Atmosphere Flashcards
atmosphere
thin layer of gases, solids, and liquids surrounding Earth
functions of the atmosphere
- absorbs radiation
- moderates climate
- transports and recycles water and nutrients
- layered by temp, density, and composition
- extends up to the moon
basic components of the atmosphere
fixed gases (O2 and N2) and other variable gases (Ar, Xe, Ne, H, He, Kr, CO2)
layers of the atmosphere
- troposphere
- stratosphere
- mesosphere
- thermosphere
- exosphere
temps of the atmosphere
changes with height and lapse rate
atmospheric pressure
applied by the weight of air molecules above the surface, highest at the surface and decreases as you go up,
atmospheric moisture
measured by water vapour content and temp, ability of air to hold moisture depends on its temp (at low temps, less moist)
relative humidity
water vapour content as a percentage of the air’s max capacity
solar energy and the atmosphere
solar energy heats Earth’s surface and atmosphere, beam focuses energy on the equator and diffuses across polar regions, some energy bounces off due to the atmosphere, ozone, and clouds, some reaches the surface and get absorbed, surface then radiates its own energy to offset the absorbed energy, this can be absorbed by GHGs, warms up the atmosphere
Greenhouse Effect
natural GHGs trap outgoing energy in the atmosphere to keep the surface warm, human augmentation is intensifying the warming
axial tilt and the atmosphere
creates the seasons and defines time, in winter, we receive less radiation due to being tilted away from the sun and more radiation in summer
imbalances in the energy budget
caused by tilt and energy distribution, results in hot and cold regions and variations in density, air will always move from areas of high to low density, heat is transported via winds and oceans to fix imbalances, heat and energy transfer mechanisms are responsible for most weather
heat/energy transfer processes
- conduction (direct transfer)
- convection (movement of hot and cold)
- radiation (transferred thru the air)
2 types of heat transfers
- sensible heat: moves energy as warm air currents sending excess heat from tropical to polar regions, can be seen
- latent heat: stored in water mols during evaporation which follows air currents and is released into colder envs, energy that changes the STATE of the material, can’t really be seen, drives most weather processes
Coriolis Effect
air currents are affected by Earth’s rotation, bends to the right in Northern Hemisphere and to left in Southern Hemisphere, air always moves from high to low pressure, leads to typical wind and storm patterns, ensures that each type of storm has an associated direction that it always follows
cyclones
low-pressure systems with rising inward spiraling air
anticyclones
high-pressure systems with sinking outward spiraling air
air pollution
comes in the form of gases, aerosols, and particulates (which can be solid, liquid or gas), originates from both natural and anthropogenic sources and be stationary or mobile
types of pollutants
- primary: emitted directly
- secondary: pollutants react with the atmosphere
natural sources
dust storms and trade winds (dust is lifted from atmosphere and transported), volcanoes (release sulfur, chlorine compounds, and ash particulates), and forest fires/wildfires (release soot, CO, and CO2); natural sources aggravated by human activity like ag and grazing (causes erosion, desertification) and fossil fuel emissions (by power plants, manufacturing, etc.)
effects of tropospheric ozone
- formed when gases react in sunlight
- warms the atmosphere
- damages plants by reducing photosynthesis and ability to sequester carbon
- leads to respiratory illnesses in humans
2 types of how pollutants reach the surface
- dry deposition: particles fall out of the atmosphere
- wet deposition: pollutants become clouds and fall to the ground as precipitation
acid rain
caused by contaminants in the air, removes nutrients from soils, kills trees, marine life is severely affected if it gets into waterbodies
Keeling curve
tracks CO2 accumulation in the atmosphere over time, pattern represents the natural oscillations of plant growth cycles, increases in fall and winter during minimal photosynthesis and decreases inn spring and summer during greater photosynthesis
GHGs
- CO2: comes from respiration, decomp, fossil fuels, deforestation
- CH4: from fossil fuels, livestock, landfills, rice cultivation
- N2O: feedlots, manufacturing, synthetic feeders
- O3: photochemical smog
- H2O: natural sources
- CFCs and HFCs: aerosols
air quality
industrial pollutant shift, ag produces airborne byproducts of pesticides and fertilizers, feedlots concentrate animal wastes, wildfires and dust storms, degrading quality leads to chronic and acute health impacts esp. respiratory problems
weather
observable and current expressions of behaviours in the atmosphere
climate
average patterns of temp, precipitation, circulation (long-term weather patterns), influences everything and naturally changes, c.c. occurs when paterns change
solar (short-wave) radiation
most is reflected but some are absorbed by the atmosphere and surface
terrestrial (long-wave) radiation
emitted by the surface, atmosphere, clouds, thermals, latent heat
history of Earth’s climate
original atmosphere was rich in H and He, replaced by effluent from volcanic eruptions, Earth cooled and H2O condensed, CO2 dissolved, SO2 was incorporated, and N2 remained
continental drift
Earth’s surface evolved thru a series of land-ocean configurations, facilitated by plate tectonics which broke the supercontinent into subcontinents, redistributed how energy affects certain parts, drift formed diff climates across the planet
events that were responsible for the cooling of the surface
- relocation of the south pole (Antarctica allowed ice and glaciers)
- creation of the Atlantic Ocean (coastlines are warmer and wetter, changes ocean currents)
- major mountain chain formation (mountains can change airflow, heat distribution, and contribute to chemical weathering of rocks)
- creation of Central America (blocks ocean currents, changing how they behave, gulfstream current distributes heat from America to E)
- separation of South America from Antarctica (opened a single current that goes around Antarctica, which allowed it to deepfreeze)
basic Earth-Sun geometry changes thru time
- obliquity: sometimes tilted more or less towards the Sun, changes intensity of seasons
- precession: north pole points in diff directions thru time, will point to diff stars, fundamentally changes seasons
- eccentricity: shape of orbit changes, sometimes closer or further from the sun
Milankovitch cycles
each cycle lines up with the amount of solar radiation received, variability in solar radiation translates into temp variability
ice ages
surface has cooled a lot due to ice ages, ice piling also led to lowering sea levels
volcanic eruptions
spew material into the atmosphere, serve as global coolants, and changes short-term climate
radiative forcing
describes the impact that specific gases and aerosols have on the global radiation budget, some have negative forcing which indicates that they lead to global cooling, natural sources of forcing take a long time while human sources accelerate radiation absorption, affected by GHG emission
GHG emissions
increased emissions increase radiative forcing and create env problems, carbon emissions are not able to decay as easily over time
main 3 fuels
- coal
- oil
- natural gas
global warming
result of increased radiative forcing, rising global temps, Arctic regions are warming up which is bad since they act as coolants, deepfreeze in Antarctica has started to melt
impacts of global warming
- ice retreat and Arctic sea ice extent is decreasing (ice helps cool Earth and provides habitats for many species)
- melting glaciers (glacial water is important as a water source)
- rising sea levels (coastal regions are vulnerable)
- disease has become more common
- extreme weather
- food and water scarcity
- displacement of ppl (due to natural disasters)
2 main categories of response to global warming
- mitigation (actions that lessen the severity of impacts)
- adaptation (accepting the impacts and adjuting actions for it, managing the risks of c.c. impacts)
