Notes on all lectures "Natural Processes (GEO1-2412 )"

Lectures Natural Processes
Inhoudsopgave
Lecture 1 - 16/11/2022 – Energy in the atmosphere.......................................................................................2

Lecture 2 – 16/11/2022 –Energy and circulation.............................................................................................7

Lecture 3 - Moisture in the atmosphere........................................................................................................ 12

Lecture 4 – 23/11/2022 – Air pollution......................................................................................................... 13

Lecture 5 – 30/11/2022 - River basin hydrology............................................................................................ 17

Lecture 5 – principles of groundwater flow – 05/12/2022.............................................................................26

Lecture 6...................................................................................................................................................... 29

Q&A............................................................................................................................................................ 30

Lecture 7 - Species interactions and community dynamics............................................................................33

Lecture 8 – biodiversity theories.................................................................................................................. 34

Lecture 9 – introduction to soil science......................................................................................................... 36

,Lecture 1 - 16/11/2022 – Energy in the atmosphere

Earths atmosphere
 Trophoshere
o Contains 90% of mass because
gravity pulls down most of the
molecules
o Weather occurs in this part
 Stratosphere
o Contains ozone which protects us (but
if ozone would be in the troposphere,
it would be bad for us)
o Temperature decreases with height
 Mesosphere
 Thermosphere
 Exosphere


Atmospheric composition
 N2: 78%
 O2: 21%
 Ar: 1%
 Rest is trace gasses: gasses with a very low percentage that still influence the
greenhouse effect

Forms of energy (ultimately every form converts into heat)
 Kinetic: energy from motion
 Potential: energy of potential falling energy
 Heat
 Chemical: energy stored in molecules
 Radiation
o Different types
o Higher wave length = lower energy

Black body radiation: All objects emit radiation (exept at 0*K). black bodies emit radiation
in a range of wavelengths according to Planck’s curve

 Wien’s law:
 The position of the peak depends on the temperature




Stefan Boltzmann law for the area under the graph
 Total emitted energy increases with temperature ( to the fourth power)

o e = emissivity = 1 for black body radiation

, o s = a given constant

short wave & longwave radiation
 sun emits at shorter wavelengths then the earth
 if the temperature is higher it will have a peak at a lower wave length
o sun is hotter so it will have a shorter wave length
o earth is cooler so it will have a lowe wave length

earth emits radiation and the clouds/atmosphere emits radiation




Shortwave radiation
 reflection
o 20% reflects off the clouds to the
atmosphere
o 4% reflects from earths surface
to the atmosthere
 Scattering
o 6% of the particals scatter the
radiation back to the atmosphere
 Absorbtion
o 51% is absorbed by the earths
surface
o 19% is absorbed by the
atmosphere and clouds
 Re-emission
Albedo effect: property of reflecting, the whiter
an object, the more it reflects, the higher the
albedo


Energy fluxes (51% and 19% of absorbed radiation)
 The earth Loses radiation through longwave radiation (red squiggly lines) by:
o Infrared (-117)

, o Evaporation = latent heat (-23)
o Convection and conduction = sensible heat (-7)
 The atmosphere loses radiation by
o Infrared to space (-64)
o Infrared to earth (-96)
 Balance between energy lost and energy gained is because the earth and the
atmosphere do not gain or lose temperature
o The slight difference that occurs causes global warming
 Red is combined
 Blue is earth
 Green is atmosphere




Spatial variability in absorbed shortwave radiation
 Most absorption over tropical areas because the angle of the radiation is
perpendicular to the earth’s axis of rotation = more radiation per square meter
 More absorption over oceans then over land because of the albedo effect




Net radiation
 red: incoming > outgoing
 Blue: outgoing > incoming
 Tropics heating up and poles cooling down
 Air and water redistribute heat