes place

Question 39

what happens during condensation?

Answer 39

occurs when an air mass becomes fully saturated after a lot of evporation or the temperature of the air mass drops do that the dew point is reached
dew point is the point at which air is saturated
this is more common and can occur in 3 ways:
-radiation cooling of that air
-contact cooling of the air when it rests over a cold surface
-cooling of air when it rises
very hard to achieve in pure air
it often requires tiny particles onto which that vapour can condense
in the lower atmosphere these are quite common

Question 40

how does precipitation form?

Answer 40

water vpaour in the air is condensed into tiny water dorpllets forming clouds
if these droplets join together to form large droplets they get heavier
when they are heavy enough to overcome ascending air currents they fall as rain
the droplets must get large enough to form rain drops and there are several theories on how this happens
-coalescence by sweeping where a falling droplet sweeps up others in its path
-growth of droplets by electrical attraction to each other
-condensation around nuclei

Question 41

cloud types

Answer 41

a cloud is a visible mass of condensed water vapour or ice particles floating in the atmosphere typically high above the ground
they are classified according to altitude, shape and if they bring precipitation or not
-below 2000m make of water. between 2000-6000m mixture of ice and water. above 6000m ice crystals
-cumulus are heavy, lumpy, fluffy clouds. cirrus looks like wispy locks of hair. stratus look like vast sheets
-nimbus bring precipitation. nimbus clouds are nimbostratus and cumulonimbus. nimbostratus are flat wide rain clouds which do not bring thunder or lightening. cumulonimbus are taller, dense which can extend higher in the air and bring thunderstorms

Question 42

orographic rainfall

Answer 42

air is forced to rise over a barrier such as a mountain
air it rises it cools, condenses and forms rain
often there is a rain shadow effect where the leeward slope receives very little rain

Question 43

convectional rainfall

Answer 43

when land becomes very hot it heats the air above it
this air expands and rises
as it rises it cools and condensation takes place
if it continues to rise rain will fall
it is very common in tropical areas

Question 44

frontal rainfall

Answer 44

frontal rainfall occurs when warm air meets cold air at a front
the warm air is lighter so rises above the colder denser air
as it rises it cools and condenses to form rain
it is most common in mid latitudes where warm tropical air meets cold polar air

Question 45

hail

Answer 45

is frozen pellets of rain formed by raindrops being carried up and down in vertical air currents in cumulonimbus clouds
once it is large enough it escapes from the air currents downwards from the cloud towards the ground

Question 46

snow and sleet

Answer 46

snow is frozen precipitation
snow crystals form when temperature is below freezing and water vapour is converted staright into a solid
every level of the troposphere must be below freezing so the snow does not melt on its way down

Question 47

the greenhouse effect

Answer 47

natural process
earth would be too cold without it
the earth is surrounded by a thin layer of greenhouse gases which sit around the earth
shortwave radiation from the sun travels through the layer
it is re-radiated by the earth as longwave radiation
some if the longwave radiation is re-emitted by the layer of greenhouse gases
some if the longwave radiation is allowed to escape back out to space through the layer to stop the planet getting too hot
1. shortwave radiation passes through the clear atmosphere
2. most radiation is absorbed by the earth surface and warms it
3. some solar radiation is reflected by the earth and the atmosphere
4. infrared radiation is emitted from the earths surface
5. some if the infrared radiation passes through the atmosphere and some is absorbed and re-emitted in all directions by greenhouse gas molecules
6. the effect of this is to warm the earths surface and the lower atmosphere

Question 48

the enhanced greenhouse effect

Answer 48

caused by humans
happens when extra gases produced have made the amounts of greenhouse gases in the atmosphere more concentrated
this layer stops more of the longwave radiation escaping to space and remits more of it toward the earth
the planet is heated because of this

Question 49

impacts of global warming

Answer 49

depend on the amount of change the climate undergoes
falling crop yields in many areas especially developing regions
possibly rising yields in some high latitude regions
falling yields in many developed regions
small mountain glaciers disappear-water supplies threatened
significant decreases in water availability
sea level rise threatens major cities
extensive damage to coral reefs
rising number of species face extinction
rising intensity of storms, forest fires, droughts, flooding and heatwaves
increasing risk of dangerous feedbacks and abrupt, large scale shifts in the climate system

Question 50

urban climates

Answer 50

result from extra sources of heat released form industry, commercial and residential buildings as well as from vehicles, concrete, glass and tarmax which all act very differently to natural soil and vegetation
they are hotter
there is less water vapour and lower humidity
there are more intense storms
there is reduced visibility
there are slower winds in general but there can be wind tunnelling
there is less snow

Question 51

why do urban climates occur?

