Transcript Soil thermal regime - Soil Physics, Iowa State University

Outline
• Announcements
• Soil Thermal Regime
• Ice (courtesy of Yuki & Ranae)
Soil Physics 2010
Announcements
• Homework 6 due Friday
(I recommend the linear/Moldrup relationship in #3)
• No more typos?
• Eric’s presentation posted
• Review sessions next week
(fake)
Soil Physics 2010
Quiz!
Quiz, question 1:
A 2nd-order partial differential equation has appeared in various
forms in recent lectures. Only a few variables, and the
proportionality coefficient, differ from one form to another. Write
one form of this equation as we have used it.
   
 



D



t
z 
z 
Hydraulic diffusion
Thermal diffusion
(heat flow)
Soil Physics 2010
C
C
 D 2
t
z
2
Molecular diffusion
T
T
  DT 2
t
z
2
Quiz, question 2:
Gradient of
What?
Darcy’s Law
Fick’s Law
Fourier’s Law
Extra credit:
Ohm’s Law
Soil Physics 2010
What Moves?
Name of the
Proportionality
Coefficient
What is Conserved
(Transient Form)?
Quiz, question 2:
Gradient of
What?
Darcy’s Law
Fick’s Law
Fourier’s Law
Extra credit:
Ohm’s Law
Soil Physics 2010
Water
Potential
Concentration
Temperature
Electrical
Potential
T
 2T
  DT 2
t
z
What Moves?
Name of the
Proportionality
Coefficient
What is Conserved
(Transient Form)?
Quiz, question 2:
Gradient of
What?
Darcy’s Law
Fick’s Law
Fourier’s Law
Extra credit:
Ohm’s Law
Soil Physics 2010
T
 2T
  DT 2
t
z
What Moves?
Water
Potential
Water
Concentration
Molecules
Temperature
Heat
Electrical
Potential
Current
(electrons)
Name of the
Proportionality
Coefficient
What is Conserved
(Transient Form)?
Quiz, question 2:
Gradient of
What?
Darcy’s Law
Fick’s Law
Fourier’s Law
Extra credit:
Ohm’s Law
Soil Physics 2010
Water
Potential
T
 2T
  DT 2
t
z
What Moves?
Name of the
Proportionality
Coefficient
Water
Hydraulic
Conductivity
Molecules
Molecular
Diffusivity
Temperature
Heat
Thermal
Diffusivity
Electrical
Potential
Current
(electrons)
Electrical
Conductivity
Concentration
(or diffusivity)
What is Conserved
(Transient Form)?
Quiz, question 2:
Name of the
Proportionality
Coefficient
What is Conserved
(Transient Form)?
Water
Hydraulic
Conductivity
Water
(volume)
Molecules
Molecular
Diffusivity
Mass
(molecules)
Temperature
Heat
Thermal
Diffusivity
Energy
(heat)
Electrical
Potential
Current
(electrons)
Electrical
Conductivity
Charge
(electrons)
Gradient of
What?
Darcy’s Law
Fick’s Law
Fourier’s Law
Extra credit:
Ohm’s Law
Soil Physics 2010
T
 2T
  DT 2
t
z
Water
Potential
Concentration
What Moves?
Summary
Gradient of
What?
Name of the
Proportionality
Coefficient
What is Conserved
(Transient Form)?
Water
Hydraulic
Conductivity
Water
(volume)
Molecules
Molecular
Diffusivity
Mass
(molecules)
Energy
(heat)
Charge
(electrons)
What Moves?
Darcy’s Law
Water
Potential
Fick’s Law
Concentration
Fourier’s Law
Temperature
Heat
Thermal
Diffusivity
Electrical
Potential
Current
(electrons)
Electrical
Conductivity
Ohm’s Law
The stuff that moves is conserved
The gradient is about how
“strong” or “active” that stuff is
Soil Physics 2010
Soil thermal regime
Steady-state
T
qh  
z
Transient
T
T
  DT 2
t
z
(Like
Darcy’s Law)
2
Instantaneous change
(like infiltration)
This is how we
usually study soil
New! Improved! Dynamic! thermal regimes.
Cyclical change
Soil Physics 2010
A particular part of the soil thermal regime:
Ice
by Yuki & Ranae
Soil Physics 2010