The field data of ice-nucleation particle (INP) concentrations from the studied regions are rare and invaluable. This study covers many topics, including but not limited to:

*Immersion freezing properties of ambient aerosol particles vs. subsurface seawater collected during the study presented vs. surface soil sample nearby the studied region, and

*Heat and H2O2 applications to assess protein denatured INP and organic-stripped INP concentrations etc.

These research topics are relevant to the ACP journal scope as ACP supports many INP-related papers. Though the data coverage is limited to the two-month campaign, the authors present sufficiently detailed results. The manuscript is a bit wordy but it is informative and reasonably well organized. The authors clearly address the necessity of future study (e.g., aged vs. nascent dust in terms of n_INP; P31L700-707), and this reviewer agrees with the addressed outlook. Overall, in the reviewer’s opinion, this paper is worth publishing in ACP and worth it to be shared in the atmospheric science community and beyond. This reviewer supports the publication of this paper in ACP after minor and technical revisions.

[Minor comments]

P6L170-174: It appears that multiple inlets were used for this study. Do all inlets come with a similar particle transmission/loss rate? Was it accounted for the size distribution data (or neglected)? Please clarify in the text.

P7L198-204: MARGA measured TSP but it seems other measurements (i.e., FMPS and OPC) assessed particles up to 10 um. Were there any >10 micron diameter particles measured during the campaign? Since the authors are adapting the MERRA-2 reanalysis data for the range of 0.1 – 10 micron (P2L49 & P8L220), further justification in the detected size consistency seems necessary here. Please elaborate.

P7L196-198: How did the authors estimate this overall uncertainty of 30%? The reviewer assumes this is some sort of systematic error. Please clarify in the text.

What were the measurement time resolutions of OPC and FMPS? Were the data time-averaged afterward, and that is what is reported in Table 1 for aerosol surface area concentration?

Were the statistical relative deviations of surface area concentrations within 30% over individual sampling times?

Table 1: Each sampling interval covers several hours. Air masses came from a similar source throughout individual sampling periods? The authors may consider showing the min-max ranges of surface area for each timestamp or some sort of data deviation range. They may help clarify to the readers if air masses were consistent over each sampling interval (or not).

Have the authors analyzed the correlation between INP concentration and ambient meteorological conditions? Were there any precipitations during the campaign, where rain may have washed out the dust and fresh particles (thus, showing low INP conc.?)?

Sect. 2.3. What is the uncertainty involved in the estimation of reported dust & sea salt mass concentrations? The MERRA-2 spatial scale seems big, and the reviewer wonders if such large-scale data can represent the pin-point dust concentration at the sampling point during the authors’ campaign. Is the MERRA-2 data sensitive and representative of the surface dust concentration at the sampling height that the authors employed?

Fig. S5: There seem some gaps between x1 and diluted results beyond the CI95% (e.g. f035, f042). Which n_INP (upper or lower bound) would be representative for the overlapping T region (i.e., ~-10 to -15 dC)?

P11L319-P12L325: How was this H2O2 treatment protocol developed? The reviewer thinks that it will be informative for the reader to know how the 1.6:0.8 mL ratio and this particular concentration of H2O2 were selected to be used in this study. It would be nice to have a reference here if the same procedure has been used in a previous study. Otherwise, please explain.

P12L323-325: Does the catalsase-added H2O2 suspension blank have a similar background freezing spectrum as compared to the field blanks? There is no suppression of background INP in pure water by these catalysts, correct? Perhaps, the authors can add the spectrum of the H2O2-treatment blank on Fig. S6 or may consider showing it elsewhere in this manuscript. 

Fig. 2: This reviewer encourages the authors to provide the error bars for the observation data (at least to some representative data points at higher and lower ends of T). They do not need to be statistical uncertainties. Can be systematic uncertainties instead.

P20L482-483: How were these 12 samples selected? The author may provide a brief explanation here or in Sect. 2.4 (~L315).

P21L501-504: Interesting. This release/exposure of INA core upon an application of heat can seemingly be a good future study topic in the IN research community. The authors may consider mentioning this somewhere as one of the outlook study topics.

P31L718: The authors may consider adding “potentially” in front of enabling. The proposed tagging would not warrant to link INP and aerosol properties as aerosol composition is not necessarily identical to INP composition. Perhaps, more reasonable properties to link in this context would be the relationship between ice crystal residual composition, n_s, and n_INP. Knowing that air masses are typically influenced by dust and maritime source (P5L149-150), other physicochemical properties of particles (e.g., mixing state) may play a substantial role over aerosol composition.

