Generating seamless global daily AMSR2 soil moisture (SGD-SM) long-term products for the years 2013–2019

Zhang, Qiang; Yuan, Qiangqiang; Li, Jie; Wang, Yuan; Sun, Fujun; Zhang, Liangpei

doi:https://doi.org/10.5194/essd-13-1385-2021

Articles | Volume 13, issue 3

https://doi.org/10.5194/essd-13-1385-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/essd-13-1385-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 13, issue 3

Data description paper

|

31 Mar 2021

Data description paper |

| 31 Mar 2021

Generating seamless global daily AMSR2 soil moisture (SGD-SM) long-term products for the years 2013–2019

Qiang Zhang, Qiangqiang Yuan, Jie Li, Yuan Wang, Fujun Sun, and Liangpei Zhang

Download

Final revised paper (published on 31 Mar 2021)
Supplement to the final revised paper
Preprint (discussion started on 23 Nov 2020)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC1: 'Comments on SGD-SM: Generating Seamless Global Daily AMSR2 Soil Moisture Long-term Productions (2013–2019)', Anonymous Referee #1, 01 Dec 2020
- AC1: 'Author Reply on RC1', Qiang Zhang, 12 Jan 2021
RC2: 'Review on "SGD-SM: Generating Seamless Global Daily AMSR2 Soil Moisture Long-term Productions (2013–2019)"', Anonymous Referee #2, 11 Dec 2020
- AC2: 'Author Reply on RC2', Qiang Zhang, 12 Jan 2021
RC3: 'Review of ESSD-2020-353, titled “SGD-SM: Generating Seamless Global Daily AMSR2 Soil Moisture Long-term Productions (2013-2019)” by Zhang et al.', Anonymous Referee #3, 11 Dec 2020
- AC3: 'Author Reply on RC3', Qiang Zhang, 12 Jan 2021
RC4: 'Review', Anonymous Referee #4, 31 Dec 2020
- AC4: 'Author Reply on RC4', Qiang Zhang, 12 Jan 2021

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Qiang Zhang on behalf of the Authors (21 Jan 2021) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (02 Feb 2021) by Giulio G.R. Iovine

RR by Anonymous Referee #3 (15 Feb 2021)

Suggestions for revision or reasons for rejection

Great thanks to the authors for their efforts in addressing the comment. This reviewer has three major comments for the author’ further consideration, and suggests to accept this paper after minor revisions.

Major comments:

1. Figure 1b shows no selected in-situ measurements at China and Russia for comparisons. As such, the reviewer is a bit less convinced by the quality of data at Asia, especially at the Tibetan Plateau where the fast changing atmospheric conditions complicate soil moisture retrieval and therefore the AMSR2 product. The author may check ‘Zhang P, Zheng D, van der Velde R, Wen J, Zeng Y, Wang X, Wang Z, Chen J, Su Z. Status of the Tibetan Plateau observatory (Tibet-Obs) and a 10-year (2009–2019) surface soil moisture dataset. Earth System Science Data Discussions. 2020 Oct 16:1-34.’ to see if these in-situ data can be applied for comparisons at this region. On the other hand, it seems that there are also in-situ soil moisture measurements at a national network of Chinese Automatic Soil Moisture Observation Stations (CASMOS) maintained by the Chinese Meteorological Administration (please see the information mentioned in https://hess.copernicus.org/preprints/hess-2020-407/), the author may also check the possibility of selecting some data to compensate comparisons. In case not lengthen the paper, comparisons can be attached as supplementary materials.

2. In Line 250, the author mentioned that 125 soil moisture stations (0-10cm) were used. Since AMSR2 are C-band (wavelength ~5 cm) sensors, meaning low penetration depth, even for SMAP L-band (wavelength ~21 cm), it can only detect changes of soil moisture in the top 0-5 cm (see F. T. Ulaby, R. K. Moore, and A. K. Fung, Microwave Remote Sensing, Active and Passive, Vol. III: From Theory to Applications. Norwood, MA: Artech House, 1986). The reviewer wonders why the author did not use 0-5 cm soil moisture measurements for comparisons. Unless the author provides the rationality, otherwise the review would suggest to use soil moisture measured at 0-5 cm for comparisons.

3. The review also suggests to make the code of the 3-D CCN network model available with the published paper.

Minor comments:
1. Please the author may complete the title as “Generating Seamless Global Daily AMSR2 Soil Moisture (SGD-SM) Long-term Products for the years 2013-2019”.

2. In Line 19, please give the full name when it (i.e., EOS) is first mentioned.

3. In Line 22, please add 'see Figure 1a.' for clarity in ‘about 30%~80% missing ratio in AMSR2)’.

4. In Line 143, please add ‘detailed technique descriptions of the network implementation are provided in the supplementary materials’ to guide the audience to see the supplementary.

5. In Line 221, please delete ‘It should be highlighted that’.

6. Please explain ‘COSMOS’ in Figure 7 and give the WGS84 geographical latitude and longitude for these sites shown in the figure title.

Hide

RR by Anonymous Referee #4 (26 Feb 2021)

ED: Publish subject to minor revisions (review by editor) (27 Feb 2021) by Giulio G.R. Iovine

AR by Qiang Zhang on behalf of the Authors (01 Mar 2021) Author's response Author's tracked changes Manuscript

ED: Publish as is (01 Mar 2021) by Giulio G.R. Iovine

AR by Qiang Zhang on behalf of the Authors (02 Mar 2021) Manuscript

Short summary

Acquired daily soil moisture products are always incomplete globally (just about 30 %–80 % coverage ratio) due to the satellite orbit coverage and the limitations of soil moisture retrieval algorithms. To solve this inevitable problem, we generate long-term seamless global daily (SGD) AMSR2 soil moisture productions from 2013 to 2019. These productions are significant for full-coverage global daily hydrologic monitoring, rather than averaging as the monthly–quarter–yearly results.