Differences and Similarities of Central Asian, African, and Arctic Dust Composition from a Single Particle Perspective

Round 1

Reviewer 1 Report

Overall, the paper is interesting and has high scientific value. It will be better if the authors in their discussion part provide some possible application of the results on the dust composition from different sources, such as air quality or dust model improvement, source identification of dust at receptors and effects on fertilisation of ocean from sources. The introduction should also be expanded.

I recommend the paper to be published with some minor revisions. Some of the specific comments I have below should be addressed

(1) Reference errors occur at a number of places such as Page 2, line 26, line 46. Page 4 line 23, Page 6 line 10, Page 8 line 2 and 16

(2) Page 1, line 36: incomplete phrase "with atmospheric gaseous and liquid phases" [of particles] 

(3) Page 2, line 16-17: "... is of high interest for different processed". Please elaborate further on what are those processes

(4) Page 2, line 30: "As result" should be "As a result"

(5) Page 3, Table 2: " element-based" rather "element based"

(6) Page 4, line 1: "In a further approach" should be "In another approach"

(7) Page 6, line 6: "a relationship" rather "an relationship"

(8) Page 6, line 11: "Appendix A" rather "appendix A"

(9) Page 6 before the Results and Discussion part, a map showing the location of the measurement sites should be presented for readers to be familiarised with the various regions discussed in the paper. 

(10) Page 5, line 7 and page 6 line 3: should be Figure 2 rather than Figure 1

(11) Page 6, line 11: I don't understand the phrase "which in particular are in discussion contributing effectively.." Please clarify.

(12) Page 7 line 9, line 23: "Figure 4" rather than "Figure 2"

(13) page 9 line 26: "strengthens" rather than "hardens".

  

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Overall: The study analyses range of natural dust particles from 3 locations to identify their chemical composition and Fe solubility from these particles in the presence of externally and internally mixed Ca and at different acid processing intensities. The study adds knowledge to the field in terms of chemical composition and particle size dependency of the dusts from different source regions that are important for ocean fertilization. Hence, the paper is recommended for the publication after the major revisions.

Major Comments

1. Is there another reason to select Ca other than its’ abundance?
2. Line 77: Clarify… only particles with dust composition were regarded. May be a sentence or two to explain what usually considered as dust composition
3. Line 100: define non – dust component, I think the terminology used in this paper related to what is dust and what components are dust need to be clearly define in the beginning.
4. Line 147: Can you confirm the Fe mineralogy using XRD or other techniques, for the bulk of sample in different grain baskets?
5. Line 192: Authors mention that Fe in oxide grains are more bioavailable than structural state (which usually is clay). Is this correct or is its other way around? Or can we really generalize it with the knowledge we have? What about the oxidation state of Fe in these two categories of minerals when think about the bioavailability?
6. It is also worth mentioning few examples of internally mixed Fe Ca minerals such as Ca amphiboles with their relative natural abundance. That will give the reader an idea of what minerals the study is discussing.

Minor Comments

1. Title formatting
2. Line 58: replace processed with processes
3. Line 73, correct to … microscopy with Energy Dispersive X Ray…
4. Line 96: Can you do regular XRD to get the mineral composition?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I recommend to publish in the current format.