the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 19 Jul 2024
The very-high resolution configuration of the EC-Earth global model for HighResMIP
Abstract. We here present the very-high resolution version of the EC-Earth global climate model, EC-Earth3P-VHR, developed for HighResMIP. The model features an atmospheric resolution of ~16 km and an oceanic resolution of 1/12° (~8 km), which makes it one of the finest combined resolutions ever used to complete historical and scenario-like CMIP6 simulations. To evaluate the influence of numerical resolution on the simulated climate, EC-Earth3P-VHR is compared with two configurations of the same model at lower resolution: the ~100-km-grid EC-Earth3P-LR, and the ~25-km-grid EC-Earth3P-HR. The models' biases are evaluated against observations over the period 1980–2014. Compared to LR and HR, VHR shows a reduced equatorial Pacific cold tongue bias, an improved Gulf Stream representation with a reduced coastal warm bias and a reduced subpolar North Atlantic cold bias, and more realistic orographic precipitation over mountain ranges. By contrast, VHR shows a larger warm bias and overly low sea ice extent over the Southern Ocean. Such biases in surface temperature have an impact on the atmospheric circulation aloft, with improved stormtrack over the North Atlantic, yet worsened stormtrack over the Southern Ocean compared to the lower resolution model versions. Other biases persist with increased resolution from LR to VHR, such as the warm bias over the tropical upwelling region and the associated cloud cover underestimation, and the precipitation excess over the tropical South Atlantic and North Pacific. VHR shows improved air–sea coupling over the tropical region, although it tends to overestimate the oceanic influence on the atmospheric variability at mid-latitudes compared to observations and LR and HR. Together, these results highlight the potential for improved simulated climate in key regions, such as the Gulf Stream and the Equator, when the atmospheric and oceanic resolutions are finer than 25 km in both the ocean and atmosphere. Thanks to its unprecedented resolution, EC-Earth3P-VHR offers a new opportunity to study climate variability and change of such areas on regional/local spatial scales, in line with regional climate models.
- Preprint
(10420 KB) - Metadata XML
- BibTeX
- EndNote
Status: open (until 13 Sep 2024)
-
RC1: 'Comment on gmd-2024-119', Thomas Rackow, 25 Jul 2024
reply
Review for "The very-high resolution configuration of the EC-Earth global model for HighResMIP”
by Moreno-Chamarro, Arsouze, Acosta, Bretonnière, Castrillo, Ferrer, Frigola, Kuznetsova, Martin-Martinez, Ortega, and Palomas
This is my first review for this paper. The authors present the EC-Earth3P-VHR model configuration, a high-resolution global climate model developed for HighResMIP, featuring atmospheric resolution of about 16km and 8km oceanic resolution. The model shows improvements in key regions like the Gulf Stream and the Equator compared to lower resolution models, with reduced biases in some areas but increased biases in others, such as a larger warm bias over the Southern Ocean. The model also demonstrates better air-sea coupling in tropical regions. However, it tends to overestimate the oceanic influence on atmospheric variability at mid-latitudes. Overall, the EC-Earth3P-VHR configuration appears to offer enhanced opportunities to study climate variability and change on regional and local scales.
First of all, the paper is in my view well-written, understandable, and has basically no typos. The figures are all high quality and well done. A description of the EC-Earth configuration for HighResMIP is clearly within the scope of GMD.
My only minor comments are with respect to highlighting some key results better, and better embedding the study into previous work, also outside of Europe. I have provided some references below for that purpose that the authors can decide to include at their convenience, and also gave suggestions for potential additional figures that could make the study even stronger. Overall, the study in its present form is already very interesting, it lists key results that are encouraging for fellow coupled high-res modellers, and is worthy of prompt publication. I am providing line-by-line comments below that I’d suggest having included before the paper can be accepted.#################################
Line-by-line comments:
l.59-60 I would suggest to cite relevant papers for these projects, for example Hoffmann et al. 2023 (https://doi.org/10.1016/j.cliser.2023.100394) for Destination Earth or Hohenegger et al. 2023 (https://doi.org/10.5194/gmd-16-779-2023 ) and Rackow et al. 2024 (already cited elsewhere in the study) for nextGEMS. There should be something from MetOffice for PRIMAVERA as well
l.64 have been “proven”
l.84 For single precision, there are other earlier examples, e.g. Váňa et al. 2017 (https://doi.org/10.1175/MWR-D-16-0228.1);
as Destination Earth and nextGEMS were listed, there is also Sarmany et al. 2024 (https://doi.org/10.1145/3659914.3659938) for IO considerations
l.91 Another extreme example next to Gutjahr et al. 2019 is AWI’s CMIP6 climate model (e.g. Rackow et al. 2019, https://doi.org/10.5194/gmd-12-2635-2019, Semmler et al. 2020 https://doi.org/10.1029/2019MS002009), where their ocean is locally finer than 10km and has been run with a 100km atmosphere. There might be other examples in CMIP
l. 104 Regarding “High-resolution modelling usually relies on single-model component”:
I think there are several examples for relatively high resolution in both components, e.g. Chang et al. 2020 (https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020MS002298), Small et al. 2014 https://opensky.ucar.edu/islandora/object/articles:14403, the high-res studies from the South Korean group (https://ibsclimate.org/research/ultra-high-resolution-climate-simulation-project/ and listed references there, e.g. https://www.science.org/doi/10.1126/sciadv.abd5109), and the DestinE, EERIE, PRIMAVERA and nextGEMS results of course as welll. 137 “of the” -> “of”
l. 138 Is this OpenIFS or IFS?
l. 161 240 s and 720 s has large white spacing
l. 198 What are the novel source code changes?
l. 200 Which model workflow software?
l. 204/205 Is there a parallel version of this available now? Is this linked as part of your document?
l. 209 Can you write technical details of “the network” here? Otherwise this does not tell much
l. 279-281 This inconsistency could trigger a bigger adjustment potentially. From your experience, does this lead to a cooling or warming initially that gets levelled out during the spinup?
l. 296 “but for” -> “except for”
l. 310 “will enjoy” please rephrase
l. 314/315 This is a very encouraging result; in principle, this is what modelling groups have been hoping for to see with higher resolution. This point could maybe be highlighted, potentially with a figure, and be included in the abstract?
l. 389 delete “bias” in this line?
l. 401 40 deg N seems far away from polar influence, are you sure about this statement?
Figure 13: Hard to see anything on those maps. Could you try with other colors or try a different (shorter) range?
l. 459/460 The plus/minus refers to what, standard deviation of monthly values?
l. 493-495 This seems like another key result that is very encouraging and not covered with a separate figure.
l. 535 Sections -> sections
l. 561 The lack of ocean current feedback comes a bit as a surprise here and could be covered earlier in the model description as to how the coupling is implemented
l. 580/581 Maybe give another example here if you know it (e.g. US or South Korean references mentioned above if matching), but this statement might indeed be correct
l. 585 excessive whitespace after “performed”
l. 619/620 Another study in this direction would be Sein et al. 2017 (https://doi.org/10.1002/2017MS001099). The authors argue that resolution over the shelf areas northward of the Gulf Stream front is key, an area where the cold Labrador water from the north meets the warm Gulf Stream water.
l. 687/688 “and VHR does it faster and appears more stable after 100 years than HR and LR” Another key result, see above
Citation: https://doi.org/10.5194/gmd-2024-119-RC1
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 290 | 80 | 12 | 382 | 14 | 8 |
- HTML: 290
- PDF: 80
- XML: 12
- Total: 382
- BibTeX: 14
- EndNote: 8
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1