Articles | Volume 21, issue 13
© Author(s) 2021. This work is distributed underthe Creative Commons Attribution 4.0 License.
Tracer-based source apportioning of atmospheric organic carbon and the influence of anthropogenic emissions on secondary organic aerosol formation in Hong Kong
- Final revised paper (published on 14 Jul 2021)
- Preprint (discussion started on 20 Jan 2021)
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor |
: Report abuse
- RC1: 'Comment on acp-2021-32', Anonymous Referee #1, 29 Jan 2021
- RC2: 'Comment on acp-2021-32', Anonymous Referee #2, 11 Feb 2021
- RC3: 'Comment on acp-2021-32', Anonymous Referee #3, 27 Feb 2021
- AC1: 'Response to the reviewers' comments on acp-2021-32', Di Hu, 28 Apr 2021
- AC2: 'Response to the three reviewers' comments on acp-2021-32', Di Hu, 28 Apr 2021
Peer review completion
AR: Author's response | RR: Referee report | ED: Editor decision
AR by Di Hu on behalf of the Authors (29 Apr 2021)  Author's response Author's tracked changes Manuscript
ED: Referee Nomination & Report Request started (04 May 2021) by Nga Lee Ng
RR by Anonymous Referee #2 (13 May 2021)
ED: Publish as is (19 May 2021) by Nga Lee Ng
The authors reported measurement results of ambient particulate matter in Hong Kong using detailed chemical speciation methods. The results of the speciated organic portion by GC-MS suggested dominant contribution of secondary organic carbon (SOC) to total organic carbon (OC) measured. Focusing on the loading and sources of SOC, the authors used positive matrix factorization (PMF) and tracer-based method (TBM) to quantify the concentrations and source contributions of SOC in Hong Kong. Results showed that these two methods tracked well, but the latter method gave a much lower SOC loading compared to the former method (by a factor of 4). The authors went on to use linear correlation and multi-linear correlation to explore the relationships between different SOC types with other air pollutants or indicators, and found that nitrogen oxides (both NOx and NO3) and sulfate might play important roles in SOC formation in Hong Kong.
This is a rigorously performed field measurement study with very detailed chemical speciation information on ambient particulate matter in a typical urban environment in South China. The chemical characterization, data analysis, and discussion are scientifically sound. The manuscript is fairly well written. I therefore recommend Minor Revision with some comments provided below.
P2/L16: monoterpenes to monoterpene
P2/L30&31: please add “and” before the last item of a list.
P8/L203: I do not see any relevance to HO2 channel from the discussion above. The paragraph is mainly about ring-opening reaction of IEPOX under conditions of high LWC and low pH. Am I missing something here?
P10/L269-289: better to put this detailed description of PMF in the Method section.
P13/L364: just “Offenberg et al. (2017)”.
P14/L390: mass to air mass?
P15/L410: better use proper scientific notation, instead of engineering notation, for the temperature-dependent rate constant.