Articles | Volume 23, issue 15
https://doi.org/10.5194/acp-23-8789-2023
© Author(s) 2023. This work is distributed under the Creative Commons Attribution 4.0 License.
A dynamic parameterization of sulfuric acid–dimethylamine nucleation and its application in three-dimensional modeling
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- Final revised paper (published on 09 Aug 2023)
- Supplement to the final revised paper
- Preprint (discussion started on 31 Jan 2023)
- Supplement to the preprint
Interactive discussion
Status: closed
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor
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- RC1: 'Comment on acp-2023-15', Anonymous Referee #1, 19 Feb 2023
- RC2: 'Comment on acp-2023-15', Anonymous Referee #2, 17 Apr 2023
- AC1: 'Reply to Comment on acp-2023-15', Yuyang Li, 24 May 2023
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AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload
AR by Yuyang Li on behalf of the Authors (24 May 2023)
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ED: Publish subject to minor revisions (review by editor) (20 Jun 2023) by Kelley Barsanti
AR by Yuyang Li on behalf of the Authors (24 Jun 2023)
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ED: Publish as is (26 Jun 2023) by Kelley Barsanti
AR by Yuyang Li on behalf of the Authors (03 Jul 2023)
The study presents a parameterization of (mostly) previously published detailed modeling of sulfuric-acid- dimethylamine (DMA) new particle formation (NPF) and a modeling study in which the parameterization is applied over Beijing and found to explain aerosol number concentrations there. The parameterization of the detailed models and the method of simulating DMA concentrations are interesting, and useful. The paper could be improved by making the statements in the text more quantitative. I recommend that the paper is within scope of ACP and will be suitable for publication if the following mainly minor comments can be addressed.
Major comments
1. Need to evaluate condensation sink (CS) timeseries in WRF-chem simulations to show that simulated 1nm aerosol concentrations aren’t right for the wrong reasons. Please discuss results with reference to how sensitive the NPF rates are to the CS (Figure 2). While some information might be gained from the banana plots, they are hard to interpret quantitatively, and the size distribution is averaged over the time-period, which might hide significant discrepancies and might also help explain issue in simulating 2-10nm-sized aerosols.
2. Authors need to follow ACP open data standards: https://www.atmospheric-chemistry-and-physics.net/policies/data_policy.html. It is no longer sufficient to say "data are available from the authors on request'. Post simulation output and all code and data needed to reproduce figures on a repository, at a minimum.
Minor comments
The introduction refers to much of the relevant literature on NPF parameterizations but does not review prior modeling work in Beijing. Also need to discuss complementary modeling of SA-DMA clustering by Liu et al 2021, https://www.pnas.org/doi/epdf/10.1073/pnas.2108384118
Is there any dependence of the SA-DMA NPF rates on relative humidity?
The evaporation rate of 3.33s-1 is different to the one in Kuerten et al (2018), 0.1s-1 and likely other studies. Why?
What about synergistic effects involving ammonia or nitric acid (Glasoe et al, 2015; Liu et al 2021) and what about the possible role of amines other than DMA or even malic acid (Liu et al, Phys Chem Chem Phys, 2022 10.1039/D2CP03551K).
Sections 3.1 and 3.2 are too brief and qualitative: need to quantify the biases in the parameterized J rates versus the KM and CDS models using normalized mean bias and R^2.
Section 3.3: what are the R^2 values between the measured and simulated SA and DMA concentrations? Daytime SA is usually simulated within a factor 2 of measurements, which looks good, and the measurement uncertainty is likely close to a factor of 2 if not higher, so you can’t be expected to do much better than this – but a factor of 2 in SA is a factor of 16 in SA-DMA nucleation if the power law is 4. Doesn’t this introduce an important uncertainty in the simulated aerosol number concentration?
Section 3.4: In Figure 6, it looks like only about half of the NPF events simulated actually happened. It would be good to put some more precise numbers on this in the text. And in Figure 4, there seem to be too many Aitken mode aerosols most of the time. Doesn’t this suggest the SA-DMA NPF mechanism is too strong? What could cause these biases?
How frequently were relevant diagnostic variables output from WRF-chem?
Figure 1: the dashed line represents a factor of four variation in a) and an order of magnitude in b). There is no grey dashed line for +/-50% variation.
Line 308/Figure S6: Dunne et al (2016) included SA-DMA nucleation in their model but did not present it as part of their main analysis. Was only SA-H2O and SA-NH3-H2O nucleation from CLOUD included in this comparison, or were all mechanisms included? Please clarify.
All the Supplementary figures should be explicitly referred to in the text, or removed – but it may be enough to change S9-S16 to S9-S18 on line 362.
Would be good to try to link sensitivity studies more closely to observed biases in the results – discuss how uncertainties in X could lead to biases in Y etc.
Numerous small grammatical mistakes, e.g. missing “the”, use of “largely” to mean “greatly”, new words such as “majorly”, consistency between singular and plural verb forms (e.g 'the clusters… is…') throughout should be fixed before publication.