atmosphere Flashcards
5 atmosphere layers
tropo, strato, meso, thermo, exo
troposphere
7-20km above sea level, height depends on lat, season and time of day. all life, weather, 90% all air, temp gradient decrease with altitude til tropopause reached, air pressure and density decreases with altitude, most water droplets=clouds, heated from earth’s surface that radiates longwave ir into troposphere.
why is troposphere highest alt at equator
thermal expansion at the equator and thermal contraction at the poles. equator is warmer making air thicker, convection currents of air expand the thickness of the troposphere at the poles.
thermal expansion
when an object expands due to change in temperature. molecules move faster and take up more space.
thermal contraction
objects decreasing in size due to changes in temp.
what is the atmosphere
the layer of gas that surrounds the planet held in place by the planet’s gravity
stratosphere
2nd layer, altitude of 50km, stable and very dry, air is thinning, ozone layer, temp increase with altitude, nascreous clouds occuring in the lower stratosphere
ozone layer
region within stratosphere, high concentration of ozone that is created when high energy UV strikes a normal o2 molecule. extends 15-35km above sea level, absorbs harmful rays UV from the sun before it reached the ground, o3 molecules absorb uv and reradiate the energy as heat warming the stratosphere. ozone hole caused by chemicals released by humans
mesophere
50km-90km above sea level, temp decrease with altitude, solar energy isnt absorbed as air is thin, meteors burn here, air from troposphere can reach carrying energy. noctilucent clouds form over the poles, the highest clouds. coldest part of earth’s atmos at the top
thermosphere
90km alt up, temp rises sharply in lower thermosphere due to solar heating, steadily continues to increase with alt, auroras occur, hottest layer direct contact with solar energy and radiation
exosphere
thin layer where the atmosphere merges into space
ionosphere
in thermosphere, magnetic field, less than0.1% mass of earth atmos, upper atmosphere ionized by solrat, solar energy so strong it breaks apart molecules, so electrones float around with molecules which have lost or gained electrons. make long distance radio communication possible. auroras occur here due to collision of solar wind
the pauses
transition boundaries between the layers due to temp contrasts
aerosols / particulates
minute solid and liquid particles suspended in the atmosphere. larger particles scatter and absorb sunlight
desert dust
minute grains of minerals from deserts blown to high altitudes by instense dust storms, absorb and scatter sunlight
volcanic aerosols (large scale eruptions
blasts gases and particles ike ash and sulfur dioxide into the stratosphere with long term affects on the climate (years to centuries). long term warming due to enhance greenhouse effect. high winds in stratosphere spread ash and aerosols all around the globe, only removed when catch into circulation cell go back to troposphere and get rained out
volcanic aerosols (small scale eruptions)
blast ash plumes into troposphere where they may lower visibility, affect day and night temps, a cooling effect on short term earth climate, rained out within a coupel of weeks.
clouds
mainly air with a whole lot of very tiny droplets of water suspended in the air. regulates planet temp, cooling earth as they reflect suns shortwave solar energy. others warm due to trapping longwave heat energy emited by earth surface (so2 etc). precipitations occurs when several drops combin and fall due to gravity
cloud formation
water vapour (gas) in the air evaporated from oceans, lakes rivers, wet grounds and transpiration + aerosols + air rising and cooling. the water vapour and aerosols bump into e/o, warm air contains more water vapour, when air cools water vapour sticks to aerosols when they collide and condense to liquid water. the water droplets stick together with other droplets forming clouds.
cloud condensation nuclei (dew point)
the temperature at which a parcel of air must be cooled to reach saturation (constant humidity and pressure). the amount of water vapour air can hold varies with temp, warmer air a greater ability. if air cools it cant hold moisture any logner forcing water vapour to condense into clouds, mist or fog etc. relative to humidity. water is only seen when condenses (as gas)
step by step cloud formation
form when air forced over a barrier such as a mountain where air cools and it often rains. solar energy heats the ground short wave rad, conduction with the air above warming the air, the warm air rises due to pressure gradients, convection between the air, the rising air cools and condenses, the dew point is reached and clouds form
air masses rising
clouds from when air at the surface is forced to rise, air moves from high to low pressure and when this air meets in the center, there is no where else to go but up, wind moves to center from all directions.
