Thank you for your modifications to the manuscript in response to the reviewers' initial evaluation. Reviewer #2 had several suggestions for minor further revisions to the manuscript. I ask you to consider the changes this reviewer has suggested, as they seem likely to add clarity to some technical aspects of the work. I have summarized these suggestions below.

1) State in the abstract that the stated detection limits are typical averages under flight conditions.

2) State in both the text and the abstract that these detection limits are for CE=1 assumptions, and might change for different ambient conditions.

3) Consider including in the manuscript or SI the figure presented in the response to R2's initial comments showing agreement between the background variability method and the blanks.

4) In the detection limit discussion, replace “noise of the background” with “short-term variability of the background”.

5) Consider including, perhaps in the SI, a block diagram showing the control boxes/computers and the connected power boxes. And then ideally (in a different color/style) which piece of software runs on which computer and what the call hierarchy is.

6) Consider showing, possibly in the SI, the calibrations conducted in-between deployments, to provide information on long-term repeatability/stability.

7) Consider changing the stated uncertainty of the nitrate comparison in Fig 7a, which is really "just the overall IE uncertainty. Per Bahreini, that is 10% (explicitly stated in the SI) and should be used here [rather than 35%]."

8) Clearly state if you are defining CE using the operational definition (CE = Vchem/Vphys, where Vphys comes from an independent particle sizer), or the rigorous vaporizer particle bounce correction, which is independent of the agreement with any other instruments.

Thank you for your responses to the reviewers' comments. This is a very nice manuscript and, following a few very minor technical changes, should be ready for publication. Minor edits are:
1) In Figs. 5 and 7, please use different symbols rather than just different colors, for those with color vision impairment.
2) Please capitalize place names in titles to the Kloss et al. reference (Raikoke and Ulawun) and Vu et al. (Denver). There may be others in the reference list that I missed; please check carefully.