Dear Authors,
I have reviewed the manuscript and reviewers’ comments and would like to make a few comments of my own, which should be addressed before I can accept the manuscript for publication in ACP.

The manuscript is an extension of earlier work on oscillating parcels by Korolev (1995) and a variety of papers that have noted Ostwald ripening in cloud parcel models. It does go beyond Korolev (1995) in addressing the relative roles of solute and curvature for drop spectral broadening but it still lacks some perspective, and requires some important, not insignificant changes.

1) It feels like the study is looking for a niche. Under clean conditions, broadening is weaker whereas in polluted conditions there is progressively more broadening due to deactivation. The base case that is studied is polluted (Na=1000/cm3), presumably because such a case is more appropriate for a model that doesn’t include collision-coalescence. The cleaner conditions are relevant for the vast majority of maritime conditions. What importance should be placed on these processes given the idealized nature of the model set-up, especially the absence of collision-coalescence in cleaner conditions and deep clouds?
The study still misses important perspective and has not internalized results from many previous studies. As such it comes across as a bit “pedestrian”. Some of the references could be replaced by much older ones. One example is the parcel model work By David Johnson in the late 70s on GCCN. Another important paper that should be confronted: doi:10.1029/2008JD011286
In suggesting further references, I am not asking for a sprinkling of references in a variety of places but rather full engagement with the *ideas* in those papers. Given the sensitivity of the results to initial aerosol concentrations, a suggestion is to put your results in the perspective of saturation starved conditions vs. conditions where there is ample supply of vapor.

Supersaturation starved conditions: Larger nuclei suppressing the activation of smaller particles Ghan et al. (JAS 1998), Feingold and Kreidenweis (2000), Feingold et al. (2001), McFiggans et al. (2006, ACP), Reuter et al. 2009 www.atmos-chem-phys.net/9/7067/2009/

Mass accommodation requires more discussion since it can sometimes significantly change drop conc. (e.g., doi:10.1029/2004JD004750 Fig. 10)

2) Regarding activation/deactivation: Nowhere is it discussed that larger particles may not actually be activated since they have not reached the peak of their Kohler curve. (This doesn’t prevent them growing like drops and competing for water vapor.) Please check the particle sizes above which activation doesn’t occur and make sure your wording regarding activation/deactivation is accurate. When you claim that particles deactivate, have you checked that they did actually activate? The growth and then subsequent evaporation of droplets as the supersaturation is quenched is well documented. It can be found in text books such as Pruppacher and Klett or Rogers and Yau (see also review by McFiggans et al. 2006, section 3.)
3) A parameter that is very relevant but often not plotted/calculated is the drop concentration, n (why is CDNC sometimes used?). It should appear in the Table.
4) Pg 2: Line 18: This is incorrect. Broadening can increase or decrease albedo susceptibility depending on the broadening mechanism. (The appropriate papers are quoted but the results misunderstood.)
5) Conclusions: Pg 14, line 19: “We have used idealized simulations to find this new CDSD broadening mechanism” is an overstatement given earlier work on this topic. You would do well to highlight the incremental knowledge rather than overstate your case, especially given the highly idealized model set-up. E.g., a 6 km deep cloud will have huge water content and collection/sedimentation processes will be involved. At this point, the history of the drop trajectory through zones of variable qc will be much more important than the fluctuations in S. This ties into discussion on Pg 12 regarding residence time.
6) The wording “aerosol particles with different solute effects” implies that you have changed composition across the size distribution whereas my understanding is that what you mean is that larger particles have more dissolved material in them.
7) Pg 12: the discussion on the buffered nature of the system vis-à-vis the growth of the largest drops should be juxtaposed with the control that the largest CCN or GCCN have over the system in their ability to control the supersaturation and the activation of smaller drops.
8) The end of the Discussion seems to end without a clear message and could be much tighter.


Other:

1) While the authors make it clear what the nature of the microphysics scheme is, the term “bin” is not appropriate since it means the number of drops within a bin (i.e., between r and r+dr). The Lagrangian scheme used here is a moving grid scheme not a moving bin scheme. I realise that the reviewers had different thoughts.
2) Abstract, line 1: “which determine cloud albedo and rain formation”. “lifetime” is a very poorly defined concept in cloud physics.
3) There are numerous places where the text needs attention vis-à-vis grammar. Please read carefully and correct grammar/tighten the text as necessary.
4) Pg 4, line 2: results “confirm”…
5) Pg 5, line 7: remove (no GCCN). It has already been stated.
6) Pg 7, line 1: “CDSD evolution” is irreversible.
7) Pg 8, line 2: rephrase “why and which droplet will deactivate?”
8) Pg 8, reference to the quasi steady supersaturation should go back to early papers – e.g., earlier work by Squires (1952), Politovitch and Cooper (JAS, 1988) and later Korolev and Mazin (JAS 2003).
9) Comparison with observations (pg 11) should be considered carefully to see if conditions are similar. E.g., the Lu and Seinfeld paper was in a maritime setting with low drop concentrations. You should check the others as well.

Dear Authors,
I have read your revised manuscript and am satisfied that you have addressed the main issues.
I am happy to tentatively accept your manuscript subject to some minor technical corrections which are listed below.
Congratulations,
Graham