cold front cloud formation
cold front develops warm air ahead of the front, pushes up over the top of the cold air. warm air is lighter than cold air, warm air rises, cools and moisture in the air condenses. thunderstorms occur
warm front cloud formation
warm air mass slides over cold air mass pushing warm air upwards forming clouds. low stratus clouds occur
energy from the sun
radiation, conduction, convection.
infrared heat
energy from the sun we cant see, long wavelength, absorbed and reradiated from the ground to the atmosphre
ultraviolet
energy from the sun we cant see, very shortwave
visible light
energy from the sun with short wavelength that is absorbed by all objects on earth’s surface
incoming energy
shortwave radiation, small amount of sol rat reflected by surface, more reflected by clouds
outgoing energy
outgoing longwave radiation, reflected back to surface by clouds or move through clouds to go back to space
greenhouse gases
trap heat in the atmosphere and radiate it back to earth’s surface warming earth. excess ghgs causing enhanced greenhouse effect
uneven heating on earth
earth tilted on axis at 23.5degrees, rotates every 24 hours. sun shines more directly on equator than poles, more solar energy absorbed at equator then poles resulting in more heat IR at tropics causing convection currents
sensible heat
the amount of heat/energy required to change the temperature of the substance without changing the phase of the substsance. heat causing change in temperature
latent heat
energy absorbed or released by a substance during a change in its physical state occuring without changing its temperature (other than the temperature of the outside environment)
latent heat absorbed
energy taken from the environment when a solid melts into liquid or liquid evaporates into gas
latent heat released
energy released into the environment when gas condensates into liquid and when liquid freezes into solid
albedo
light coloured surfaces reflecting the light that hits them (high albedo), or dark coloured surfaces absorb most of the light (low albedo)
earth’s thermostat
ocean atmosphere land and life work together to recycle everything except energy. maintaing a stable climate
transport of matter (water)
moved around by convection cells and water, water cycle also moves water, moves between earth surface and atmosphere
transport of matter (gas)
transported by temperature and pressure differences in the air, causing winds
transport of matter (aerosols)
carried into atmosphere by winds and transported for 1000s of kms. when aerosols enter stratosphere they stay there for years
warm air
low pressure as it expands, less dense and rises. as it rises it cools and cannot hold as much water leading to clouds and precipitation. areas with warm air rising are wet
convection cells
transfer heat, contain major wind at the bottom of each cell
hadley cells
low pressure at the equator high pressure at 30degree N and S. tropics air is warm and moist and it rises and cools, cannot sink back cause of rising air beneath. the rising air reaches the trop of the troposphere and then moves north or south and sinks at 30 degrees. the returning air causes trade winds that blow towards the west due to coriolis
trade wind
the winds formed by the returning air at the bottom of the hadley cell. north east trade winds and south east trade winds
ITCZ
inter tropical convergence zone, the doldrums. it moves with seasons further south in SH summer and north is SH winter
polar cell
high pressure at 90degrees low pressure at 60degrees. at the poles, cold and very dense air sinks moving towards the equator. around 60degrees air is less dense meeting warm air from the equator. some air heats up and rises forming a polar cell
polar easterly winds
formed by the dense air moving towards the equator, blowing towards the west cause of the coriolis effect
ferrel cell
high pressure at 30degrees, low pressure at 60degrees. air that sinks at 30 moves to the low pressure region of 60. at 60, warm winds from the equator meet the cooler polar winds forming warm air that rises as it is less dense resulting in low pressure, forming the less well formed cell.
moist mid latitude westerly winds
ferrel cell, coriolis effect forms them to blow NW or SW from 30 to 60 degrees
jet stream
relatively narrow belts of high speed winds that blow in the upper troposphere, forming at the boundaries of adjacent air masses with significant different in temperature.
