Chapter 2 Reading Flashcards
The surface of earth is much ___(warmer or colder) than it would be if we didn’t have an atmosphere. Why?
warmer
Because the atmosphere is mostly transparent to solar radiation and mostly opaque to terrestrial emission of radiation
_____(more/less) solar energy is absorbed at the equator compared to the poles. How does the earth system deal with this imbalance?
more
Atmosphere and ocean transport energy poleward
Luminosity=
total rate at which energy is released by the sun
Photosphere=
The region of the sun from which most of its energy emission is released to space.
Temp of the earth’s photosphere= 6000K
Where/ how is energy produced in the sun?
Energy is produced in the core of the sun by nuclear fusion: lighter elements are made into heavier ones, releasing energy in the process
It’s predicted that the luminosity of the sun has increased 30% during earth’s lifetime (4.5billion years). What’s the cause?
gradual increase in the density of the sun as lighter elements convert to heavier ones (=increased energy output)
The planets orbit around the sun in ellipses, which have 3 characteristics:
- mean planet-sun distance
- eccentricity
- orientation of the orbital plane
The mean distance from the sun controls the amount of ____ ____ arriving at the planet. It also controls the length of a ____ for that planet
solar irradiance
= energy delivered per unit time per unit area
year
= the time it takes the planet to complete one orbit
The planetary year ___ with increasing distance from the sun
increases
Eccentricity=
the measure of how much an orbit deviates from being perfectly circular
- controls the amount of variation of energy throughout the year
A planet’s rotation ___ controls the daily variation of insolation at a point
rate (how fast it spins)
Obliquity=
(tilt)
the angle that the axis of rotation is at
Longitude of Perihelion=
measures the phase of the seasons relative to the planet’s position in the orbit
eg. earth passes closest to the sun (perihelion) during summer in S hemisphere
What is the first law of thermodynamics for a closed system?
the heat added to a system is equal to the change in internal energy plus the work extracted
Heat can be transported to and from a system by:
1
2
3
- Radiation: no mass is exchanged, no medium required.
- Conduction: no mass is exchanged, a medium transfers heat by collisions
- Convection: mass is exchanged. Net movement of mass may occur, but usually parcels with different energies change places (energy exchange with no net movement of mass)
