calc.lw.net {LakeMetabolizer}

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.

See Also

k.read and k.macIntyre

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)