predict_pH {respirometry}

Predict pH post-respiration

Description

Predicts the pH of seawater after a defined amount of oxygen consumption.

Usage

predict_pH(
  start_o2 = 100,
  end_o2,
  start_pH,
  temp = 25,
  sal = 35,
  RQ = 1,
  TA = NULL,
  all_carb = FALSE
)

Arguments

start_o2

pO2 at the start of the measurement (% air saturation). Default is 100% air saturation.

end_o2

pO2 at the end of the measurment (% air saturation).

start_pH

seawater pH (total scale) at the start of the measurement.

temp

temperature (°C). Default is 25 °C.

sal

salinity (psu). Default is 35 psu. If sal < 26 psu, then TA must be provided.

RQ

respiratory quotient: ratio of CO2 produced / O2 consumed. Default is 1.

TA

(optional) total alkalinity (umol / kg). If undefined TA is estimated from salinity using guess_TA.

all_carb

logical. Should all carbonate chemistry parameters be returned? Default is FALSE.

Details

Given a known amount of oxygen consumed and an estimated respiratory quotient (see Q10), the amount of CO2 produced can be estimated. From this CO2 production estimate, the carbonate chemistry of the seawater can be estimated. Atmospheric pressure is assumed.

Value

If all_carb is FALSE, then a list of the predicted pH (total scale) at the end of the measurement and the predicted pCO2 (uatm) are returned. If all_carb is TRUE, then the predicted carbonate chemistry parameters are returned from carb.

Author(s)

Matthew A. Birk, [e-mail]

See Also

carb, guess_TA

Examples

predict_pH(end_o2 = 75, start_pH = 8.1)
predict_pH(start_o2 = 75, end_o2 = 50, start_pH = 7.96, temp = 15, sal = 33, RQ = 0.88)

# I know pH at the end was 7.8, but what was pH at the beginning?
predict_pH(start_o2 = 75, end_o2 = 100, start_pH = 8.013536) # reverse the order