General Comments:

This paper appears to be the first global modeling study of INPs where the cloud radiative effects (CREs) of respective INP species are estimated.  The methods used appear to be state-of-the-science and the results conform to physical intuition.  The paper is well written and well organized.  The paper could be improved by adding a discussion of how an INP is defined, considering the temperature-dependent nucleating efficiency of an INP species.  Some other ways to improve this paper are listed below.  I recommend this paper for publication in ACP with minor revisions.

Major Comments:

Lines 21 – 26: Are there studies showing how increasing the ice fraction decreases cloud lifetime and cloud fraction due to the higher fall speeds of ice particles?  This will affect the CRE.  If so, this process with references should be mentioned.  Relevant references might be Mitchell et al. (2008, GRL) and Eidhammer et al. (2017, J. Climate, p. 618). 

Lines 41 – 43:  Righi et al. (2025, ACP) may be relevant here since they show BC from aviation is not a significant INP.

Table 1:  Please add median particle size to Table 1.  This will make it clearer that the greater mass concentration of dust translates to a higher INP number concentration. (For example, anomalously large INPs may dominate the mass concentration but not the number concentration.)

Lines 89 – 91: Does this imply that the INP number concentration = the ice crystal number concentration (not the ice particle number concentration that is affected by aggregation)?  More specifically, how are INPs defined?  Do all INPs form ice crystals under favorable conditions?  Or is there a probability, like 10%, that an INP will form an ice crystal under favorable conditions?  If the former, then INP conc. = aerosol species # conc. x probability?  In either case, please clearly define INP.  It appears that Table 1 provides references for the INP probabilities used in this study.  Please discuss how these probabilities are used.

Lines 110 – 113: Roughly, what are the highest latitudes sampled by MODIS?  This may inform the reader which latitudes have the highest confidence.

Lines 119 – 121: Righi et al. (2025, ACP) also found that aviation soot has no significant impact on the INP concentration.  Consider adding this reference above to help justify your practice of ignoring anthropogenic BC as an INP source.

Lines 132 – 135: Ice nucleating ability tends to decrease with increasing temperature, but here it abruptly increases moving from -9 C to -5 C.  Was there a typo or is there a physical reason for this?  If the latter, please provide the reason.

Lines 204 – 208:  Same comment as for Lines 89 – 91.

Technical Comments:

Figure S8 in the Supplement:  Panels marked Jan 2016 through Jul 2016 should be dated as 2017.

General comments:

This study incorporated various aerosol species acting as INPs into a global aerosol-climate model to demonstrate how non-dust aerosols are important to explain the overall INP abundance on the global scale, together with estimates of cloud radiative effect induced by them. The study convincingly shows a significant contribution of non-dust aerosols to INPs and pointed out an importance of observational constraint on INP-temperature spectra to better quantify cloud radiative effect due to aerosol-cloud interactions through INPs. I would recommend the manuscript be accepted for publication after the authors appropriately clarified several points described below.

Specific comments:

Section 1: There is a recent study by Imura and Suzuki (doi:10.1175/JCLI-D-24-0335.1) that investigated climatic impact of differing INP-temperature spectra through precipitation process, which I think is relevant to the scope of this study. The authors should discuss the paper in the context described in introduction.

Section 2.1: It would be useful to add the plot that compares how INP number concentration depends on temperature, or the so-called INP-temperature spectra for various aerosol species treated in this study. Such a plot would be very nice to illustrate how different aerosol species newly considered in this study have different efficiencies as INPs. The plot should also include the observationally constrained function of bacteria described in Section 2.3.

Line 91-93: I don’t understand what this sentence means. Why do you talk about the treatment of bioaerosols, MOA and BC here in this subsection for dust? Please clarify what “the same computational approach” means.

Line 104-106: Is there no temperature dependence for bioaerosols assumed here?

Line 134-136: Do these multiplication factors mean the factors relative to the Base simulation?

Line 145: “between all-sky and clear-sky conditions”: Is this not a “clean-sky” CRE? That is, does the cloud radiative forcing here includes the effect of light-absorbing aerosols on cloud radiative effect? Please clarify.

Line 290-292: I don’t understand what this sentence means. Can you explain more clearly how the fewer total INPs, more water droplets and fewer ice crystals at the temperature warmer than -10C relate to the higher sensitivity of bioaerosols than dust?

Line 294-295: Does this mean that the dust and bioaerosol contributions to overall CRE are mostly linear?

Line 301-303 and Table 2: The table shows only the “All INP sources” value of CRE. Are the CREs from aerosol species other than bacteria are same between the observationally constrained and Base simulations? Namely, does the difference in CRE from the all INP sources between the two simulations (0.64 vs 0.24 Wm-2) come from only the bioaerosol-induced CRE? Please clarify.

Minor points:

Figure 3 caption: orange -> yellow. To my eye, the color of dust looks more like yellow rather than orange.

Review of 

Global Modeling of Ice Nucleating Particles of Multiple Aerosol Species and Associated Cloud Radiative Effects

by Kawai et al.

General comment:

In this study a global climate model with a detailed aerosol and cloud microphysics scheme is used to investigate the global distribution of ice nucleating particles and their impact on the radiative effects of clouds.

Generally, this is a well written manuscript that constitutes a valuable contribution to ACP. However, I have some minor comments about the model description and some parts of the evaluation. Therefore I recommend minor revision for the manuscript, before it should be accepted. In the following I will explain my concerns in detail.

Minor points:

Aerosol bin microphysics:

It is not clear to me, why a really complex aerosol scheme based on a bin approach is used in the investigation. Many other aerosol climate models use bulk model schemes to derive the global distributions of aerosols and INs. I think there are good reasons for using such a scheme, but this should be explained in the manuscript.

Coupling of aerosols and clouds schemes:

Generally, the overall description of the aerosol and cloud models used in the GCM lacks details and is very short. While for the aerosol investigations a bin model is used, the cloud model (as far as I know the CAM model) is based on a bulk scheme. How do the properties of aerosols (in a bin scheme) translate into the cloud bulk scheme? The authors should explain the overall concept and give more details about the schemes. For instance, it is not clear if there is a discrimination in the ice modes by ice formation pathways or if just one class for all ice nucleation pathways is used.

IN Parameterizations:

There is not much information about the ice nucleation scheme; somewhere in the text it is mentioned that for the IN parameterizations a purely temperature dependent approach is used. This is somewhat surprising, since from the bin aerosol scheme there should be much more information available in order to use a more detailed IN scheme. There is probably a reason for that, which should be stated in the manuscript.

Fits for CRE (section 2.4)

In the text the fit procedure is vaguely described with a reference to the supplement. Actually, just from the text this procedure cannot be understood in a meaningful way. I would recommend to include the figure (fig S2) into the main part of the manuscript.

Lack of MOA over China

From figure 1 one can conclude that there is no MOA contribution to INPs over China. Why is this so? Can this be explained by the wind fields (no transport of marine air to the continent) or is it just because the dust contribution is so large that the others cannot be seen? For figure 1 and 3 it would be good to have the numbers (including the fraction of contributions) in a separate table.

Aerosol distribution in the upper levels

It seems that for the upper levels (i.e. at cold temperatures of T~ -25°C, see comparison with Tokyo) the agreement with the observations is less convincing. Can you give some (physical/chemical/meteorological) reasons for that?