Heat and Drought Have Exacerbated the Midday Depression Observed in a Subtropical Fir Forest by a Geostationary Satellite

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Heat and drought have exacerbated the midday depression observed in a subtropical fir forest by a geostationary satellite

 The topic of the paper is of great interest for the potential readers of the Journal. The rationale of the research is good; however, the objective and/or hypothesis must be improved. Maybe, you can order the paragraph between lines 66-76. I think is good is you can clarify which data is coming from (i) satellite data, (ii) global modelling based on satellite data, and (iii) field data from your study site. Besides, it is no clear if you take data from forests or not.

My main consideration is from methods. First, it only analyses “one forest point”, and it is no clear why. Most of the data coming from temporal satellite data (and modelling?), and they use 1 pixel, right? Why you not test many plantations? (e.g. 100 stands). In this sense, we have a pseudo-replication problem, and a lack of a landscape control of the results.

I agree that the flux tower (one plot) can be a good indicator for checking the satellite data and modelling, but the analyses must be checked in a higher landscape condition.

All the formulae must be deleted, they are published elsewhere (leave the references). Only must left here those formulae that YOU develop and are “new”.

Fig. 2, here you must add the “Mean Error” and the “Absolute Error” of the estimation. I think the correlation is low and non-significant.

Fig. 3 present the average is non sense... can you present it classifying the days? In example, high vs low temperature events, drought vs humid periods, etc..., or something that you analyse also in this paper. I think, these changes are interesting to be presented at different locations in the landscape, and not only the pixel that your plantation occurred.

The outputs can be divided in (1) validation of the model based on your tower, but with better statistical support, and (2) cross the satellite models consider better landscape control (more stands), types of days, years, and/or analysing other landscape gradients.

Please check many mistakes across the text (ej. line 28 or some red brackets).

Check style of references, and add ALL DOI for the references.

Comments on the Quality of English Language

Minor check is required.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have used the Himawari 8 meteorological geostationary satellite to analyze the trend of GPP and its associated meteorological parameters. Generally, the manuscript is well-written and well-structured. However, before its possible publication, the authors should clarify some parts of the manuscript.

From the manuscript, it is unclear whether the analysis is performed on data from a certain point or a forest region. If the analysis is performed on a single point, using Himawari 8 data cannot be justified. If a forest region is considered, the authors should provide the readers with more details.

Based on the results, the GPP from Himawari 8 and the flux 157 tower measurements were correlated with an R-squared of 0.63. Since the authors used satellite data, have these data been calibrated based on the tower measurements or not?

In Figure 6, the authors provide the probability of midday depression being triggered by climatic events. How are these probabilities estimated?

Most of the analyses are based on correlation that is suitable for linear relationships between variables and cannot be interpreted as causation or non-linear associations. I recommend using proper statistical tests for association analysis. 

Comments on the Quality of English Language

There are some typos in the manuscript. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I am thinking that the draft can be improved, including more landscape control, however, I am satisfied with the changes that you included in the draft. It is more clear now.

Check line 126, text are included in the title.

Remove spaces between paraghaps in section 2.3.

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

All my previous comments have been addressed. However, the authors should double-check the cited references. Some of the cited papers lack important information such as journal names (e.g.: 11 and 18)