Acidification induced mortality
In addition to the other effects of acidification a specific extra mortality term due to ocean acidification has been added. This uses a logistic curve which begins when pH drops below pHmortstart_FXX. The shape of the curve is given by:
mPH = pHmortA / (1.0 + exp(- pHmortB * ( pHmortmid - currentPH)))
where
pHmortA is the maximum acidification induced mortality rate
pHmortB is the steepness of the curve
pHmortmid is the pH of the mid point of the curve
This new functionality requires pHmortstart_FXX, pHmortA_FXX, pHmortB_FXX, pHmortmid_FXX to be added for each functional group (FXX) in biol.prm