Fig. S12: The authors may include the explanation of the difference between open and solid symbols in the figure caption. Please clarify why the solid purple symbol data are not available for s007. Also, why does the highest T data point in s001 at T > -15 dC has a higher c_INP than the next data point at T of < -15 dC?

[Technical comments]

P1L1 vs. P2L35: ice-nucleating particles vs. ice nucleating particles – the reviewer suggests the authors be consistent in this terminology.

P2L47 vs. P11L295: ice nucleation site densities vs. ice-active surface site density – the authors may consider using consistent terminology.

P2L50 vs. P3L72: ice nucleation (IN) vs. ice-nucleating (IN) – please be sure the abbreviation is consistent throughout the manuscript.

P2L55-57: The reviewer is a bit confused here – the point that the authors want to make is that the ice nucleation active (INA) organics are limited in terms of quantity as compared to INA minerals, but it dominates the ice nucleation at T above -15 dC; therefore, they are important, correct? Currently, it sounds like organics are less important as INA component of aerosol particles than minerals by reading this part alone. The authors may rephrase this sentence accordingly.

P6L154: `

P9L256: SIO – abbreviation

P11L306: ice nucleating à ice nucleation active

P19L452: S7 appears after S8 & S9 (P13L372). Please fix the figure number sequence.

P27L611: ??? what does (6-20X)X mean?

P27L615-616: 155,000 in what physical unit?

[Misc. feedback]

P27L620-623: The reviewer likes this statement. This is one of the well-summarized take-home messages.

Review of Beall et al. 2022: Ice-Nucleating Particles Near Two Major Dust Source Regions

The study by Beall et al. 2022 evaluates INP concentrations in ambient air and sea water samples collected during the ship-borne AQABA campaign in the Red Sea, Gulf of Aden, Arabian Sea, Arabian Gulf, and part of the Mediterranean. The authors investigate changes in observed INP concentration with respect to origin and nature of the observed INPs. The authors put a specific emphasis on the discrimination of dust and marine contributions to the observed INPs in the air and underline the importance of organic and proteinaceous compounds on dust particles to their ice nucleation ability. The observations, analyses, and conclusions are of great interest to the scientific community and deserve publication in ACP. However, before publishing the study, the reviewer suggests addressing different general and specific comments, which hopefully help to improve the quality and impact of the manuscript.

LXXX refers to line XXX in the manuscript.

General comments:

Overall, the manuscript is a bit long-winded owed to the fact of an extensive analysis and many links to existing literature – what the reviewer highly appreciates. At some points the manuscript seemed repetitive (see specific comments below) and the readability/overview of the manuscript should be improved introducing more subsections (so far there are only two subsection titles for 17 pages of results) guiding the reader through the manuscript. Furthermore, (to the reviewer) the climax of the manuscript is reached with the conclusion of different parameterizations needed for fresh and aged dust, respectively (L620-623). Afterwards, the results continue, however, with the analysis of the sea water samples, which are also used to assess the partitioning of INPs arising from dessert and sea sources, a discussion that had previously been addressed using different proxies. The authors may want to cover the discussion of the sea samples earlier in the manuscript when discussion the source portioning and in order to work towards the conclusion L620-623. This could potentially increase the readability of the manuscript, but the reviewer leaves the decision of changing the manuscript structure up to the authors.

The reviewer highly appreciates the effort of the authors to apply their methodology also to a Saharan dust sample of the previous study by Niemand et al. 2012. What would be valuable is to let the reader know how the results in this study compare to the initial measurements of Niemand et al. 2012. Was the same ice nucleation (IN) activity observed? Could storage effects (e.g., Beall et al. 2020, Stopelli et al. 2014) have altered the observed IN activity? From the reviewer’s viewpoint this is essential information to assess how representative the reduction in IN activity due to the two treatments is, which is later used to support the conclusion for the need of different dust parameterizations. In addition, the sample preparation for analysis is not described in the manuscript and should be added in the methods section. Furthermore, the sample’s association to the study by Niemand et al. 2012 should be indicated at all instances in the text and in the caption of Figure 5 for clarity. The authors may consider plotting the original INP concentration observed by Niemand et al. 2012 to Figure 5.

