(4) geo: heat transport

heat

energy transferred from a hotter system to a colder system

temperature

the average kinetic energy of all molecules in a system

latent heat

energy gained or lost when matter changes state

sensible heat

heat that can be sensed by humans

what is a great transporter of heat?

water

latent heat in the atmosphere

energy from the sun evaporates water, water condenses it, and moves it into the atmosphere

why does water take so much energy before changing phase?

hydrogen bonding

hydrogen bonding

non-covalent interactions between electronic dipoles in a water molecule

oxygen is..

more electronegative than hydrogen

oxygen attracts…

electrons from hydrogen

negative dipoles

form near oxygen

positive dipoles

form near hydrogen

how is heat transferred?

radiation, conduction, convection, and advection

radiation

energy that moves through space by vibrating electrons, how the earth loses energy to space, the source of heat transport from the sun to the earth

conduction

molecule to molecule transfer of heat energy as it diffuses through a substance

hotter atoms have more energy and move faster, when they bump into each other the energy is transferred

convection

transfer of heat by mixing of circulation

driven by density differences, very important in the atmosphere and ocean

advection

horizontal movement of heat energy

mid-latitudinal cyclones

how does EMR interact with the atmosphere and all matter?

transmission, reflection, refraction, absorption, scattering

transmission

EMR passed completely through a medium

heat passing through a car and heating it up

direct radiation

EMR that passes through the atmosphere without interacting with it, and travels through earths surface

scattering

random deflection and redirection of EMR by gas molecules and aerosols (diffuse radiation)

makes the sky blue and clouds white

diffuse radiation

EMR that has been scattered around the atmosphere and eventually travels to earth’s surface (shadows aren’t completely dark)

what would the earth look like without diffuse radiation?

the moon

why is the sky blue?

rayleigh scattering (the shortest wavelengths of light are scattered in violet and blue)

why are sunsets red?

rayleigh scattering (when sunlight enters the atmosphere at an oblique angle, longer wavelengths in red, orange, and yellow begin to scatter)

absorption

EMR that strikes an object and warms it

wearing a black shirt in hot weather

why are clouds and fog white?

mie scattering (larger molecules of water scatter all light equally)

what is a good example of EMR absorption?

ozone

high energy ultraviolet light interacts with ozone and splits it

ozone layer depletion

CFCs catalyze the destruction of ozone, common in registrants

what do CFCs and HFCs do?

break down stratospheric zones

when were CFCs banned?

1978 by the montreal protocol (U.S.)

refraction

the path of EMR changes in a different medium (straw in water)

what is an example of refraction?

sunsets appearing after the sun is beyond the horizon

reflection

the ability of an object to repel EMR (wearing light colors reflect more than darker colors)

albedo

the reflective quality of an object, difference surfaces of earth have a different one

how does the albedo of water change?

by latitude, the oblique angels reflect more sunlight

what are some patterns of global albedo?

more reflections at high altitudes by water

brighter colors = more reflection

darker colors = less reflection

is earth’s albedo changing?

yes, ice sheets are disappearing and are being replaced with darker soil

sea ice in the NH are disappearing as the artic becomes more green

aerosols

small particles that are suspended in the atmosphere

what do volcanic aerosols do?

increase albedo and cool the earth

what do black carbon aerosols do?

decrease albedo and warm the planet

how have humans altered albedos?

by having over areas that were previously forested

asphalt and buildings are darker than a forest canopy which decreased albedo

low cloud albedos

thicker / fluffier, white cloud tops, reflects off the top of the cloud, have a cooling affect

high cloud albedos

thinner / wispier, made of mostly ice, mirrors for longwave radiation, has a warming affect