global environment week three

global energy movement

transfer surplus heat fro equator to colder regions (higher latitudes) so areas don’t continue to be continuously hotter/colder, driven by density

pressure-driven air movement

molecules collide with neighbors building pressure, compressed by air above and air below fighting back, fluid (gas/liquid) will try to move to lower pressure places (up)

pressure driven air movement in columns

if column of air is warmed, it will expand (vertically) and become less dense, building pressure if contained, air will transfer to less dense column and as it empties pulls air from that column —> direct circulation and wind

landform driven air movement

features in landscape like mountains, air is forced up, decreases in pressure, molecules expand taking more volume, makes air cold (snow on mountains)

rotation driven air movement

planet rotates, movements that would be straight curve with planet (coriolis effect)

evaporation and condensation

evaporation needs energy (faster when warm), condensation releases energy (depends on how much vapor is in air, more molecules bumping back into liquid) , both happen at same time, if they are equal that is saturation

warm air has higher saturation point, takes more vapor for condensation to catch up to evaporation, opposite for cold

subsaturated is <100% evaporation wins, supersaturated is >100% condensation wins, temp where it hits 100% is dew point

cloud formation

condensation needs something to grab onto, like dust seal salt, bacteria

on the ground is dew, in air is fog, over 15m is clouds

clouds form where warm air rises because rising air cools

hadley cells

convection cell of air movement starting at equator to 30N and 30S, clouds and rain form where air rises according to these

polar cell

cell of air movement beginning at 60N and 60S going to poles, even though 60 is colder than equator, still enough difference of temp to drive circulation

ferrel cell

rises at 60 and falls at 30, moves in opposite direction and driven by movement of other cells (its weaker)

dominant surface winds

movement of air thorugh global circulation and corioilis effect make patterns of wind, in response to temp differences and pressure too, all moving air

ocean currents

water absorbs solar energy and exchanges heat with air above, water trasnfer heat energy across planet

surface currents

driven by surface winds, from east to west near equator, west to east at higher latitudes — landforms in teh way trap currents into circular circulation called gyres

deep ocean currents

is independent of surface current circulation, but by density differences (cold is dense, salinity is dense)

salinity results from minerals from land and maintained by rain and evaporation, less energy in high latitudes make cold conditions (ice) and salt is exluded from ice so it increases salinity (more dense, sink) — poles are main drivers of deep ocean (thermohaline) circulation

heat energy is from solar radiation, re-emitted radiation, and surface currents

heat map

data visualization to represent magnitude, density, or concentration

jet stream

area of fast air movement in upper atmosphere, comes from convection cells and coriolis effect moving east to west

specific heat capacity

energy required to change temp of 1 kg by 1 degree C, bigger capacity = longer time

weather

day to day changes in atmosphere

climate

long term average of weather, determines predictability of temp/precipitation, what defines extreme/expected, will change over long geological age of planet (snow ball)

climate drivers

factors shown to influence climate, can be global and regional

climate forcing

factors shown to influence climate change, primarily man made

global climate

determined by energy revied from solar and longwave radiation, or atmospheric winds (temp) and precipitation, varies spatially and temporally

temporal variability

earth axis changes how much radiation gets to each place, makes seasons

seasonal temp differences are larget at high latitudes, since solar radiation drives air circulation and movement of heat and water vapor, both temp and precipition vary seasonally

climate oscillations

type of temporal variability that swings back and forth between two phases, not just annually

ENSO

positive feedback loop near equator in pacific ocean, driver of climate oscillations.

winds pile warm water west, when winds change water sloshes back as underwater waves, waves arrive late to reverse, system overshoots and flips to other phase

causing short-term changes in global temp that can add or hide other climate forcings like GHGs

we can track by ocean surface temps

components of inso

westward suface winds → westward ocean current → westward position of warmer water → eastward convection cell

normal patterns (ENSO)

winds blow west across pacific on equator → push warm surface water west, warm water piles up near australia → cold deep water comes up near south america to replace is (upwelling) → warm water in west heats the air, warm air rises (convection cell) → air flows back east up high, sinks, blows west again along surface which keeps winds going

el nino pattern

weakens normal pattern

winds weaken → current weakens → convection cell weakens/shifts to middle of ocean→ warm water moves east to middle of ocean → winds weaken more

