co2_rate {respirometry}

Calculate CO2 to add to a respirometer intake flow

Description

Calculates the moles of CO2 gas to be added to a respirometer intake seawater flow to achieve the desired pCO2 in the respirometer. Useful for ocean acidification experiments where CO2 treatments are desired. Can be used for acclimation before a trial begins or for use with flow-through respirometry.

Usage

co2_rate(
  goal_pco2,
  init_pH,
  flow_rate,
  temp = 25,
  sal = 35,
  TA = NULL,
  atm_pres = 1013.25,
  MO2 = NULL,
  RQ = 1
)

Arguments

goal_pco2

the desired pCO2 in the respirometer (uatm).

init_pH

ambient pH of the intake flow (total scale).

flow_rate

rate of water flow into the respirometer (liters / minute).

temp

temperature (°C). Default is 25 °C.

sal

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

TA

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

atm_pres

atmospheric pressure (mbar). Default is 1013.25 mbar.

MO2

(optional) oxygen consumption rate (umol / hr). If defined, the CO2 to be added is reduced to compensate for the CO2 produced by the organism.

RQ

(optional) respiratory quotient: ratio of CO2 produced / O2 consumed. Only used if MO2 is defined. Default is 1.

Value

moles of CO2 gas to be added to the intake flow per minute.

Note

It is assumed that all of the CO2 added dissolves and remains in solution. This can be achieved (almost completely) by bubbling CO2 according to Jokiel et al. 2014.

Author(s)

Matthew A. Birk, [e-mail]

References

Jokiel PL, Bahr KD, Rodgers KS. 2014. Low-cost, high-flow mesocosm system for simulating ocean acidification with CO2 gas. Limnol Oceanogr Methods. 12:313–322.

See Also

co2_add, flush_carb, carb, peri_pump

Examples

# I want the respirometer to have a pCO2 = 1000 uatm. How much CO2 per minute do I need
# to add to the intake flow if the ambient pH is 8.1 and it is flowing at 3 LPM?
co2_rate(goal_pco2 = 1000, init_pH = 8.1, flow_rate = 3)