chapter 3 solar energy and seasons Flashcards
urban heat island
cities heat up as they absorb sunlight and retain heat
temperature
the average speed of molecular movement within a substance or an object
heat
the energy transferred between materials or systems due to their temperature differences
three ways heat moves:
conduction- the process by which energy is transferred through a substance or between objects in direct contact
convection- the transfer of heat through movement of mass within a fluid
radiation- the process by which wave energy travels through the vacuum of space or through a physical medium
advection
the horizontal movement of some property of the atmosphere, such as heat
radiant energy
energy that is propagated in the form of electromagnetic waves
electromagnetic spectrum
the full range of wavelengths of radiant energy
wiens law
objects with higher temperatures emit more photons at shorter wavelengths than objects with lower temperatures
stefan-boltzmann law
objects with higher temperatures emit photons at higher rates than objects with lower temperatures
longwave vs shortwave radiation
long- electromagnetic radiation greater than 4 micrometers ex. earth radiation
short- less than 4 micrometers ex. sun radiation
UV radiation is divided into __ categories based on ___
3 (UV-A, UV-B, UV-C)
wavelength
visible light
the portion of the electromagnetic spectrum which we can see
infrared radiation
has wavelengths longer than visible light between .75 and 1 000 micrometers
thermal infrared
wavelengths that are longer than near infrared, we can feel it as warmth and measure it with a thermometer
insolation (incoming solar radiation)
fraction of the suns energy that the earth intercepts. is transmitted, scattered, reflected and absorbed as it encounters earth
transmission
the unimpeded movement of electromagnetic energy through a medium such as air water or glass
scattering
the redirection of SWR in random directions after it strikes an object
albedo
the reflectivity of a surface, shown as a percentage
earths albedo is 31%
radiative equilibrium temperature
temperature of an object resulting from the balance between incoming and outgoing energy
the greenhouse effect
process by which the atmosphere is warmed as greenhouse gases and clouds absorb and counterradiate heat
global heat engine
the movement of heat from low to high latitudes and low to high altitudes as a result of heating inequalities across earths surface
astronomical unit (AU)
the average distance between earth and sun
seasons are caused by _____, not by ____.
the tilt of the earths axis
the changing distance between earth and the sun
plane of the ecliptic
the flat plane that the orbital paths of the planets trace
Earth is closer to the sun in ___ (perihelion) than it is in ___ (aphelion).
january
july
subsolar point
the single point at which the suns rays are perpendicular to earths surface at or near noon
circle of illumination
the line separating night from day where sunrise and sunset occur
solstices
december- subsolar point at the tropic of capricorn
june- subsolar point at the tropic of cancer
equinoxes
march- subsolar point crosses the equator
september- subsolar point crosses the equator
on this day there is 12 hours of day and night everywhere
continental effect
increase in seasonality with distance from the oceans
continental effect is based on 4 factors of the water:
- specific heat
- evaporation
- mixing of water
- transparency
specific heat
heat required to raise temperature of any object or material by a given amount
it takes 1 calorie of energy to heat 1 gram of water 1 degree C
prevailing winds
generally from the west, so west coasts have maritime climates and east coasts have continental climates
renewable energy
energy that comes from sources are nor depleted when used
photovoltaic cells
semiconductor that converts sunlight to electricity
