spinup: Model spin-up for first time-step

In ilyamaclean/microclimc: Below or above canopy microclimate modelling with R

Model spin-up for first time-step

Description

spinup runs the model repeatedly using data form the first time-step for a set number of steps to ensure initial conditions are stable and appropriate soil temperatures are set.

Usage

spinup(
  climdata,
  vegp,
  soilp,
  lat,
  long,
  edgedist = 100,
  reqhgt = NA,
  sdepth = 2,
  zu = 2,
  theta = 0.3,
  thetap = 0.3,
  merid = 0,
  dst = 0,
  n = 0.6,
  plotout = TRUE,
  steps = 200,
  metopen = TRUE,
  windhgt = 2,
  zlafact = 1,
  surfwet = 1
)

Arguments

climdata	a data.frame of climate variables needed to run the run the model (dataset should follow format of weather())
vegp	a list of vegetation parameters as returned by microctools::habitatvars()
soilp	a list of soil parameters as returned by soilinit()
lat	Latitude (decimal degrees)
long	Longitude (decimal degrees, negative west of Greenwich meridion)
edgedist	distance to open ground (m)
reqhgt	optional height for which temperature is required (see details)
sdepth	depth of deepest soil node (m)
zu	height above ground of reference climate measurements (m)
theta	volumetric water content of upper most soil layer in current time step (m^3 / m^3)
thetap	volumetric water content of upper most soil layer in previous time step (m^3 / m^3)
merid	an optional numeric value representing the longitude (decimal degrees) of the local time zone meridian (0 for GMT).
dst	an optional numeric value representing the time difference from the timezone meridian (hours, e.g. +1 for BST if merid = 0).
n	forward / backward weighting for Thomas algorithm (see Thomas())
plotout	optional logical indicating whether to a plot a profile of temperatures upon completion.
steps	number of iterations for which which to run spin-up
metopen	optional logical indicating whether the wind measurement used as an input to the model is from a nearby weather station located in open ground (TRUE) or above the canopy for which temperatures are modelled (FALSE - see details)
windhgt	height above ground of wind measurement. If metopen is FALSE, must be above canopy.
zlafact	numeric value indicating how close to leaves air temperatures are needed for (1 - average leaf-air distance, 0.5 = half average leaf-air distance etc.). Must be greater than 1.
surfwet	fraction of vegetation surface acting like a free-water surface

Details

If reqhgt is set, and below the height of the canopy, the canopy node nearest to that height is set at the value specified. The returned value tabove is then the temperature at the top of the canopy. If reqhgt is above canopy, nodes are calculated automatically, but tabove is the temperature at height reqhgt. If temperatures below ground are needed, the depth can be set using soilinit()

Value

a list of model outputs as for paraminit() or runonestep()

Examples

tme<-as.POSIXlt(weather$obs_time, format = "%Y-%m-%d %H:%M", tz = "UTC")
vegp <- habitatvars(4, 50, -5, tme, m = 20)
soilp<- soilinit("Loam")
# run spinup and produce profile plot
modelout<-spinup(weather, vegp, soilp, lat = 50, long = -5)

ilyamaclean/microclimc documentation built on July 28, 2023, 1:40 a.m.