coriolis effect
the effect of the earth’s spin, earth rotates about the exis towards the east once every 24 hours, objects on the surface rotate as well (ocean atmosphere). the speed of movement is the highest at equator decreases gradually north and south till it gets to zero at poles. the coriolis effect is greatest near the poles decreases towards equator. deflection of wind greatest at poles. latitudes increasing and speed of earth rotation decreasing affecting coriolis
wind
caused by difference in atmospheric pressure moving from high to low pressure, the greater the difference in pressure the stronger the winds
pressure zone
marks boundaries of wind belts. zones and belts move north during southern winter and south during southern summer
main pressure zones
polar high, polar front, subtropical high, equatorial low (itcz)
tropics and itcz
global climate zone, responses to low or high pressure regions. sun shines directly down so high temp, low air pressure, high evaporation and rainfall. no wind due to warm rising air creating low pressure, warm and wet (doldrum)
subtropical high pressure belts (horse lats)
global climate zone, two zones at latitude 30n and s. warm humid air from itcz comes back down to earth and cold dense and dry. high pressure zones with descending air and low rainfall, hot deserts here
subpolar low pressure belts
global climate zone. two zones at latitude 60 n and s. low air density, low pressure, ascending air and high rainfall. wet area
the poles
global climate zone. 90 n and s. very dry cold air at high pressure. descending air. dry region
sea breezes
land warms more repidly than water during the day as water has a higher heat capacity. air above the land warms through conduction, becoming less dense and rises drawing cooler air landward from the sea. the pressure gradient between the sea and land causes winds to bloe from the sea onto the land
land breeze
at night, cool heavy air from the land flows to the sea because now the air on top of the sea is warmer than the land as land loses heat faster than water does. pressure gradient weaker than during the day so wind isnt as strong.
radiation
energy moving from one place to another in a form of waves or particles
conduction
heat moving from one object to another through direct touch, collision of neighbouring atoms and molecules
convection
movement of particles through a substance transporting heat energy from hotter areas to cooler areas. through air and liquid currents
the water cycle
water needs to be replenished, purified and circulated again to perform functions after being used. recycles water. moving water through the three faces over the 4 spheres (atmo, geo, hydro, bio). regulates temp, changes weather, creates rain, converts rock to soil, circulates minerals, creates geographical features
evaporation
water changes from liquid to gas by evaporation, water vapour enters atmosphere. energy is required. due to latent heat energy is taken from atmosphere to evaporate liquid water cooling surrounding air
transpiration
evaporation of water through plant membrane
condensation
substance changes from water vapour to liquid water, heat returned to atmosphere, latent heat released.
dew point temperature
air becomes saturated when the air containing water vapour rises into atmosphere, expands and cools. cool air cannot hold as much water vapour as warm air so water vapour condenses into liquid water. varies from day, lcoation, temp of water and air. causes clouds, rain, snow and other precipitation. when cocurs near ground causes few fog frost
precipitation
water that falls from the atmosphere to the surface. condensed water droplets (clouds) eventually grow large enough where they cannot stay suspended in the atmosphere so they fall
runoff and groundwater
precipitation falls to the surface either to be absorbed into ground and flow into streams where they converge into rivers and flow back to the ocean
water is stored in:
lakes, ocean, rivers, underground, amosphere, soil
water transported by
convection currents, wind, ocean currents, evaporation and precipitation, living organisms, subduction
subduction
process when two tectonic plates meet at convergent boundaries and one moves under the other due to gravity and differences in density
solid water
water molecules packed together, ice doesnt change shape
liquid water
water molecules dont cling together very tightly and molecules move around each other
gas water vapour
water molecules move very rapidly and are not bound to each other.
