Interactive comment on “Fluorescent biological aerosol particle concentrations and size distributions measured with an ultraviolet aerodynamic particle sizer (UV-APS) in Central Europe”

This manuscript describes a new set of online ﬂuorescent biological aerosol particle (FBAP) observations taken over several months in Mainz, Germany using the UV-APS instrument. The current record of PBAP measurements is sparse, and therefore these observations are clearly valuable for characterizing the variability and contribution of PBAP to ambient aerosol. While the value of this unique dataset is clear, the pre-C11359 sentation of these results in this manuscript needs some improvement. The authors’ discussion of results is often excessive (examples given below), as is the description of certain rudimentary data collection tasks. Insight into the processes controlling the observed concentrations could have been provided by a more in depth analysis (the authors’ indicate that further statistical analysis is forthcoming) or ancillary datasets. As the authors have chosen not to do so here, I suggest that for publication in ACP, the presentation of results should be substantially abbreviated. characterizing the variability and of PBAP to aerosol.” critical producing a of quality, individual


Reviewer 2 Comments: RC 2.0
This manuscript describes a new set of online fluorescent biological aerosol particle (FBAP) observations taken over several months in Mainz, Germany using the UV-APS instrument. The current record of PBAP measurements is sparse, and therefore these observations are clearly valuable for characterizing the variability and contribution of PBAP to ambient aerosol. While the value of this unique dataset is clear, the pre-C11359 sentation of these results in this manuscript needs some improvement. The authors' discussion of results is often excessive (examples given below), as is the description of certain rudimentary data collection tasks. Insight into the processes controlling the observed concentrations could have been provided by a more in depth analysis (the authors' indicate that further statistical analysis is forthcoming) or ancillary datasets. As the authors have chosen not to do so here, I suggest that for publication in ACP, the presentation of results should be substantially abbreviated.
[Author Response, AR 2.0] The authors thank the reviewer for his/her positive assessment stating that "these observations are clearly valuable for characterizing the variability and contribution of PBAP to ambient aerosol." The critical comments have been constructive for producing a manuscript of higher quality, and individual comments are addressed individually below. f. The discussion of results in Section 3 could be substantially abbreviated.
[AR 2.1.f] As discussed in response to Reviewer 1, this section will be substantially abbreviated as suggested (by 509 and 197 words in sections 3.1.1 and 3.1.2, respectively). See AR 1.3 for more details.
[RC 2.2] 2. Several figures could be eliminated (Figure 1 and 4) as they provide redundant information, or merged together (Figure 9, 10, 11). In the case of this last I would recommend removing the diurnal panels as not all these exemplary periods were of similar duration, and the exemplary nature of the sampling is driven by the size distributions, not the temporal variability.
[AR 2.2] As suggested, Figures 1 and 4 have been moved to the online supplemental material to reduce redundancy and improve clarity. We disagree, however, with removing the time series parts of the panels from Figures 9 -11. For several of the exemplary size distributions, the temporal variability or stability of the peak(s) are C11361 important aspects of the information that makes the events unique. Removing these halves of the panels, therefore, will reduce the message conveyed. We chose to keep Figures 9 -11 from being merged, because we felt that a twelve panel figure would have been too small for final publication.
[RC 2.3] 3. Section 3.1.2: Rather than listing all the dates of elevated mass concentra-tions throughout the entire campaign, it would be helpful to indicate how many events matched the number concentrations peaks and if there were additional events where only mass concentrations peaked.
[AR 2.3] Again, as suggested the text in Section 3.1.2 has been substantially short-ened and clarified.
[RC 2.4] 4. Units on size distributions should be corrected. The correct units of dN/dD are cm-3um-1, the units for dM/dD should be ugm-3um-1 (see Seinfeld and Pandis equation 8.3 and figure 8.4). If these values have not been normalized for size then they should be reported as N and M.
[AR 2.4] The reviewer suggests that units for all number and mass size distributions shown and discussed in the manuscript be changed to cm-3um-1 and ugm-3um-1, re-spectively. However, we use logarithmically scaled distributions in which the diameter units cancel out. Please note that Equation 8.3 and Figure 8.4 refer to non-logarithmic distributions (dN/dD, not dN/dlogdD as used in the manuscript). For further information see Section 8. 1.3 and Equation 8.16 in Seinfeld and Pandis (2006) or other standard textbooks of aerosol and atmospheric science (e.g. Hinds, 1999;Baron and Willeke, 2001 Figures 4, 5 and 8: It would be helpful to include the standard deviation of the hourly means plotted in the top panels, to help distinguish whether maxima are statistically significant. [AR 2.5.b] Following up on this suggestion we will add bars (quartile areas) representing measurement variability in the revised version.