Table 1 Important parameters for simulating 2-MT and 2-MG in the model and estimated lifetime of 2-MT and 2-MG in the gas and the aerosol aqueous phase.

From: New formation and fate of Isoprene SOA markers revealed by field data-constrained modeling

Parameters for simulating 2-MT and 2-MG

 

2-MT

2-MG

C* at 298 K (μg m−3)

14.6

30.3

\(\triangle {H}_{{vap}}\) (kJ mol−1)

117.7

130.0

H* at 298 K (M atm−1)

3.38 × 1010

5.25 × 108

\({k}_{{OH},{gas}}\) (cm3 molecule−1 s−1)

3.66 × 10−11

6.87 × 10−12

\({k}_{{OH},{aq}}\) (M−1 s−1)

1.14 × 109

0.97–1.41 × 109 a

 

Average conc.

2-MT lifetime (h)

2-MG lifetime (h)

OH gas (106 molec. cm−3)

OH aqueous (10−14 M)

Gas

Aq.

Gas

Aq.

Typical

1.00

1.00

7.6

24.4

13.5b (40.4)c

27.8

SOAS

1.23

0.71

6.2

34.1

11.0 (32.9)

38.9

PRD

1.75

0.78

4.3

31.4

7.7 (23.1)

35.8

West Pacific

1.19

1.11

6.4

22.0

11.3 (34.0)

25.0

Chinad

1.87

1.16

4.1

21.0

7.2 (21.6)

23.9

  1. aThe \({k}_{{OH},{aq}}\) for 2-MG is pH dependent, \({k}_{{OH},{aq}}\) = 9.7 × 108 M−1 s−1 at pH = 2; \({k}_{{OH},{aq}}\) = 1.41 × 109 M−1 s−1 at pH = 5.
  2. bbased on higher reaction rate kg,2-MG = 2.06 × 10−11 cm3 molecule−1 s−1 in the sensitive study.
  3. cbased on kg,2-MG = 6.87 × 10−12 cm3 molecule−1 s−1 in the base case simulation.
  4. dAverage OH radical concentrations at 14 sites.
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