water chemistry
h and o atoms joined by covalent bond (strong bond where electrons are shared). electrons not shared equally so h has a weaker positive charge and o has a weaker negative charge making water polar. cohesion is when the molecules cling together due to the attraction pos to neg neg to pos forming hydrogen bonds
ice density
ice less dense than liquid water and floats on top. hydrogen bonds hold water molecules apart in ice. ice insulates water
capillary action
cohesion of water causing water to move upwards in small biological or physical spaces like how water gets from root to leaves
surface tension
cohesion of water also causes surface tension, invisible skin, some insects can walk on water cause of this
water’s specific heat capacity
the amount of heat needed to raise waters temperature a certain amount. a high specific heat, absorbs lots of heat before getting hot and holding that heat longer.
solar energy
sun ehats the earths surface unevenly, determining the earth’s climate
earth tilt
different parts receive different amounts of solar energy at different times, determining earths climate
wind formation
due to convection cells and local conditions determine the earths climate
pressure differences
that cause winds determine the earths climate
coriolis effect
winds and ocean currents deflected clockwise in nh and anticlockwise in sh that determine earths climate
weather
a mixture of events on any day. the short term atmospheric conditions over a short period of time. varies from place to place
climate
is what you expect, the average conditions found in the atmosphere over a longer period of time
isobar
on weather maps show what is happening at a set time on the earth’s surface, joining together places with the same air pressure. wind blows directly along isobars, the general wind flow
localized variations
chains of mountains that distort isobars crossing them
highs / anticyclone
when isobards enclose an area of high pressure called a high or anticyclone
lows / depression
when isobars enclose area of low pressure
front
marks a boundary between two air masses
cold front
forms when cold air pushes under warmer air ahead of it, forcing warm air upwards making clouds and areas of rain. as a cold front passes by rain clears but air temp drops and wind changes direction
warm front
rises over cooler air often bringing prolonged steady rain. as a warm front passes rain becomes patchy, air temp may rise and wind changes direction
orographic rainfall and rain shadow effect
process causing higher volumes of rainfall on one side of a mountain range than the other. air forced up very quickly over a short distance, clouds form and heavy rain or snow falls
katabatic winds / mountain breeze
mountain cools down, air becomes heavier so it descends from mountain to valley
anabatic winds / valley winds
sun warms mountain, air is lighter and ascends. rising from valley to moutain
cloud saturation
where the parcel of air is unable to hold all the water it contains in water form, so it stats to condense into liquid or solid, water vapour condenses on pieces of dust, pollen and other condensation nuclei
condensation nuclei
particles which water vapour condenses onto to form clouds
low clouds
scatter more solar radiation than they absorb infrared radiation, a cooling effect due to the high albedo reflecting sunlight from earth surface
high clouds
are thing, transparent to sunlight, reflect less solar radiation and trap outgoing longwave infrared radation (heat) rerediated from the earth’s surface, warming the earth
outgoing longwave radiation
electromagnetic thermal radiation emitted by earth’s surface, atmosphere and clouds. 10% of this radiation passes through atmospherer into space, rest is absorbed by (high) clouds and ghgs
incoming shortwave radiation
radiant energy produced by the sun with wavelengths ranging from infrared through visible to ultraviolet. the hotter the object the shorter the wavelength which is why radiation from the sun is shortwave and radiation from earth is longwave as earth is cooler. penetrates the surface of the plant and absorbed, some reflected by clouds, some absorbed by atmos in ozone layer (UV rays)
ghgs
absorb longwave radiation not incoming shortwave because they interact with light at different wavelengths. they absorb infrared longwavelength (absorbed from earth’s surface) and reradiate the radiation back to warm the earth
cfcs
ozone destroying chemicals, causing ozone hole
the main wind belts
polar eastieries of the polar cells, westerlies of the ferrel cells, trade winds of the hadley cells
the 4 high and low pressure regions
polar high at the poles, polar front at 60 degrees, subtropical high at 30, equatorial low (itcz) at 0.
4 global climatic zones
tropics, itcz /doldrums, subtropical high pressure belts (horse lats), the poles
air pressure
atmospheric pressure is the mass of air or the force exerted by air on a certain area. the higher you get the lower air pressure cause fewer molecules. rising air causes low pressure sinking air high pressure
