The efficient urban canopy dependency parametrization (SURY) v1.0 for
atmospheric modelling: description and application with the COSMO-CLM model
for a Belgian summer

Wouters, Hendrik; Demuzere, Matthias; Blahak, Ulrich; Fortuniak, Krzysztof; Maiheu, Bino; Camps, Johan; Tielemans, Daniël; van Lipzig, Nicole P. M.

doi:https://doi.org/10.5194/gmd-9-3027-2016

Articles | Volume 9, issue 9

https://doi.org/10.5194/gmd-9-3027-2016

© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/gmd-9-3027-2016

© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 9, issue 9

Development and technical paper

|

02 Sep 2016

Development and technical paper |

| 02 Sep 2016

The efficient urban canopy dependency parametrization (SURY) v1.0 for atmospheric modelling: description and application with the COSMO-CLM model for a Belgian summer

Hendrik Wouters, Matthias Demuzere, Ulrich Blahak, Krzysztof Fortuniak, Bino Maiheu, Johan Camps, Daniël Tielemans, and Nicole P. M. van Lipzig

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Final revised paper (published on 02 Sep 2016)
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Preprint (discussion started on 12 Apr 2016)
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Interactive discussion

Status: closed

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

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SC1: 'Executive Editor Comment on "Efficient urban canopy parametrization for atmospheric modelling: description and application with the COSMO-CLM model (version 5.0_clm6) for a Belgian Summer"', Astrid Kerkweg, 13 Apr 2016
- AC7: 'reply to the chief editor's comment', Hendrik Wouters, 22 Jun 2016
RC1: 'Major revision', Chunlei Meng, 13 Apr 2016
- AC1: 'Answers to comments of Chunlei Meng', Hendrik Wouters, 02 May 2016
- AC6: 'supplementary replies on the review of Dr. Chunlei Meng', Hendrik Wouters, 22 Jun 2016
RC2: 'Review of the paper by Wouters et al.', Anonymous Referee #2, 25 May 2016
- AC4: 'reply to the comments of reviewer 2', Hendrik Wouters, 22 Jun 2016
RC3: 'Review of Wouters et al', Anonymous Referee #3, 27 May 2016
- AC5: 'reply to the comments of reviewer 3', Hendrik Wouters, 22 Jun 2016
AC2: 'Revised manuscript with track changes', Hendrik Wouters, 22 Jun 2016
AC3: 'Revised manuscript without track changes', Hendrik Wouters, 22 Jun 2016

Peer-review completion

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

AR by Hendrik Wouters on behalf of the Authors (23 Jun 2016) Author's response Manuscript

ED: Referee Nomination & Report Request started (24 Jun 2016) by Min-Hui Lo

RR by Anonymous Referee #2 (04 Jul 2016)

RR by Anonymous Referee #4 (20 Jul 2016)

RR by Yi-Ying Chen (21 Jul 2016)

Suggestions for revision or reasons for rejection

Overall, the authors present a detail model description of SURY and it would be useful for utilizing the urban canopy within climate models with a better representation of land-atmosphere energy exchanges, which improves the capability of climate models or regional weather models to capture the heat island observation. This manuscript also demonstrated that the model can reproduced both SUHI and CLUHI at two selected sites in Belgium, and the work can be extend to the global scale when the global urban dataset from WUDAPT.org is ready. I suppose that this manuscript can be published in GMD library. However, I found a few minor issues which might need to be addressed. Below please see my comments on this manuscript.

General comment:
My primary concerns with this manuscript are the way that SURY applied for resolving the surface temperature (top layer soil temperature) and the physical representation of the rainfall interception loss within the urban-canopy model.
For my first concern, SURY re-parameterized the surface characteristic of urban land-cover by making use of a bulk approximation within an existing canopy model, which is based on a signal layer “Big-leaf” assumption. Thus, the physical representation of the surface temperature of the Eq. (1) can be treated as a lump land surface temperature for several tiles including imperious surface, canopy cover, bare soil or grass land. Under this assumption, we might be able to apply the surface energy balance equation to resolve the surface temperature (top layer soil temperature) for different land covers in a modeled grid. Thus, different land-cover tiles share the same surface temperature, which causes the difficulty to validate the model calculated land surface temperature.
Apart from the issue of validating the model predicted land surface temperature, the bulk surface heat conductivity (λbulk,s) was parameterized through a linear approximation by multiplying the original soil heat conductance (λs) with the SAI value (see Eq. (9)). But, in fact, the λs itself is a function of the top layer soil moisture content. In other words, the physical characteristic for the building is somewhat likes a permeable surface layer. Is this assumption reasonable?
Besides, I was confused about the way for solving land surface temperature (top layer soil surface temperature) in the TERRA_URB/SURY. Does the model incorporate the anthropogenic heat emission to the surface energy budget to resolve the surface temperature? Or it’s just a simple source or sink term in the surface energy budget and the land surface received the feedback energy from incoming long-wave radiation.

For the second comment, canopy can intercept 15% to 85% of total precipitation and can produce a substantial fast feedback to the atmospheric rainfall. SURY used a bulk average building height (H) to re-parameterize the original surface roughness (z0 in Eq. (7)). I can’t find the any equation/information regarding to the parameterization of the urban-canopy interception (Eimp) in the manuscript. The authors selected a drying period (sunny days) to test the newly proposed parameterization approach (SURY) may not have any impact on the result of the model simulation by making use of the current model configuration. However, the heat island effect can trigger or reinforce the afternoon thunderstorm events. Therefore, it is necessary to improve the physical representation of water budget in the urban-canopy model. I suggest that the authors improve the model description regarding to the urban-canopy water budget (see Eq. A12), the works on re-parametrization of the wet urban-canopy interception loss (Eimp in Eqs. (A6 and A12) will be appreciated. Besides, evaporative cooling effect from the urban-canopy loss can be studied or quantified. Anyway, the above issue seems outside the scope of this study, it will only become a substantial issue for large scale model simulations, such as long-term climate projections or weather predictions.

Specific comment:
P6L6 and P32L12:
Within the Eq. (1), the symbol T is the surface temperature. If this description is correct, the notation of “T” may have a conflict to the “T” in the Eq. (A7). Please make a change for the symbol of “T” in the Eq. (1) or Eq. (A7).
P7L3 and P32L31:
The definition of symbol “H” in the main context conflicts with the definition of symbol “H” in the appendix (see Eq. (A7)).
P32L32:
Please remove the empty space line in front of Eq. (A8)

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RR by Anonymous Referee #3 (01 Aug 2016)

ED: Publish subject to minor revisions (Editor review) (02 Aug 2016) by Min-Hui Lo

AR by Hendrik Wouters on behalf of the Authors (15 Aug 2016) Author's response Manuscript

ED: Publish as is (16 Aug 2016) by Min-Hui Lo

AR by Hendrik Wouters on behalf of the Authors (16 Aug 2016)

Short summary

A methodology is presented for translating three-dimensional information of urban areas into land-surface parameters that can be easily employed in atmospheric modelling. As demonstrated with the COSMO-CLM model for a Belgian summer, it enables them to represent urban heat islands and their dependency on urban design with a low computational cost. It allows for efficiently incorporating urban information systems (e.g., WUDAPT) into climate change assessment and numerical weather prediction.