Implementation of sequential cropping into  JULESvn5.2 land-surface model

Mathison, Camilla; Challinor, Andrew J.; Deva, Chetan; Falloon, Pete; Garrigues, Sébastien; Moulin, Sophie; Williams, Karina; Wiltshire, Andy

doi:https://doi.org/10.5194/gmd-14-437-2021

Articles | Volume 14, issue 1

https://doi.org/10.5194/gmd-14-437-2021

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

Special issue:

https://doi.org/10.5194/gmd-14-437-2021

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

Articles | Volume 14, issue 1

Development and technical paper

|

25 Jan 2021

Development and technical paper |

| 25 Jan 2021

Implementation of sequential cropping into JULESvn5.2 land-surface model

Camilla Mathison, Andrew J. Challinor, Chetan Deva, Pete Falloon, Sébastien Garrigues, Sophie Moulin, Karina Williams, and Andy Wiltshire

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Final revised paper (published on 25 Jan 2021)
Preprint (discussion started on 25 Apr 2019)

Interactive discussion

Status: closed

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

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- Supplement

RC1: 'Review of Mathison et al.', Anonymous Referee #1, 30 May 2019
RC2: 'Review of Mathison et al.', Anonymous Referee #2, 18 Jun 2019
RC3: 'Review of Mathison et al.', Anonymous Referee #3, 18 Jun 2019
AC1: 'Authors response to reviewers comments', Camilla Mathison, 25 Jul 2019

Peer-review completion

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

AR by Camilla Mathison on behalf of the Authors (08 Oct 2019) Author's response Manuscript

ED: Referee Nomination & Report Request started (21 Oct 2019) by Wolfgang Kurtz

RR by Anonymous Referee #3 (16 Nov 2019)

RR by Anonymous Referee #1 (19 Nov 2019)

RR by Anonymous Referee #2 (25 Nov 2019)

Suggestions for revision or reasons for rejection

The revised manuscript is much better shaped than the original version and more in line with publication standards. In this revised version, many referee comments have been accounted for but a major comment was not: The absence of comparison of simulations with and without the sequential cropping. As mentioned in my first report, this is the only way to quantify the added value of representing the sequential cropping on a given variable or process. This would need the provision of simulations with a model configuration without the sequential cropping (ie with only one crop growing within a year), to be used as a reference. This remark has also been done by one of the two other referees of the original manuscript (“The authors show the model performance accounting sequential cropping, but how does it compare with the one not accounting sequential cropping? What will be the difference if simulating two seasons of crops as two tiles? Will the LAI be different? Will the yield? At least to this reviewer, the authors fail to prove the improvements brought to the land surface model”).
The authors replied to my comment by mentioning that “including sequential cropping in models is [...] a more realistic representation of the land surface in terms of land cover and therefore fluxes. And to the other referee by mentioning that “The very fact that the land surface is more representative of reality with two crops growing in sequence representing the real coverage of the land will produce more realistic fluxes and interactions with the atmosphere.” That is certainly true that the sequential cropping is more representative of reality (for regions where it is a common practice) but the “translation” into more realistic fluxes is rather an assumption which is stated in several places in the revised manuscript, for instance page 29 line 27.
I think it is needed to move from that assumption to a quantitative assessment of the impacts of the sequential cropping on the yield, lai, soil moisture, ... This could be done as a sensitivity study over the 4 Indian points and the Indian regions simulations.
To my opinion, the lack of this quantitative assessment is critical and detrimental to the present study.

Technical comments:

Page 3 line 15: Give the meaning of LPJ-ml here, not line 17. “Lund–Potsdam–Jena managed Land model (LPJml) is one of ...”

Eq 1: I’m surprised of the 2 temperature functions involved in the computation of Vcmax. What do they refer to ? Vcmax25 is not defined. I would assume it is the Vcmax value at 25°C but with the function [1+exp(0.3(Tc-Tupp)][1+exp(0.3(Tlow-Tc)], Vcmax does not equal Vcmax25 at 25°C. This is surprising.
Eq. 2: if Q1O equals 1 for all crops you consider in your study, it is maybe simpler to remove fT from equation 1 and to remove eq. 2.

Page 9 line 3 to 11: this information about parameterization should be moved page 5 where equation 3 is described (at least the information that there is no nitrogen cycle in your model).

Page 10 line 21: “the JULES”, remove “the”

Page 13 line 17: Need parenthesis for the citations of Monfreda et al. (2008) and Ramankutty et al. (2008).

Page 27 line 15: “very wet (500 mm of rain)”. Page 13 it is mentionned that annual precipitation is 680 mm. Could you clarify ?

Page 28 line 6 to 8: Delete “In the following section we apply this same method to a range of locations that use the sequential cropping system in the north of India in order to implement this method for a regional tropical simulation.”

Page 28 line 27: Delete “in these simulations”

Figure 10: X-axis is time in “day of year” not month

Figure 11: X-axis is time in “day of year” not month

Table 2: Add units to the parameters.

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ED: Reconsider after major revisions (02 Dec 2019) by Wolfgang Kurtz

AR by Camilla Mathison on behalf of the Authors (12 Jun 2020) Author's response Manuscript

ED: Referee Nomination & Report Request started (04 Jul 2020) by Wolfgang Kurtz

RR by Katharina Waha (06 Aug 2020)

RR by Anonymous Referee #3 (09 Aug 2020)

ED: Reconsider after major revisions (27 Aug 2020) by Wolfgang Kurtz

AR by Camilla Mathison on behalf of the Authors (06 Oct 2020) Author's response Manuscript

ED: Referee Nomination & Report Request started (22 Oct 2020) by Wolfgang Kurtz

ED: Publish as is (04 Dec 2020) by Wolfgang Kurtz

AR by Camilla Mathison on behalf of the Authors (07 Dec 2020)

Short summary

Sequential cropping (also known as multiple or double cropping) is a common cropping system, particularly in tropical regions. Typically, land surface models only simulate a single crop per year. To understand how sequential crops influence surface fluxes, we implement sequential cropping in JULES to simulate all the crops grown within a year at a given location in a seamless way. We demonstrate the method using a site in Avignon, four locations in India and a regional run for two Indian states.