Generally, storage effects on both the obtained filter and seawater samples seem to not be addressed in the manuscript. Given the storage of the filters of up to more than three years (L251), had a change in IN activity been observed, e.g., a decrease in average IN activity with storage time? Could a potential decrease due to storage also explain the reduced INP concentrations in the samples compare to previous work? This should be added to the discussion and be potentially mentioned in the conclusions, where the possible explanations for the reduced observed INP concentrations are listed. Furthermore, how long have the sea water samples been stored before analysis?

It is not entirely clear to the reviewer why the MERRA re-analysis data was chosen to assess the dust mass concentration albeit aerosol in situ observations were available on the ship. It is understood that using MERRA source regions could potentially be identified and the aerosol classes allow for the discrimination of different sources. However, these capabilities seem to not be used (for the source apportionment FLEXPART is used, for discrimination the sources it appears an AMS and a MARGA was used). Furthermore, from Table 1 it seems that the re-analysis average dust concentration did not necessarily relate to the in situ aerosol surface area. If the re-analysis is representative, a potential relation should exist to PM₁₀ derived from the in situ measurements assuming a representative dust density. To support the representativity of the re-analysis data, this relation should be explored and supported with e.g., a correlation coefficient. Would the usage of an in situ derived PM₁₀ compare better to the INP concentration (cf. Figure S7)? If so, the usage of an in situ derived PM₁₀ might be more appropriate. The authors may have addressed this approach in their analysis already. I would suggest elaborating briefly on their decision from where to take the dust concentration in the manuscript.

Throughout the manuscript, the authors need to perform a delicate balance between the analysis of individual samples and the implications to the overall big picture. At some locations in the manuscript very specific and detailed information of individual samples are given without putting it into context with other samples or the big picture (e.g., for L661-663, while the relation to the study of McCluskey et al. 2018 is very interesting to an INP researcher, indication in only one observed sample does not fully allow general conclusions). The authors may consider reading critically through their manuscript, removing side thoughts to streamline the manuscript. The reviewer acknowledges that the importance of such small connecting statements is subjective and leaves it up to the authors to assess their importance.

The presented supplementary information is appropriately chosen to support the understanding of the manuscript while not interfering with the main storyline of the manuscript. Despite being supplementary, the material should be presented in a more structured way, i.e., all figures should feature a corresponding caption beneath, and – in the reviewer’s opinion – a brief explanatory description as text should be given. Additionally, the reviewer encourages the authors to revise some of the figures in terms of readability, consistency, and quality. Specific comments follow below.

Moreover, the reviewer sees generally the need for more consistency throughout the manuscript in both the text and figures. Specific comments follow below.

Specific comments:

Abstract

No finding related to the SSW samples is mentioned in the abstract. The authors may consider adding an obtained insight from these samples.

L49: It should be annotated that the dust concentration was obtained from re-analysis data in contrast to the in situ measured INP samples.

Introduction

L120: The reviewer enjoyed the rather extensive but nicely written introduction to INP parameterizations.

Methods

L174: Different instruments were connected to different inlets. How do the different inlets compare, were the sampling lines similar per instrument? Furthermore, it would be very beneficial to have an overview picture/schematic of the different sampling sites to see their relative locations, e.g., are there any obstacles between the different inlets?

L176: The authors may want to consider adding the range of typical RHs during the campaign.

L177-L182: It would be beneficial to briefly explain the used thresholds/logical arguments of the filter flag.

L187-L188: Is there a reference for the mass ratio assumption? The authors may consider adding the values of used refractive indices and shapes, including a reference if possible.

L191: Is there a reference for the AMS data obtained during AQABA?

L198: How was the uncertainty of 30% derived? Please elaborate.

L208: Here again, an overview graphic (in the main text, supplementary, or referenced from a different publication) would strongly help to understand the relative locations.

L211: What is meant by “area-averaged”? Please elaborate.

L230: Are the ~25 m displacement vertically or horizontally?

L233: What determined the sampling length? What determined the sampling frequency? Please elaborate.

L238-L242: Just to ensure: The relative wind direction towards the sampling unit has not been used to switch off the sampling pump?

L253: How was the shaking realized?

Eq. (1) + E1. (2): Consider adding a reference for the equations.

L287-L289: Given the spread of two orders of magnitude of the background INP concentration, the reviewer does not fully agree with the used background correction methodology. The degree of contamination of the field blanks when inserting them in the sampling unit and removing them could likely be a function of the ambient aerosol concentration while taking the field blank. Thus, subtracting the timely closest background from a sample might be more meaningful. However, the reviewer acknowledges that this change would not substantially affect the background corrected INP concentrations and does not need to be implemented.

