Characterizing Rain Cells as Measured by a Ka-Band Nadir Radar Altimeter: First Results and Impact on Future Altimetry Missions

Round 1

Reviewer 1 Report

An interesting study, which has excellent results.

Author Response

The authors thank the reviewer for her/his good appraisal of the paper.
Note that an effort has been put on spell check.

Author Response File: Author Response.pdf

Reviewer 2 Report

Synopsis

This manuscript introduced ACECAL to characterize the rain cells from SARAL/AltiKa measurements. There are some major concerns listed below:

1. The current manuscript lacks the literature review of the SARAL/AltiKa mission since its launch in 2013.
2. Some statements are lack of proof to support (listed below)
3. Please highlight the significance of the findings.

Detailed Comments:

• Acronyms should be spelled out when they appear in the text for the first time.
• Redundant “the” in front of “Figure” or “Table”
• Lines 11-13: please rephrase this sentence “This study demonstrates…”
• Line 32: “characterized” should be “characterize”
• Line 36: missing “has” in front of “shown”
• Line 46: “a, innovative” should be “an innovative”
• Line 51: missing “has” in front of “shown”
• Line 52: redundant “a” in front of “better”
• Line 55: “is” should be “are”
• Line 58: “by” should be “of”
• Line 59: please specify “the same paper”
• Line 62: “on ground-based” should be “the ground-based”
• Line 69: please specify “this work”
• Line 72: “thant” should be “that”
• Line 73: missing “as” in front of “the CNES/NASA”
• Line 85: “reffered” should be “referred”
• Line 92: “analysis” should be “analyses”
• Line 96: redundant “retrieval of”
• Line 111: “estimates” should be “estimated”
• Line 114: is “200um” for “LWP”? LWP should have unit such as g/m2
• Line 124: could you please explain how “Figure 2 shows the limits of this approach”?
• Line 132: redundant “of” in front of “a long”
• Line 167: please specify “those events”
• Lines 168-169: could you please provide more background of “the neural network …in the learning database”? Are there references related to this statement?
• Line 173: redundant “of” in front of “about”
• The caption of Fig. 2: “Caracterization” should be “Chracterization”
• Line 185: “its” should be “their”
• Line 188: “refers” should be “refer”
• Line 192: “lye” should be “lie”
• Lines 199-201, “To increase the robustness of the polynomial fit, …”: could you please explain how much robustness could be increased by this approach?
• Line 206, 287, “Tournadre et al. 2015”: please indicate the reference
• Figure 3: could you please indicate what “this size” is (line 260)?
• Line 221: “this” should be “these”
• Line 228: “is” should be “are”, “reinforce to distinction” should be “reinforce the distinction”
• Line 230: missing “a” in front of “future”
• Lines 244-246: Please rephrase the sentence “The fit being …”
• Line 262: redundant “individual” in front of “peak”
• Lines 267-268: please rephrase the part “this definition … coefficient.”
• The top panel of Fig. 3: it’s hard to see the dashed black line. Could you please draw it overlaid on the blue dots and the red line?
• Line 278: “where is MP flagged” should be “where the MP is flagged”
• Lines 282-283, “Nevertheless, …” Could you please explain more explicitly?
• 4 is not referred to in the text
• Line 290: “the precipitation in not” should be “the precipitation is not”
• Line 294, “with no particular zonal distribution”: actually, there is a maximum in the ITCZ region.
• Lines 312-313, “it better reflects …” Please add proof to support this statement.
• Line 353: “below the Tropics” should be “in the Tropics”
• The caption of Fig. 6: “Top left” should be “Top”, “Top right” should be “Middle”, “red line” should be “black line”, and “solid green” should be “dashed black”
• 7: suggest adding a figure of the zonal mean that is similar to Fig. 6b.
• Line 371: “into” should be “in”
• Line 378: “compute” should be “computed”
• Line 383: “drop” should be “drops”

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper contains a detailed analysis of the effects of rain on Ka-band altimetry data, and describes a new algorithm for quantifying these effects. This analysis is both permitted and necessitated by the greater sensitivity to precipitation and the finer spatial resolution afforded by the higher frequency of the SARAL/AltiKa mission as compared with previous Ku-band altimeters. The new algorithm serves the dual purpose of better indicating regions where the altimetry data may be "corrupted" by rain, and of providing information on the rain rate and rain cell size. The analysis may also be useful for planning future altimetry missions. The work is carefully documented and the results are clearly presented.

Author Response

The authors thank the reviewer for her/his good appraisal of the paper.
Note that an effort has been put on spell check.

