Atmo Summary

8/13/2019 Atmo Summary

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,ressure di$$erence due to denser air 2more pressure4 s. lessdense air 2less pressure4" une/ual heating o$ earth

o +oriolis $orce%e$lects pressure gradient $orce due to rotating e$$ect o$ Earth!tronger at poles than at e/uator

&$$ects wind direction" a$$ected by wind speedo 9riction: present at sur$ace but absent $or $low alo$to Geostrophic winds: parallel $lows to isobars with elocities proportional

to pressure gradient $orceo !ur$ace winds

ind speed drops due to $riction ' pressure gradient $orce nota$$ected but +oriolis $orce a$$ected ' pressure gradient $orcestronger so wind direction changes ' wind mo es at an angleacross isobars towards low pressure area

The ma;or wind beltso across e/uator

Global oceanic circulation 215 o$ earths heat transport4 hen atmosphere and water in contact" energy passed to water through

$riction %rag e(erted by winds cause water sur$ace to mo e

!easonal climatic ariations Re olution and tilt at =.3 to the perpendicular ' solstices and e/uino(es %aylight hours determined by circle o$ illumination

=


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=. ?pper &tmosphere ind and @et !treams

)rigin o$ ;et streams Great temperature contrasts at sur$ace produce great pressure di$$erences

alo$t ' increase wind speed due to pressure gradient $orce

,olar ;et stream +hanges speed and location with seasonal contrasts eanders

eather +yclones

o %ue to ridges and troughs as ;et stream meanders across Earth"locations at lower latitudes may e(perience colder temperature thanthose o$ higher latitudes

o o es north" drags air $rom below and speeds up ' low pressureregion at sur$ace due to rising air ' surrounding air will mo e in ananticloc#wise direction

o !peed and path o$ ;et stream a$$ects intensity o$ cycloneo Eg. 1A C ?D big hurricane because it was in the path o$ ;et stream

%roughts due to persistence o$ high pressure in an area +an ha e short term cyclonic ariations as cyclone redistributes heat '

originally higher latitudes cooler but it becomes warmer

. ,recipitation 9ormation

+onditions !aturation: air cooled below dew point 5 holds su$$icient water +ondensation nuclei" without which relati e humidity must be 188F to

produce clouds

En ironmental lapse rate: rate at which temperature decreases with height2about .3 +5#m4

&tmospheric stability 5 instability %ependent on intensity o$ sur$ace heating ' impact on %&0R 5 !&0R !table i$ %&0R 5 !&0R $aster than E0R ' air cannot rise ?nstable i$ %&0R 5 !&0R slower than E0R ' air can rise +onditional instability i$ %&0R slower but !&0R $aster than E0R or ice ersa %etermined by whether air parcel can rise through surrounding air


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&ir li$ting mechanisms +on ecti e li$ting due to instability o$ air

o +aused by strong sur$ace heating due to sur$ace irregularities 2eg.dar# s. light sur$ace4

o But clouds $ormed at this height 2condensation height4 limited because

o$ instability because sur$ace heating only lasts $or $irst $ew #m )rographic li$ting

o indward: adiabatic cooling $rom lots o$ cloudso 0eeward: adiabatic heating and already released precipitationo 9ormation o$ rain shadow desert eg. ,atagonia desert in &rgentina

. &d erse eather +onditions ' Tropical +yclones

9ormation C + ocean" su$$icient twist arm sea heats air abo e ' low pressure area $ormed ' wind rushes and

spirals in ' releases heat and moisture be$ore descending Rising air cools producing cumulonimbus clouds ' cloud tops carried

outwards !el$-sustaining heat energy created: large amounts o$ energy trans$erred as

warm water e aporates ' release o$ latent heat as it rains ' more windrushing in to low pressure area

+haracteristics 3 - 8

@une to %ecember in northern hemisphere" @an to arch in southernhemisphere

o es westwards initially due to easterly trade winds" but as storm intensityincreases it mo es polewards 2in$luenced by mid-latitude westerlies to mo eeastwards4

Eye 2highest pressure4 Eye wall: sudden drop in pressure" rapidness results in e(treme weather

conditions. Velocity increases because near the core due to conser ation o$angular momentum

%issipation +annot support large-scale $low alo$t 6o warm water body


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o ,iling up o$ water as wind drags sur$ace waters $orwardo 0ow pressure: e ery millibar drop" sea le el increases by 1 cmo Eg. Bangladesh H m abo e sea le el

ind damageo &$$ects greater area than storm surgeo Eg.


