Table 2. SOA Yields for All Seeded Experimentsa.
| date | reaction pathway | VOC reacted (ppb) | total SOA mass (μg m–3) | SOA yield (OA + OrgNO3max) % | SOA yield (%) OrgNO3 with different R (NO2+:NO+): |
||
|---|---|---|---|---|---|---|---|
| R = 0.1 | 0.19 | OrgNO3 = max (0.15 to 0.27) | |||||
| 14 August 2018 | RO2 enhanced, dry,AS seed | 12.1 | 5.4 | 15.2 ± 3.4 | 3.9 ± 0.9 | 5.8 ± 1.3b | 5.8 ± 1.3 |
| 15 August 2018 | RO2 enhanced, humid, AS seed | 12.5 | 5.0 | 13.3 ± 2.3 | 3.4 ± 0.3 | 5.2 ± 1.1 | 6.4 ± 1.5 |
| 16 August 2018 | isom enhanced, humid, AS seed | 5.8 | 2.2 | 12.9 ± 2.2 | 2.4 ± 0.5 | 3.5 ± 0.7 | 5.8 ± 1.1 |
| 19 August 2018 | RO2 enhanced no O3, dry, AS seed | 4.3 | 0.5 | 4.0 ± 0.8 | 2.5 ± 0.5 | 3.2 ± 0.6 | 3.2 ± 0.6 |
| 21 August 2018 | RO2 + HO2, humid, AS seed | 3.5 | 0.36c | 3.5 ± 0.6c | 1.7 ± 0.3 | 2.5 ± 0.4 | 3.5 ± 0.6 |
a
In the OA + OrgNO3 column, yields reported were determined as the ratio of the sum of OA and maximum OrgNO3 to either (measured/modeled) Δisoprene. In the OrgNO3 columns, the ΔSOA is determined based on the OrgNO3 signal alone, with varying ratios as described in the text. The uncertainty is determined by assuming a 20% variation in the accuracy of the AMS mass concentration and a 10% error for the concentration of the consumed isoprene.
b
This yield uses R = 0.15, which is the maximum in this case.
c
Change in OA mass was not discernible, so these are based on maximum OrgNO3 mass only.