L293: When overlapping, were the INP concentrations from diluted samples combined with the INP concentrations from the undiluted samples? If so, please specify.

Eq. (3) + Eq (4): While Eq. 3 and Eq. 4 are presented in Kanji et al. 2017, a reference like e.g., Hiranuma et al. 2015 explaining the approximation to A_tot might be more helpful to the reader.

L315: What was the motivation/criteria for the selection of the specific 12 samples? Please elaborate.

L315-L338: Has this procedure/protocol of heating and hydrogen peroxide treatment been previously described? If yes, the authors may want to shorten the description and cite the existing literature.

L345-L346: Also here, how were the 5 samples selected? Please elaborate.

Line 349ff: How frequent were back trajectories released, how many were investigated per filter sample, and which time (e.g., start or end time of sampling) was considered for choosing the displayed trajectories? Is there a reason for choosing 72 hours? Furthermore, the authors may consider indicating the trajectory locations in plots S8 and S9 where the trajectories were below a certain threshold height indicating potential air mass uptake.

Results

L415: It could be insightful to add a flag to Table 1 to indicate which samples are thought to be sampled during dust events. Otherwise consider changing “(Table 1)” to “(dust concentration > 50 µg m^-3, see Table 1)”

L415-L416: How was a high probability of dominant dust contributions determined? To the reviewer’s understanding this assessment is based on increased PM₁₀ loadings of the re-analysis data. However, it seems that the reanalysis data does not necessarily correlate with the in situ observed particle surface area concentration (Figure S7). Has the relation between re-analysis data and in situ observations been investigated to support the assessment of dust contributions solely on re-analysis data? If no relation prevails the reviewer would suggest tempering the statement from high probability to likely given a potential absence of in situ increased concentrations.

L428+L429: In Table 1 the seasalt concentration is given. If this is used as proxy for SSA, the authors should specify this and explain their reasoning for choosing this proxy.

L437-L439: The higher relative abundance of dust over sea salt concentration seems to be the essential part of the last two paragraphs. If the authors see a possibility, they could abridge their argumentation in L415-L443 to reach this statement.

L450: What is meant by efficiencies? Please elaborate.

L455: The exclusion of the sample by Price et al. 2018 seems a little bit arbitrary. Could the authors add the observed surface area of the excluded samples and the maximal observed surface area during the present study to relate the two observational ranges?

L459: Is there also a possibility for regional difference affecting the aerosol/INPs differently (Price et al. 2018 sampled at the western end of the Sahara)?

L492+: In the following, is sensitivity referred to as degradation? The authors may specify that.

L543-L546: Is there a plot supporting this argument?

L550-L560: This passage has more introductory character. The authors may consider moving it to the introduction

L585: Cite the referred studies.

L626: Does Figure 5 refer to the soil sample used previously in the Niemand et al. 2012 study? What about the ambient aerosol observations during the research cruise? The authors may consider including the results presented in Figure 4 to the discussion here.

L644: Add a reference for the SSW samples collected at the Scripps Memorial Pier. If the data hast not been published yet, the authors should add a description of the sampling and analysis in the methods section.

L657: Why were not all samples processed? Please elaborate here or in the methods section.

L661-L663: The reviewer is not fully sure what this result adds to the discussion. The authors should consider elaborating on this and highlight how the observation in an individual sample relates to a bigger implication.

L670-671: The authors may consider adding the total number of observed samples.

Conclusions

L678: The authors should add a quantitative statement on what is meant by “showed agreement” for the different data they refer to.

L685: The authors may consider stating explicitly the temperature ranges they refer to in the conclusions.

L685-L689: To the reviewer this statement has rather introductory than concluding character. The authors may consider either moving the sentence to the introduction or shortening the statement and directly combining it with observation of the study.

L689-L691: The authors may add that the analyzed sample originates from the analyzed samples in Niemand et al. 2012.

L698: Also here, what is considered a well agreement? Agreement within an order of magnitude? Please support with a quantitative statement.

L700-L707: In the reviewer’s opinion, the possibility of sample degradation and the potential impact of sampling close to the ground (as discussed in the results) should be added.

L709: The authors may want to add a brief explanation of the working principle/data basis of the methods by Gong et al. 2020 to the sentence.

