Combining High-Resolution Remote Sensing Products with a Crop Model to Estimate Carbon and Water Budget Components: Application to Sunflower

Round 1

Reviewer 1 Report

The manuscript “Combining high-resolution remote sensing products with a crop model to estimate carbon and water budget components: Application to sunflower” by Pique et al. is highly relevant for remote sensing applications using satellite and eddy covariance and crop modelling for regional estimates, and thus very relevant for the journal remote sensing. This is a dense read, but the authors did a great job forming a cohesive story, with sufficient detail to replicate the study or methods used therein. The introduction is well-structured with sufficient background information, describing the objectives of this research in detail. The description of remote sensing data is comprehensive and tables and figured summarize these nicely. Figure 3 is very useful with sifting through the dense results section, to understand what model included which parameters. The discussion is well laid out and covers results and limitations of this study well. I just have a few minor comments.

I was a bit confused about the growing seasons 2013-2015. It wasn’t clear to me from the methods section what crops were grown in those years, what rotation the fields were on and if all fields were on the same rotation. The models simulated those years, but from table 2 it appears that no sunflower crop was growing.

While reading I was wondering if the authors resampled the satellite images from the different sensors or if models were run separately by satellite? The section needs to be expanded upon what resolution was used, both in space and time. It wasn’t entirely clear to me if the satellite data served to calculate a time series of GAI or if the spatial information was used. Were satellite data interpolated to daily data?

In the results section 4.2.2 is duplicated (except for the last paragraph of the second 4.2.2) and should be removed

Figure 10 needs a higher font for the legend, the numbers are hard to read.

Author Response

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Reviewer 2 Report

Authors present the model estimates of carbon and water budget through combining the remote sensing products, which is applied on sunflower. Authors clearly state the relevance of the work, indicating the existing gap, and address the objective setup with sufficient details. The overall structure of the manuscript is well organized and written. So, I would recommend it for publication. A few minor comments are listed below for correcting and clarifying. Results: Line 465-466: “This period is easily identifiable on the scatter plots (Figure 5 C-D) and corresponds to the green points underestimated by the model” Would authors please add mean bias and slope for those parameters here? Negative NEE stands for sink, and positive represents source in current context, right? Line 551-553: “….for CY-07 (-4.3 and -10.8% for SAFYE-CO2IS and SAFY-CO2, respectively) and for CY-16 (+15 and +6.2% for SAFYE-CO2IS and SAFYE-CO2GSM, respectively),..” Please check “SAFYE-CO2GSM” in the second parenthesis, does it SAFYE-CO2 since authors talk about SAFYE-CO2 and SAFYE-CO2IS? Please check. Line 559: Section 4.2.2. Biomass and yield estimates, line 560-587 is repeated again in line 588 (4.2.2. Biomass and yield estimates), line 589-616. Please correct it. Technical comments: Line 396: not inversed or constrained -> constrained Line 435: “…SAFY-CO2 with the water module would decrease or improve the model’s outputs;” -> …SAFY-CO2 with the water module would improve the model’s outputs or not;”

Author Response

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Reviewer 3 Report

The study is well structured, soundly presented. All details in different sections are comprehensively described. With some updates in English grammar (present tense versus passed tense) and wording, I recommend the publication of the manuscript.

Here by some suggestions for improvement of the manuscript (the numbers below are the numbers of line in the draft):

22: please detail the abbreviation HSTR as it appears for the first time.

34: rather use "sufficiently accurate" instead of sufficient

34: rather use "more accurate"

52: use "Mediterranean-like climate" (add "climate")

53: use "severe water stress conditions"

54: delete " and cause large variations in crop growth" 

64: remove "(" , add ")".

66: rather use "de Wit school"

85 - 87: Regarding sunflower, either generic models (with......) or crop specific models (oilCrop-SUN......).

110: Italic please for "et al."

124: use "to" instead of "To"

139: From this section, for description of your activities, please use the past tense, for example, "brought"

141: use "were" instead of "are"

151: use "across" instead of "within"

159: delete "according to........" (repeated)

167: delete the word "see"

168: delete the word "However" (too many "however"s)

173:delete "see"

174 delete ")"

186: use rather "crop season" instead of "crop year"

189: past tense please ("was used")

190: past tense

194: past tense

203: delete "see"

288: replace "must" by "had to" (past tense)

293: use rather "sensor measurement mismatch"

315: please add a reference for your "underestimation" statement

319: Use "had been" instead of "was"

386-387: Please clarify this sentence by answering which enhancement?  Calculate what?

393 -397: Past tense

394: Please clarify the sentence between line 395 -397 (starting with "but when the last category of parameters......) by statement in the RESULTS section or by providing references

407: using past tense: was detailed in a referenced report [18]

426: using "crop season" instead of "crop years"

571: use "inaccurate" instead if "incorrect"

571: past tense please

572: use "the value derived from..."

594 - 616: this is a repetition of Lines 565 -587, should be deleted.

617: using "difficulty to reproduce"

622: past tense.

Author Response

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