Answer 51

hotter than surrounding areas due to grater surface area in urban areas to absorb heat, albedo of tarmac and concrete is lower than grass areas so less insolation is reflected, buildings absorb large quantities of heat and release them at night, little energy is used for EVT so more is available to heat the atmosphere, pollutant help trap radiation
less moisture due to a lack of vegetation so less transpiration and high drainage density which remove water
more intense storms due to greater instability and stronger convection above urban areas
less snowfall due to higher temperatures
slower winds unless tunnelld between buildings. wind is deflected by buildings

Question 52

weather and climaye

Answer 52

weather is the shortterm conditions of the atmosphere
climate is the longer term average conditions in the atmosphere

Question 53

the earths energu budget

Answer 53

the atmosphere has an energy budget
it receives energy from the sun and earth
it loses energy to space
if it loses more energy than it gains the atmosphere cools down
if it gains more energy that it loses it heat up

Question 54

insolation

Answer 54

atmosphere main energy input which is strongly influenced by cloud cover and latitude
at the equator the suns rays are more concentrated than at the poles

Question 55

reflected solar radiation

Answer 55

the proportion of reflected solar radiation varies greatly with the nature of the surface
the degree of reflection is expressed as either a fraction on a scale of 0-1 or as a percentage
this fraction is referred to as the albedo of the surface which is the proportion of sunlight reflected from a surface
fresh snow and ice have the highest albedos
oceans surfaces absorb most sunlight so have low albedos

Question 56

latitudinal patterns of radiation excess and deficits

Answer 56

means which areas of the globe get more of the suns energy than others
the amount of the suns energy that is received by an area is the net radiation
net radiation is what is left after how much radiation entered an area and how much was lost
if net radiation os 0 then the energy budget is balanced and an area neither warms or cools
areas closer to the equator receive more radiation than those closer to the poles for 2 reasons
1. insolation is more concentrated near the equator but dispersed near poles
2. insolation near poles has to pass through a greater amount of atmosphere and there is more chance of it being reflected back out to space
a balance is achieved by the horizontal transfer of energy from the equator to the poles by wind and ocean currents to compensate for differences in global insolation
if there was no energy transfer the poles would be 25C colder than they are now

Question 57

air pressure

Answer 57

the gases in the atmosphere press down on the earths surface, exerting a force called air pressure
it is differences in air pressure that cause weather in the atmosphere

Question 58

how does moisture exist in the atmosphere

Answer 58

vapur
liquid
solid

Question 59

how does moisture change states

Answer 59

evaporation-change from a liquid to a vapour
condensation-change from a vapour to a liquid
melting-change from a solid to a liquid
sublimation0direct change from a solid to a gas omitting the liquid stage
freezing-change from a liquid to a solid

Question 60

humidity

Answer 60

absolute humidity refers to the amount of water vapour in the atmosphere
relative humidity is the amount of water vapour present in the atmosphere expressed as a percentage of the ,aximum amount of water the air can hold at that temperature
completely saturated air will have a humidity of 100%

Question 61

why does relative humidity change

Answer 61

as air is warmed the amount of moisture it can hold increases so its new moisture is added to a pocket of watm air as it warms, its relative humidity will decreases

Question 62

precipitation

Answer 62

refers to all forms of deposition of moisture from the atmosphere in either solid or liquid states
it includes rain, hail, snow, sleet and dew
the fall of water, ice or snow deposited on the surface of the earth from the atmosphere
there are 3 types
-orographic, convectional and frontal
they all occur because air is forced to rise

Question 63

the human impact on atmosphere and weather

Answer 63

climate change is the process of the average global temperature rising
this warming is occurring because the earths energy budget falls out of balance
the earths energy budget myst be balanced or temperature will change
the same amount of shortwave radiation that enters the earths atmosphere must leave as longwave radiation
climate change is caused by an enhancement of a natural process called the greenhouse effect
without the greenhouse effect, life could not survive on earth

Question 64

the greenhouse gases

Answer 64

CO2
-burning fossil fuels, deforestation, road vehicles
methane
-cattle, natural wetland and paddy fields, bogs trapped in permafrost will melt and release more methane, biomass burning
nitrous oxide
-human activities, burning of fossil fuels
CFC’s
-aerosol propellants, solvents, refrigerators, foam blowing agents