Editorial notes:

L37: The authors may consider changing “reflectivity, and precipitation efficiency” to “radiative properties, and precipitation initiation efficiency”, to avoid using reflectivity, which is often connotated to radar observations, and be more specific about the role of INPs towards precipitation. This comment also applies to other occurrences in the manuscript.

L47: Increase consistency: sometimes e.g., “1-3 orders of magnitude” is used, sometimes “one to three orders of magnitude”.

L50: Despite standard in our community, the authors may want to specify the usage of “hydrogen peroxide”. In the manuscript, different versions (peroxide, hydrogen peroxide, H₂O₂) – the authors may use one version for consistency.

L51: Consistency: here ≥ is used, whereas in L56 and L58 >.

L57: Consistency: modest (three instances) or moderate?

L67: Consider adding “primary” to “ice formation”.

L73: The long-term INP observations of Brunner et al. 2021 may be an additional suitable reference for this statement.

L76: Consider adding “average” to “global dust loading”.

L79: emissions → emission.

L89: Consider adding “by number” or “by mass” after “dominant”.

L111: Consider introducing A13 here as well.

L112+L114: Add ‘hereafter,’ before introducing the abbreviations of N12 and D15.

L121: Consider adding “in situ” before “INP measurements”.

L126: Consider adding “west” before “of the Sahara”.

L144: “SSA” not defined yet.

L149-L159: If further subsections are added to the manuscript, the different sections could be added here after the individual analysis steps to allow easy finding of specific parts of the manuscript.

L152: Consider adding “ambient” before “aerosol sample”.

L156: Leave out “ ’ ”

L190: d_opt, d_geo, and PM₁ are not defined yet.

L198: Consider adding “geometric diameter” after “µm”.

L254: At different instances “-fold”, “x”, or “-times” are used. Consider using one version throughout the manuscript.

L256: SIO not defined.

L265: In the reviewer’s perception, the ‘INP’ subscript should not be in italics, i.e. n_INP. This applies throughout the manuscript, including the figures. Further, the authors should consistently use n_INP or INP concentration in the text.

L267: Consider adding “drop” before “volume”

L273-L290: Is n_INP in bold font intended?

L282: When comparing to Figure S6 the concentrations seem different at -20 °C.

L285: The linear regression seems to have been done on the log-transformed data. If so, please specify.

L314: °K → K

L328-L331: Maybe add that the results of each test are indicated in the corresponding figures.

L362: The referred abbreviation PM₁₀ does not appear in Table 1.

Table 1: Remove “unt” from sample ID to stay consistent with text. Consider adding (°N) and (°E) to latitude and longitude. At what sampling time are the presented latitudes and longitudes (start or stop datetime?). To enrich the information of the table, the authors may consider adding the INP concentration at an exemplary temperature.

L392: Has M18 already been introduced?

L396: Did the authors mean to refer to Yang et al. 2020?

L397+L398+L401: The authors may consider adding the sample IDs of the mentioned samples/spectra.

L403: It may not be entirely clear to which study “same region” refers to.

L433: DMSO₂ and VOCs remain undefined.

L452: Figure S7 should be number S9.

L467: DeMott et al. 2015a → DeMott et al. 2015

L533+L595: Consistency: change “dusty” to “dust-laden”.

L534: “N.” → “North”

L565+L566: Consider rephrasing the citation text (“e.g.”) as it is not directly evident what statement the citation supports.

L569: The authors consider adding exemplary references for the mixed and contradictory results already here.

L581: Both “>” and “below” is used. For consistency the authors may want to use </> or below/above consistently throughout the manuscript.

L611: Remove second “x”.

L612: Remove whitespace.

L616: Missing unit after “(±65,000)”.

L620: For Kanji et al. 2017 being a summary, consider putting it last in line and add “and references therein”.

L629: What are the temperature ranges considered “high” or “moderate”? The authors should consider adding the temperature ranges here, and/or explicitly introduce the referred temperature ranges earlier in the manuscript.

L660: “POV” was already introduced.

L663: “DOC” was already introduced.

L670: Consider adding “Observed” before “INP concentration”.

L675: The authors may consider adding that the PM₁₀ observations were obtained from re-analysis.

Editorial notes on the figures:

Generally, many of the figures (e.g., Figure 3, 4, and 6) feature strange gray lines not belonging to the plot itself. Further the indication of units is inconsistent, e.g., “°C“ after “Temperature” is never set in brackets. Legends that apply to different subplots could be put aside of the subplots and not within one subplot. The reviewer kindly asks the authors to check all their figures (including supplement) to enhance their quality.

