Thomas: Thomas algorithm for solving simultanious heat fluxes
In ilyamaclean/microclimc: Below or above canopy microclimate modelling with R
Thomas R Documentation
Thomas algorithm for solving simultanious heat fluxes
Description
Thomas implements the Thomas algorithm for solving simultanious heat
fluxes between soil / air layers.
Usage
Thomas(tc, tmsoil, tair, k, cd, f = 0.6, X = 0)
Arguments
tc
vector of soil and air temperatures (deg C) from previous timestep (see details)
tmsoil
temperature (deg C) of deepest soil layer. Typically mean annual temperature
tair
air temperature at reference height 2 m above canopy in current time step (deg C)
k
vector of thermal conductances between layers (W / m^2 / K) (see details)
cd
thermal heat capacity of layers (J / m^3 / K)
f
forward / backward weighting of algorithm (see details)
X
vector of temperatures to be added resulting from e.g. leaf heat fluxes or radiation
absorbed by top soil layer
Details
The vector tc must be ordered with reference air temperature first and the soil temperature
of the deepest layer last. I.e. the length of the vector tc is the number of nodes + 2.
The vector k is the conductivity between each node and that diectly below it, the first value
representing conductivity between reference height and the top canopy node. I.e. the length
of the vector k is the number of nodes + 1. The vector cd is the heat storage at each node.
I.e. the length of the vector cd is the same as the number of nodes. The weighting factor f may
range from 0 to 1. If f = 0, the flux is determined by the temperature difference at the beginning
of the time step. If f = 0.5, the average of the old and new temperatures is used to compute heat flux.
If f = 1, fluxes are computed using only the new temperatures. The best value to use
for f is determined by considerations of numerical stability and accuracy and experimentation
may be required. If f = 0 more heat transfer between nodes is predicted than would actually
occur, and can therefore become unstable if time steps are too large. When f > 0.5,
stable solutions will always be obtained, but heat flux will be underestimated. The
best accuracy is obtained with f around 0.4, while best stability is at f = 1.
A typical compromise is f = 0.6.
Value
a vector of temperatures (deg C) for each soil / air layer for current time step. The first value
is tair and the last tmsoil
ilyamaclean/microclimc documentation built on July 28, 2023, 1:40 a.m.
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| Thomas | R Documentation |
Thomas algorithm for solving simultanious heat fluxes
Description
Thomas implements the Thomas algorithm for solving simultanious heat
fluxes between soil / air layers.
Usage
Thomas(tc, tmsoil, tair, k, cd, f = 0.6, X = 0)
Arguments
tc |
vector of soil and air temperatures (deg C) from previous timestep (see details) |
tmsoil |
temperature (deg C) of deepest soil layer. Typically mean annual temperature |
tair |
air temperature at reference height 2 m above canopy in current time step (deg C) |
k |
vector of thermal conductances between layers (W / m^2 / K) (see details) |
cd |
thermal heat capacity of layers (J / m^3 / K) |
f |
forward / backward weighting of algorithm (see details) |
X |
vector of temperatures to be added resulting from e.g. leaf heat fluxes or radiation absorbed by top soil layer |
Details
The vector tc must be ordered with reference air temperature first and the soil temperature
of the deepest layer last. I.e. the length of the vector tc is the number of nodes + 2.
The vector k is the conductivity between each node and that diectly below it, the first value
representing conductivity between reference height and the top canopy node. I.e. the length
of the vector k is the number of nodes + 1. The vector cd is the heat storage at each node.
I.e. the length of the vector cd is the same as the number of nodes. The weighting factor f may
range from 0 to 1. If f = 0, the flux is determined by the temperature difference at the beginning
of the time step. If f = 0.5, the average of the old and new temperatures is used to compute heat flux.
If f = 1, fluxes are computed using only the new temperatures. The best value to use
for f is determined by considerations of numerical stability and accuracy and experimentation
may be required. If f = 0 more heat transfer between nodes is predicted than would actually
occur, and can therefore become unstable if time steps are too large. When f > 0.5,
stable solutions will always be obtained, but heat flux will be underestimated. The
best accuracy is obtained with f around 0.4, while best stability is at f = 1.
A typical compromise is f = 0.6.
Value
a vector of temperatures (deg C) for each soil / air layer for current time step. The first value
is tair and the last tmsoil
R Package Documentation
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We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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