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Last data update: 2014.03.03

R: Estimate net long wave heat radiation

calc.lw.net

R Documentation

Estimate net long wave heat radiation

Description

Returns the net long wave radiation based on Crawford and Duchon, 1999.

Usage

calc.lw.net(ts.data, lat, atm.press)

calc.lw.net.base(dateTime, sw, Ts, lat, atm.press, airT, RH)

Arguments

`ts.data`	Object of class `data.frame` including the required variables(see details for list of variables and their units)
`lat`	latitude in degrees north
`atm.press`	atmospheric pressure in mb
`dateTime`	vector of datetime in POSIXct format
`sw`	numeric value of short wave radiation, W/m2
`Ts`	numeric value of surface water temperature, degC
`airT`	numeric value of air temperature, degC
`RH`	numeric value of relative humidity, %

Value

## for calc.lw.net.base

A numeric value of net long wave heat flux in W/m^2

## for calc.lw.net

A data.frame with columns datetime and lwnet in W/m^2

Author(s)

R Iestyn Woolway Jordan S. Read Hilary Dugan Luke Winslow

References

Crawford, T.M., and Duchon, C.E. 1999. An improved parameterization for estimating effective atmospheric emissivity for use in calculating daytime downwelling longwave radiation. Journal of Applied Meteorology 38: 474-480.

Examples


## Base example
dateTime <- as.POSIXct("2013-12-30 23:00")
Uz <- 3
airT <- 20
RH <- 90
sw <- 800
wndZ <- 2
Kd <- 2
lat <- 54
lake.area <- 5000 
atm.press <- 1013
Ts <- 22
calc.lw.net.base(dateTime,sw,Ts,lat,atm.press,airT,RH)

## Example using timeseries in a data frame
data.path = system.file('extdata', package="LakeMetabolizer")

sp.data = load.all.data('sparkling', data.path)

# Prep the input data
ts.data	= sp.data$data #pull out just the timeseries data
atm.press	= 1018
lat	= sp.data$metadata$latitude

lwnet = calc.lw.net(ts.data, lat, atm.press)
plot(lwnet$datetime, lwnet$lwnet)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(LakeMetabolizer)
Loading required package: rLakeAnalyzer
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/LakeMetabolizer/calc.lw.net.Rd_%03d_medium.png", width=480, height=480)
> ### Name: calc.lw.net
> ### Title: Estimate net long wave heat radiation
> ### Aliases: calc.lw.net calc.lw.net.base
> ### Keywords: math methods
> 
> ### ** Examples
> 
> 
> ## Base example
> dateTime <- as.POSIXct("2013-12-30 23:00")
> Uz <- 3
> airT <- 20
> RH <- 90
> sw <- 800
> wndZ <- 2
> Kd <- 2
> lat <- 54
> lake.area <- 5000 
> atm.press <- 1013
> Ts <- 22
> calc.lw.net.base(dateTime,sw,Ts,lat,atm.press,airT,RH)
[1] -52.64892
> 
> ## Example using timeseries in a data frame
> data.path = system.file('extdata', package="LakeMetabolizer")
> 
> sp.data = load.all.data('sparkling', data.path)
> 
> # Prep the input data
> ts.data	= sp.data$data #pull out just the timeseries data
> atm.press	= 1018
> lat	= sp.data$metadata$latitude
> 
> lwnet = calc.lw.net(ts.data, lat, atm.press)
> plot(lwnet$datetime, lwnet$lwnet)
> 
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>