Table 1 Parameterization of thickness-dependent uptake coefficients.

From: Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

Reaction

γ value

Thickness-dependent parameterizationa

Notes

HCl + Calcite -> CaCl2

(7.2 × 5) × 10−5

\(\frac{{2.66 \times 10^{ - 2}}}{{\sqrt C \,{\mathrm{d}}}}\)

Three flow tube experiment measurement cycles

(3.3 ± 0.6) × 10−7

to (3.0 ± 0.6) × 10−12 b

16 long-term uptake measurements at 3 different HCl concentrations

HNO3 + Calcite -> Ca(NO3)2

(2.5 ± 1.8) × 10−4

\(\frac{{1.43 \times 10^{ - 6}}}{{\mathrm{d}}}\)

or

\(\frac{{3.41}}{{\sqrt C d}}\)

Three flow tube experiment measurement cycles, error increased by background adsorption from HNO3

HNO3 + CaCl2 -> Ca(NO3)2

(2.5 ± 1.5) × 10−4

\(\frac{{1.43 \times 10^{ - 6}}}{{\mathrm{d}}}\)

or

\(\frac{{3.41}}{{\sqrt C d}}\)

Three measurement cycles by MS, error increased by background adsorption from HNO3

ClONO2 + CaCl2 -> Ca(NO3)2

(9.8 ± 9) × 10−5

\(\frac{{6.26 \times 10^{ - 6}}}{{\mathrm{d}}}\)

Three measurement cycles by MS

  1. All flow tube experiments were done at 215 K and long-term uptake experiments were done at 200 K. Mass spectrometer (MS) experiments were done at 1.6 Torr and long-term uptake experiments were done at ambient pressure.
  2. aFit to equation \(n_p = A(Ct)^{\frac{1}{2}}\) given the measurements from long-term uptake experiments. For the parameterizations, the dimensions for the concentration (C) and product layer thickness (d) are /cm3 and Ã…, respectively. np is the area-normalized product amount and t is time.
  3. bThe values listed were calculated from experiments with C = 5.4 × 1014/cm3, d = 0.05Å and C = 3.6 × 1017/cm3, d = 33.3, respectively.
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