Estimate the amount of energy gained by a layer of water as the difference between energy entering from the top of the layer and energy leaving at the bottom. Energy gained/ lost is calculated from photosynthetically active radiation (PAR, which is then converted to watts) and an estimate of kd (light attenuation coefficient) which is derived from the depth of 1 percent surface light.
watts.in(top, bot, irr, z1perc)numeric vector of estimates of energy gain
Depth of the top of the layer, in meters
Depth of the bottom of the layer, in meters
PAR in uE/s (umol / m^2 / s)
Depth of 1 percent of surface light, in meters
Ryan Batt, Luke Winslow
This rough estimate is used in the Kalman filter/ smoother for water temperature. It does not account for a variety of potentially important factors, and is made specifically for use with temp.kalman(), which uses maximum likelihood to fit a linear coefficient that converts this heat gain estimate into temperature change.
Batt, Ryan D. and Stephen R. Carpenter. 2012. Free-water lake metabolism: addressing noisy time series with a Kalman filter. Limnology and Oceanography: Methods 10: 20-30. doi: 10.4319/lom.2012.10.20
temp.kalman
metab.kalman