the atmosphere part 1 Flashcards
state 3 essentials to life that the atmosphere provides us with
protection from solar radiation / gas resources / transfer of energy and water around the globe
state proportion of air and importance for life of nitrogen
78% / used in proteins
state proportion of air and importance for life of oxygen
21% / used in aerobic respiration
state proportion of air and importance for life of carbon dioxide
0.04% / used in photosynthesis
state importance for life of methane
some chemoautotrophs use methane as a source of carbon, important for early life and in deep oceans
state importance for life of ozone
absorbs UV light in the stratosphere
what does the magnetosphere do and what would happen if we didn’t have it
provides protection from radiation and deflects harmful solar wind - solar wind would blow away the earth’s atmosphere
what compounds were in earths prebiotic atmosphere compared to now (in order of amount biggest to smallest)
prebiotic: CO2 N2 H2O {NH3 CH4 H2}
modern: N2 O2 H2O {CO2 AR CH4}
give an example of dynamic equilibrium to do with photosynthesis
uses carbon dioxide at the same rate respiration releases it, so in the long term no overall change to atmospheric carbon dioxide concentration
list the 4 layers of the atmosphere in order of those closest to the ground to that furthest away
troposphere, stratosphere, mesosphere, thermosphere
what warms the troposphere
GREENHOUSE GASES. visible light from sun is transmitted through atmosphere and absorbed by earths surface, some of which is radiated back into the atmosphere from surface as INFRARED RADIATION, longer wavelength, heating effect, infrared is absorbed by greenhouse gases
why does infrared result in a larger heating effect
it has a longer wavelength, is absorbed by greenhouse gases which then vibrate and re radiate in all directions, accumulating heat energy
why does the temp decrease up the troposphere
less infrared. because the source of infrared radiation is from the visible light absorbed by the earths surface and radiated as infrared so the further away from the surface the less infrared = lower temp
explain the trend in temperature in the stratosphere
higher temperature at the top of the stratosphere as UV intensity is higher, bc UV comes from the sun so more UV absorbed so more reactions take place. absorbed UV initially stored as chemical energy in products of reactions, some energy is released as heat
explain the trend in temperature in the mesosphere
temperature decreases up the mesosphere. because you get further away from the heat of the stratosphere
explain the trend in temperature in the thermosphere
temperature increases up the thermosphere. due to high energy solar radiation absorbed by air particles, radiation is more intense up the top, where incoming solar radiation first arrives
why is the tropopause at its highest temp around the earth during the day at the equator
high intensity of sunlight warms the troposphere the most here, causing troposphere to become less dense and expand
why is the atmosphere very dry beyond the troposphere
most water falls as precipitation in the troposphere
describe the trend in pressure across the atmosphere and why
its higher at the bottom of the troposphere because gravity pulls air molecules towards the surface
what does nuclear fusion in the sun do
releases enormous amounts of energy as electromagnetic radiation, some reaches earth
what happens to the electromagnetic radiation that reaches earth
some is absorbed into the atmosphere eg UV in ozone or stratosphere also greenhouse gases absorb visible light and infrared / some light is reflected or absorbed by clouds
how much insolation is absorbed by the earth surface and where does the rest of it go
51% / reflected by clouds, atmosphere, surface / absorbed by atmosphere, clouds / carried to clouds and atmosphere by latent heat of vaporisation
high albedo means cooler or hotter temperatures
cooler temperatures (high albedo=cooler temperatures)
name the 3 surfaces that have highest albedo (highest cooling temperature)
snow, desert sands, concrete
what does it mean if something has a high albedo
it reflects lots of solar radiation
name the bottom 3 surfaces that have the lowest albedo
water, tropical rainforest, tarmac
what does the mesosphere protect us from
meteorites
why don’t you feel the heat in the thermosphere
because the air pressure in so low
in what 6 ways does the atmosphere support life
gases for natural processes / absorption of electromagnetic radiation from the sun / delaying the escape of infrared energy / heat distribution / ocean currents / transport of water vapour
how does the atmosphere support life with ocean currents
winds blowing over the ocean creates current that distributes heat by carrying warm water from tropical areas to higher latitudes, North Atlantic Conveyor
