Understanding the Present-Day Spatiotemporal Variability of Precipitable Water Vapor over Ethiopia: A Comparative Study between ERA5 and GPS

Round 1

Reviewer 1 Report

The authors have incorporated all the suggested changes for improving the quality of the manuscript. The manuscript can be accepted for publication.

Reviewer 2 Report

The resubmitted manuscript "Understanding the present-day spatiotemporal variability of precipitable water vapor over Ethiopia: A comparative study between ERA5 and GPS" has certainly improved after responding to reviewers' comments. It is now much smoother and key points regarding the scope and objectives of the work have been addressed, also taking into account the scarcity of available data. The different sections are more homogeneous and the different items have been well presented.

As for the formatting, I suggest to make Fig. 2 smaller and to format the tables like Table 5, in order to be more compact and therefore easier to read.

After these minor changes, the paper can be accepted for publication.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The manuscript “The spatio-temporal variability of precipitable water vapour over Ethiopia from GPS, and its comparison with radiosonde and ERA5 data” presents new results, comparison, and validation between GPS, ERA5 and radiosonde data over Ethiopia, in particular the capability of capturing the seasonal and diurnal signals. A comparison has been done with daily precipitation to study the behaviour of PWV close to heavy rainfall events.

 

General comments/suggestions.

Observations from the period 2013-2020 were used for the study. As stated in the text, previous observations were available, at least in some of the selected stations. Why was the entire available dataset not used? Reprocessing of previous data could be helpful in understanding whether published results might be impacted by previous data processing strategy or parameterization. Also, only a few stations have common periods, so in my opinion adding older data could have helped reinforce the conclusions about comparison and validation.

Careful check of the entire text is required. There are spelling errors and English errors.

Please check the references carefully. In some cases the reference is presented long after the first time the topic is presented. For example, ERA-Interim is introduced first on line 89, but the reference is given on line 220. ERA5 is presented on line 99 and the reference is given on line 136.

Please, check the formatting of all Tables.

Abstract and in the manuscript:
There is some confusion between 8 Ethiopian stations and 26 stations outside the country and the 27 IGS analysed stations.

References:
Please check the style of the references which is not very homogeneous.
In reference 1 the year is wrong: 2011 instead of 2008.

 

Specific comments/suggestions.

Line 30-31. The sentence is not clear

Line 43. What does mi.e. stand for?

Figure 1. The stars indicating the GPS stations should be larger and perhaps not in red but in another colour that does not mix with the colours of the figure. 

Line 70.  orography

Lines 103-104. Please provide a brief description of sections 2-4 and not just of section 5.

Figure 2: Map colours should be more neutral. Topography details are not needed on this map. Its main purpose is to present the distribution of GPS stations, but this is not clear, because the red stars blend in with the background.

Table 2: GMT, ITRF2014, FES2004, VMF1 need the related references.

Line 180. Bold to highlight functions or equations is not necessary. Please also modify the following ones

Line 190. Please, delete the link and replace it with the reference [23].

Line 193. I suggest to move the link to the Data Availability Statement section, for readability.

Line 203. I suggest to move the link to the Data Availability Statement section, for readability.

Line 225. (see also Table 4). Tables must be numbered in order of appearance in the text. Table 4 is cited before Table 3.

Line 226. Δh is presented in the text and dz in Table 3.

Lines 232-234. Is this sentence part of the caption of Table 3? Or a note, or part of the text?

Line 239. I suggest to move the link to the Data Availability Statement section, for readability.

Line 241. I suggest to move the link to the Data Availability Statement section, for readability.

Line 245. 27 IGS stations are presented in the text and 26 IGS stations in Table 4.

Line 263. Delete “i.e.,”

Figure 6. The symbols should have the same colour of the lines, similar to the previous graphs.

Line 451. Until now the months have been explicitly named, while now acronyms are used, which are not explained anywhere.

Line 504. When the authors of the study are the subject of the sentence, I suggest to add the name: Zhang et al. [52} stated…..

Line 507. For example, Priego et al. [5] found ….

Line 511. In the Lisbon area, Benevides et al [53] found …

Line 520. Is 2013-2016 the correct period under study? GPS data for ARMI span from 2013 to 2015.

Figure 8 and Line 523. The rectangles look orange not grey.

Reviewer 2 Report

I appreciate the author's efforts in addressing various topics like seasonal variability, heavy rainfall event relationships, elevation-dependent relationships using Precipitable Water Vapor over Ethiopia. Though the analysis is extensive and intense, the manuscript lacks important research questions and objectives to address. I found this manuscript redundant with similar studies in previous years over Ethiopia (the same study area). I strongly suggest authors address the novelty and what this manuscript adds to the current knowledge of the scientific community. Please consider the comments as constructive than criticism for better research output. The authors can find the comments in the PDF file attached.

Comments for author File: Comments.pdf

Reviewer 3 Report

In this manuscript, the authors tried to report the comparison study of GPS PWV over Ethiopia using ERA5-PWV and radiosonde data. The manuscript is well organized and clearly written and the results are encouraging. It can be accepted in the present form.