Author Response File: Author Response.pdf

Reviewer 4 Report

I have very few comments regarding this paper, as it is well prepared and solid. The main issues I have are cosmetic:

ACECAL should be defined within the abstract.

The legend on Figure 2 needs to be fixed so that is doesn't interfere with the plot. Figure 3 has the same problem to a lesser extent.

The authors need to be consistent with their use of Tb (or TB).

There is  a reference missing on line 162.

There are a significant number of minor grammatical errors (extra "the"s; improper plurals) and spelling mistakes:

Line 85: referred

Figure 2: Characterization

Line 192: lie

Line 194: criterion

Line 212: LWP

Line 280: complicated (or "made more complex")

Line 289: asymmetry

Figure 4: percentage

I don't think any of this detracts from the quality of the paper or a reader's ability to understand the work, but a thorough edit should clean up the language issues and improve the presentation of the work.

Author Response

The authors thank the reviewer for her/his comments.
We provided details answers and hope it will improve the general quality of this paper.
Reviewer comments:
I don't think any of this detracts from the quality of the paper or a reader's ability to understand the
work, but a thorough edit should clean up the language issues and improve the presentation of the
work.
(x) Moderate English changes required
ACECAL should be defined within the abstract.
Corrected
The legend on Figure 2 needs to be fixed so that is doesn't interfere with the plot.
Figure 3 has the same problem to a lesser extent.
Figure 2 and Figure 3 are updated accordingly.
The authors need to be consistent with their use of Tb (or TB).
The consistency is now insured and "Tb" references are removed.
There is a reference missing on line 162.
We were expecting to make a reference to a paper in preparation by other authors.
But unfortunately, the work is still under progress.
There are a significant number of minor grammatical errors (extra "the"s; improper plurals) and
spelling mistakes:
An effort has been put on spell check.
Line 85: referred
Corrected
Figure 2: Characterization
Corrected
Line 192: lie
Corrected
Line 194: criterion
Corrected
Line 212: LWP
Corrected
Line 280: complicated (or "made more complex")
Corrected
Line 289: asymmetry
Corrected
Figure 4: percentage
Corrected

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I thank the authors for considering my initial review. I only have some minor comments now:

• Line 37: “characterize” should be “characterizing”
• Line 41: “shown” should be “showed”
• Line 67: “type” should be “types”
• Line 99: “refered” should be “referred”
• Line 131: “sample” should be “samples”
• Line 227, 372: “to” should be “with”
• Line 231: “presenting” should be “presented”
• Line 236: missing “of” in front of “the peak”
• Line 237: “this” should be “these”
• Line 260: “being” should be “is”
• Line 337: “India” should be “Indian”
• Line 5 in the caption of Fig. 3: “to” should be “with”
• Line 362: redundant “here” in front of “in”
• Line 370: redundant “the” in front of “attenuation”
• Line 373: “in” should be “on”
• Line 394: redundant “Their” in front of “Figure”
• Line 431: “are” should be “is”
• Line 451: “to” should be “with”
• Line 454: redundant “to” in front of “the community”

Author Response

The authors thank again the reviewer for her/his very detailed review.

    Line 37: “characterize” should be “characterizing”
    corrected

    Line 41: “shown” should be “showed”
    corrected

    Line 67: “type” should be “types”
    corrected

    Line 99: “refered” should be “referred”
    corrected

    Line 131: “sample” should be “samples”
    corrected

    Line 227, 372: “to” should be “with”
    corrected. In the caption of Figure 3 as well.
     
    Line 231: “presenting” should be “presented”
    corrected

    Line 236: missing “of” in front of “the peak”
    corrected

    Line 237: “this” should be “these”
    corrected
    
    Line 260: “being” should be “is”
    I still would be in favor of the present participle "being" due to the structure of the sentence.
    "The final quality of the fit" is the cause of "their values are fixed"
    Another way to write it, would have been
    "since the final quality of the fit is weakly dependant" ... "then their values are fixed ..."
    Of course, if the conjugation is still wrong, I would correct it according to the Reviewer suggestion.
    
    Line 337: “India” should be “Indian”
    corrected
    
    Line 5 in the caption of Fig. 3: “to” should be “with”
    corrected
    
    Line 362: redundant “here” in front of “in”
    corrected
        
    Line 370: redundant “the” in front of “attenuation”
    corrected

    Line 373: “in” should be “on”
    corrected
    
    Line 394: redundant “Their” in front of “Figure”
    corrected
    
    Line 431: “are” should be “is”
    corrected

    Line 451: “to” should be “with”
    corrected

    Line 454: redundant “to” in front of “the community”
    corrected

Author Response File: Author Response.pdf