Soil Science Exam 2
The average translational kinetic energy of molecules, the so-called "kinetic
What is temperature?
temperature"
What happens to particles as temperature Particles speed up, moving more and occupying more space
increases?
Indirect way to measure temperature? Thermal expansion and contraction of material, i.e liquid mercury
What is heat? Transfer of kinetic energy
Object with more kinetic energy gives the object with less kinetic energy its
What is heat transfer?
momentum
- Transfers heat via molecular collision
- Requires a temperature difference across a medium
Conduction Transfers
- Area of greater kinetic energy will transfer thermal energy to an area with l
kinetic energy
- Transfers heat between two bodies by currents of moving gas or fluid
- Requires a temperature difference across a medium
Convection Transfers
- Fluid above a hot surface expands, becomes less dense, and rises, carrying
away thermal energy.
- Transfer of heat through space by electromagnetic radiation
Radiation Transfers - Can occur across a vacuum
- Waves carry energy away from the emitting object due to random motion
, Soil Science Exam 2
How does temperature influence Higher temperatures increase the rate of diffusion.
diffusion?
Soil respiration generally increases with temperature up to an optimal range
Influence of Temperature on Microbial
which rates decline as high temperatures stress and damage microbial enzym
Processes- Respiration
and activity
As temperature rises, reaction rate increases due to more frequent and force
Influence of Temperature on Microbial
collisions between enzymes and substrates. Beyond an optimal temperature
Processes- Enzyme Activation
enzymes will denature, lose their structure, and become inactive
Influence of Temperature on Microbial Rate of breakdown increases with warmth up to an optimal range. Beyond th
Processes- Organic Matter range, higher temperatures can become lethal to most microorganisms, halt
Decomposition the process
1. The net amount of energy the soil absorbs
How does soil temperature relate to
2. The energy required to change the temperature
energy?
3. The energy required for processes such as evaporation
What % of solar energy reaches the Only 10% of the energy that makes it to the surface is used to warm the soil
surface?
The fraction of light that a surface reflects. Albedo of Earth's surface determ
What is albedo?
how much incoming solar energy, or light, it immediately reflected back to sp
If all of the light that reaches the surface Equal to 1
is reflected, the Albedo is......
, Soil Science Exam 2
If 30% of the light that reaches the Equal to 0.3
surface is reflected, the Albedo is......
Dark-colored rough surfaces have a lower albedo than light-colored and sm
What soil surfaces experience more surfaces.
albedo? Dry bare soil has the highest Albedo, while saturated soil with high vegetatio
the least.
What is slope angle and aspect? The angle at which the solar radiation strikes surfaces
The amount of energy required to raise the temperature of material by 1 deg
celcius
What is Specific Heat?
ex. Pure water = 4.18 Jg and Dry soil = 0.8 Jg
4.18/0.8 = 5.22x
C = (c1m1 + c2m2) / (m1 + m2)
c1 = Specific heat of H2O (1.0 cal g-1)
c2 = Specific heat of soil (given heat capacity, cal g-1)
Equation for specific heat
m1 = Mass of H2O (% given in decimals, g)
m2 = Mass of soil (1.0 g)
Should result in cal g-1
Evaporation is a cooling process, and it takes energy to heat the water, chan
What is heat of vaporization?
it from a liquid to a vapor.
The average translational kinetic energy of molecules, the so-called "kinetic
What is temperature?
temperature"
What happens to particles as temperature Particles speed up, moving more and occupying more space
increases?
Indirect way to measure temperature? Thermal expansion and contraction of material, i.e liquid mercury
What is heat? Transfer of kinetic energy
Object with more kinetic energy gives the object with less kinetic energy its
What is heat transfer?
momentum
- Transfers heat via molecular collision
- Requires a temperature difference across a medium
Conduction Transfers
- Area of greater kinetic energy will transfer thermal energy to an area with l
kinetic energy
- Transfers heat between two bodies by currents of moving gas or fluid
- Requires a temperature difference across a medium
Convection Transfers
- Fluid above a hot surface expands, becomes less dense, and rises, carrying
away thermal energy.
- Transfer of heat through space by electromagnetic radiation
Radiation Transfers - Can occur across a vacuum
- Waves carry energy away from the emitting object due to random motion
, Soil Science Exam 2
How does temperature influence Higher temperatures increase the rate of diffusion.
diffusion?
Soil respiration generally increases with temperature up to an optimal range
Influence of Temperature on Microbial
which rates decline as high temperatures stress and damage microbial enzym
Processes- Respiration
and activity
As temperature rises, reaction rate increases due to more frequent and force
Influence of Temperature on Microbial
collisions between enzymes and substrates. Beyond an optimal temperature
Processes- Enzyme Activation
enzymes will denature, lose their structure, and become inactive
Influence of Temperature on Microbial Rate of breakdown increases with warmth up to an optimal range. Beyond th
Processes- Organic Matter range, higher temperatures can become lethal to most microorganisms, halt
Decomposition the process
1. The net amount of energy the soil absorbs
How does soil temperature relate to
2. The energy required to change the temperature
energy?
3. The energy required for processes such as evaporation
What % of solar energy reaches the Only 10% of the energy that makes it to the surface is used to warm the soil
surface?
The fraction of light that a surface reflects. Albedo of Earth's surface determ
What is albedo?
how much incoming solar energy, or light, it immediately reflected back to sp
If all of the light that reaches the surface Equal to 1
is reflected, the Albedo is......
, Soil Science Exam 2
If 30% of the light that reaches the Equal to 0.3
surface is reflected, the Albedo is......
Dark-colored rough surfaces have a lower albedo than light-colored and sm
What soil surfaces experience more surfaces.
albedo? Dry bare soil has the highest Albedo, while saturated soil with high vegetatio
the least.
What is slope angle and aspect? The angle at which the solar radiation strikes surfaces
The amount of energy required to raise the temperature of material by 1 deg
celcius
What is Specific Heat?
ex. Pure water = 4.18 Jg and Dry soil = 0.8 Jg
4.18/0.8 = 5.22x
C = (c1m1 + c2m2) / (m1 + m2)
c1 = Specific heat of H2O (1.0 cal g-1)
c2 = Specific heat of soil (given heat capacity, cal g-1)
Equation for specific heat
m1 = Mass of H2O (% given in decimals, g)
m2 = Mass of soil (1.0 g)
Should result in cal g-1
Evaporation is a cooling process, and it takes energy to heat the water, chan
What is heat of vaporization?
it from a liquid to a vapor.
