Lecture 3 Flashcards
Cycles
- trace the flow of material and or energy through systems
- show both reservoirs and processes
What is a cycle called when it is quantified?
- a budget
What are the energy inputs of the energy cycle?
- solar radiation
- geothermal energy (released from nuclear decay of uranium and thorium) through convection and conduction
- tidal energy
What are the energy loses of the energy cycle?
- reflection into space
- re-radiation as radiant heat
The hydrologic cycle: Budget
- atmosphere 0.013x10^15 meters cubed
- ocean 1359x10^15 meters cubed
- land 33.6x10^15 meters cubed (glaciers, ground water, lakes, streams, biosphere)
The hydrologic cycle: reservoirs
Oceans 97.5%
Ice sheets <2%
Groundwater <1%
Lakes, rivers, atmospheres 0.01%
Reservoir change
For most reservoirs, the rate of flow in balances the rate of flow out
Volume of water in the reservoir is approximately constant
When flow in>flow out
Reservoir expands
“Sink”
When flow out>flow in
Reservoir contracts
“Source”
The ice sheet reservoir has been getting smaller over time because
Melting>snowfall
Resident time
Size of reservoir/flow rate
A measure of HOW LONG the average water molecule spends in the reservoir
Typical residence times?
Oceans and ice caps: thousands of years
Streams and rivers: a few weeks
Atmosphere: a few days
Our solar system
Centers around a single sun
Numerous objects orbiting sun including dwarf and minor planets, comets
Satellites orbiting planets
The solar system is…
A heterogenous distribution of planets around the sun
Terrestrial planets closer in radius than Jovian planets
Sun->mercury->Venus->earth->mars->Jupiter->Saturn
->Uranus->Neptune
Terrestrial planets
Mercury
Venus
Earth
Mars
Jovian planets
Jupiter
Saturn
Uranus
Neptune
The sun as a star
Fairly average star in universe
~700 000 km radius (109x Earths)
~10^30 kg (300 000 x Earths mass)
Source of solar energy in sun
Nuclear fusion of hydrogen into helium
In core-62% helium 38% hydrogen
Sun’s energy output
- 3.8 x 10^26 W total energy output
- 1.7x10^17 W reaches Earth
- energy flux at Earth’s distance is 1370 W/meter squared
Energy flux on earth’s surface
Energy flux is reduced away from equator because the angle of incidence is shallower and energy is spread over a larger area
This is responsible for the generally warmer temeorature near the equator
Effects of orbital changes
- all of these cycles affect the distribution of solar energy over earth’s surface:
- Precision of equinoxes (wobble of axis)
- tilt of axis (changes slightly changing seasons)
- Eccentricity (high eccentricity leads to extremes)
-affect earth’s climate
Planets discovered with a telescope p?
-Uranus and Neptune and several dwarf planets
How are planets divided into two categories
Based on density and distance from sun
Terrestrial planets are classified according to
Closest to sun
Rocky crust
Denser rocky mantle
Metallic core