Figure 1: Datapoints at 25°N/35°E are overlaying and barely visible. Change order or add some alpha to scatters. “µm” in colorbar.

Figure 2: The readability of the plot may be increased when using generally open symbols in combination with some alpha.

Figure 3: Mention the errorbars in caption. Maybe mark sample f020 in plot (a) as reference. Consider stretching the y-axis limits in (b).

Figure 4: The labels of the subfigures need to be increased. “INPs” to “INP concentrations” in caption.

Figure 6: Shouldn’t the y-label read n_INP,L? “INP spectrum” to “INP spectra”. Also name the number of samples from the other studies in the caption.

Figure S1: It seems that f006-f009 and f018+f019 overlap. Were several sampling units running at the same time? If so, this should be mentioned in the methods section.

Figure S3: The authors may consider reducing the dot size for readability.

Figure S5: In consistency to Figure 5, the dilutions could be indicated with a different marker than undiluted samples.

Figure S7: The labels are rather small and could be increased in size. What correlation coefficient was used? To the reviewer’s perception Spearman’s correlation coefficient should be used. The reviewer is not fully sure about the expressiveness of the figure. Maybe a table with Spearman correlation coefficients between the INP concentration and both surface area and dust concentration at all temperatures could help for a more complete picture.

Figures S8+S9: The authors may consider indicating only locations of the trajectories below a certain height threshold.

Figure S9: To add information, the cross of the missing sample could be colored according to the observed dust concentration.

Figure S11: There seems to be data gaps, which are indicated in black as is the land contour. Color either the land or data gaps in a different color. Remove gray lines around colorbar. Add shown quantity to the colorbar.

Figure S12: Shouldn’t the y-label read “n_INP,L (mL^-1)”?

References

Beall, C. M., Lucero, D., Hill, T. C., DeMott, P. J., Stokes, M. D., and Prather, K. A.: Best practices for precipitation sample storage for offline studies of ice nucleation in marine and coastal environments, Atmos. Meas. Tech., 13, 6473–6486, https://doi.org/10.5194/amt-13-6473-2020, 2020.

Brunner, C., Brem, B. T., Collaud Coen, M., Conen, F., Hervo, M., Henne, S., Steinbacher, M., Gysel-Beer, M., and Kanji, Z. A.: The contribution of Saharan dust to the ice-nucleating particle concentrations at the High Altitude Station Jungfraujoch (3580 m a.s.l.), Switzerland, Atmos. Chem. Phys., 21, 18029–18053, https://doi.org/10.5194/acp-21-18029-2021, 2021.

DeMott et al. 2015 from the manuscript.

Gong et al. 2020 from the manuscript.

Hiranuma, N., Augustin-Bauditz, S., Bingemer, H., Budke, C., Curtius, J., Danielczok, A., Diehl, K., Dreischmeier, K., Ebert, M., Frank, F., Hoffmann, N., Kandler, K., Kiselev, A., Koop, T., Leisner, T., Möhler, O., Nillius, B., Peckhaus, A., Rose, D., Weinbruch, S., Wex, H., Boose, Y., DeMott, P. J., Hader, J. D., Hill, T. C. J., Kanji, Z. A., Kulkarni, G., Levin, E. J. T., McCluskey, C. S., Murakami, M., Murray, B. J., Niedermeier, D., Petters, M. D., O'Sullivan, D., Saito, A., Schill, G. P., Tajiri, T., Tolbert, M. A., Welti, A., Whale, T. F., Wright, T. P., and Yamashita, K.: A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of 17 ice nucleation measurement techniques, Atmos. Chem. Phys., 15, 2489–2518, https://doi.org/10.5194/acp-15-2489-2015, 2015.

Kanji et al. 2017 from the manuscript.

McCluskey et al. 2018 from the manuscript.

Niemand et al. 2012 from the manuscript.

Price et al. 2018 from manuscript.

Stopelli, E., Conen, F., Zimmermann, L., Alewell, C., and Morris, C. E.: Freezing nucleation apparatus puts new slant on study of biological ice nucleators in precipitation, Atmos. Meas. Tech., 7, 129–134, https://doi.org/10.5194/amt-7-129-2014, 2014.

Yang et al. 2020 from manuscript.

See the supplement