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o But not e ery pollen can be identi$ied to species le elo But not all species produce the same number o$ pollen

!cots pine large /uantities" but beech small /uantities andusually under-represented

Tree ring analysiso Thic#er ' more $a ourable temperature 5 moisture

+auses 2tal#ing about 6orthern hemisphere4 Eccentricity 2shape o$ orbit4

o 6ow Earth =F closer to sun on @an than on @uly ' F more solarenergy recei ed in @an than in @uly

o hen ery eccentric" =F - =8F more solar energyo inter warmer: temperature increase" can hold more moisture" more

precipitation and summer cooler: less snow melt ' glacier e(tension )bli/uity: angle o$ tilt

o

+urrently at =.3

but can change between .1

to .3

- a$$ectsseasonal contrast ,recession o$ e/uino(es

o 6ow tilted towards 6orth !tar but may switch to !tar Vega ' winter when Earth $urthest $rom sun and summer when Earth nearer to sun 'greater seasonal contrast

!olar ariabilityo !un spots: magnetic storms on suns sur$ace that e(tend deep into

interioro &ssociated with increase solar outputo +orresponds to 0ittle 7ce &ge but not to other locations climates

Volcanic acti ityo Release o$ aerosols into stratosphere that can remain $or yearso 7ncrease albedo o er areao 7ncrease cloud albedo because aerosols act as condensation nuclei

ma#ing clouds densero Eg. 1 13 eruption o$ t Tambora" 7ndonesia ' year without summer

,late tectonicso !low mo ement only accounts $or temperature changes o er great

span o$ geologic time

. +limate o$ the +ities

?rban heat island e$$ect %i$$erences within a locali*ed area greatest in winter" late e enings 5 night"

considering minimum temperature eg. in 0ondon" Dew had C8 more $rost $reedays than nearby rural isley

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+auseso +hanges in thermal capacity

Buildings able to store more heat and release more in the nightcompared to shallow layers o$ soil

o !ensible and latent heat trans$er?rbani*ation results in water being drained out /uic#ly ' surplusenergy goes to increase temperature rather than e aporation

o The urban structure0ower albedo than natural sur$ace!ome insolation absorbed and some scattered as di$$useradiation ' stri#es another sur$ace and process repeats


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Reduction in solar radiation: greater albedo and low angle o$ sun passesthrough more pollutants

0ower relati e humidity: high temperature and less moisture +ountry bree*e: wind blowing in $rom surroundings and upward air mo ement

in cities

A. The Enhanced Greenhouse E$$ect and Global arming

Greenhouse gases +arbon dio(ide

o Burning o$ $ossil $uels: A8F northern hemisphereo %e$orestation: less photosynthesis and release o$ stored carbon

dio(ide in plants ethane: rice paddy culti ation and digesti e processes o$ ruminants li#e

cattle )ther trace gases: nitrus o(ide and chloro$luorocarbons

,ositi e $eedbac# mechanisms +arbon dio(ide ' higher temperature ' more e aporation ' more water

apour in air ' higher temperature


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o Eg. ale in aldi es: 3F o$ island will be inundated by 1m increasein sea le el because it is only 1m abo e it

o 6ile %elta: $looding o$ $armland - I= b o$ damage to &le(andria interms o$ tourist re enue" crops etc.

&gricultural producti ityo 7ncrease in temperate regions which are wealthier due to increase in

precipitation ' longer growing season but decrease in poorer regions leads to greater disparity between north and south

o !ea water creeps in ' salini*ation ' inundated $armland Ecosystem

o ,lant migration" coral bleaching ' a$$ects $ood chain and habitat o$marine creatures

o ,roblem is the rate o$ change too rapid and huge $or organisms toadapt

7ndustrieso 9reshwater $or steam 5 cooling $or re$inery a$$ected as seawater crept

upstreamo 9orestry industry: need rKd to in ent heat and drought-resistant cropso Trans-&las#a pipeline to ?! may be damaged as perma$rost melts

ore e(treme weather conditions happening more $re/uently: heat wa e"droughts

Dyoto treaty ,lant trees 5 change agricultural practices Earn 5 buy carbon credits

18. El 6ino

El 6ino !outhern )scillation 2E6!)4: seesaw pattern o$ atmospheric pressurebetween eastern and western paci$ic

al#er circulation normally


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al#er circulation during El 6ino re erse 9low $rom western ,aci$ic to eastern ,aci$ic: Del in wa es wea#en the

in$luence o$ trade winds

,rediction )nce e ery years" but becoming less predictable due to global warming Eg. usually 1 months but 1AA8 E6!) reached pea# in early 1AA "

wea#ened suddenly in mid 1AA " and intensi$ied in 6o 1AA

7mpacts Economic impact on ,eru and Ecuador

o 6o upwelling o$ cold water ' nutrients lost ' $ish population decimated' sea birds dont $re/uent ' cannot har est guano as $ertili*er

o &bundance o$ rain inland supports pastures and cotton $ields 1A - = El 6ino

o !e ere $looding in western ,aci$ic: =38cm o$ precipitation when theynormally get 18-1=cm per year

o E(treme storms in ?! 1AAC El 6ino

o !e ere droughts in 7ndonesia" but aggra ated by de$orestationo E(treme storms in ?! and

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