causes les upwelling near south america, floods in south america, weak monsoons, warmer winters, southern US storms, leaves fewer nutrients and fish decline

la nina pattern

(strengthens normal patterns)

winds strengthen → currents strengthen → convection cell strenghtens → warm water piles further west causing more upwelling to replace → winds strengthen more

causes more nutrients, more fish, strong monsoons, coast storms/hurricanes

spatial variability

solar radiation is most impactful climate forcing, but not only one (ocean currents, urban heat island effect, buffering effect of water, orography, plants (flying rivers/cloud seeding))

ocean currents

surface ocean currents bring heat in water from equator, gulf stream widely studied

gulf stream

surface currents begin at equator, deflected by north american and pushed northwards along eastern coast of north america, to northwest of europe, responsible for warmer temps in europe than should be possible given latitude

buffering effect of water

horse shoe heat map shape for differing season patterns in temperature because water bodies resist heat change

high heat capacity and ability to mix mass vertically, can hold more energy as heat than land, takes longer to lose heat

when air demp decreases, land loses heat quickly, water less, coastal area benefits from extended period of heat loss by staying warmer in winter, cooler in summer

buffering affect of wind

winds are from west, west-coast cities benefit more from buffering effect of ocean than east-coast

temperature contrasts —> precipiation contrasts

temp contrasts drive air movement and rain\long term enso, yearly monsoons (hotter land air flows in, rain, winter land cooler, out, dry) daily see breeze

orography/rain shadows

air flowing over mountain, high relief forces ari upward, air cools, loses moisture to condensate and precipitates as it cools, side of high relief faces surface winds and high precipitation, other side warm and dry bc water vapor lost to condensation on other side

urban heat island effect

low albedo of man made surfaces absorbs more solar radiation than natural surfaces (lack of veg doesn’t promote evaporative cooling) —> warmer surface warms more air —> cities are warmer

flying river

aerial river

water vapor from plant transpiration carried by wind over long distances

plants/bacteria also release particles that act as condensation nuclei to seed clouds, when enough in one spot can mote water like a river

brings rain to interior of continents, deforestation weakens it

global hydrological cycle

closed, all earth’s water formed in space and came on comets, none has come none has left, closed within planet

71% of earths surface is covered in water, most in ocean reservoir, small bit in glaciers, less than 1% for biological life

includes atmosphere, terrestrial water (subdivided), and oceans

with many linkages

precipitation

condensation under gravitational pull, falls to earth from formation in atmosphere (only large drops)

transpiration

converstion of liquid to vapor by plants, evaporation through biological linkage - major movers of freshwater in terrestrial ecosystems

flying river

cloud seeding

plants release chemical to seed formation, can produce clouds and precipitation by emitting compounds to get drops

sublimation

water molecules from solid to vapor state with no liquid between

desublimation/deposition

water from vapor to solid, no liquid state (dry ice)

runoff

water falls on land as rainfall must drain into ocean reservoir, some spend time in water reservoir on land but some move quickly back to oean through direct or river

78% of rainfall is over oceans, other falls on land and drains into oceans or long term reservoirs

residence time for water reservoirs

helps understand hydro cycle dynamics, and how humans interfere, cycle is 11 days in atmosphere

we need flying rivers to ensure freshwater gets to intererior continents

groundwater can be short or long time, we may be taking faster than natural cycle which is when water supply depletes (lake about 100 years)

forming terrestrial landscapes

tectonic plates forming new rock/recycling old into mantle

erosion → mountains flattening, water moving thorugh landscape (rivers move), shaping coasts

glacial system landforms, slowest moving rivers (snow on top of mountains never melt, condense into solid ice and weigh down till elevation is low enough to melt → carves out mountain to u-shape valley)

nutrient transfer

plant nutrients transported to and through soil by rainfall, drives chemical weathering and transport for feeding terrestrial ecosystems, the systems have been moved to stable or unstable states that make loss of soil nutrients

biomes

place shaped by how much precipitation freshwater available

life

first evolved in water, necessary for chemical reactions essential to eraly life

very little global water on land but huge impact

vapor pressure

more vapor in air = higher vapor pressure = higher condensation rate

when equal to evaporation rate, thats saturation