Submitted as: model description paper 17 Dec 2020
Submitted as: model description paper | 17 Dec 2020
SimCloud version 1.0: a simple diagnostic cloud scheme for idealized climate models
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
Abstract. SimCloud, a simple diagnostic cloud scheme for general circulation models (GCMs) is proposed in this study. The large-scale clouds, which form the core of the scheme, are diagnosed from relative humidity. In addition, marine low stratus clouds, typically found off the west coast of continents over subtropical oceans, are determined largely as a function of inversion strength. A freeze-dry
adjustment based on a simple function of relative humidity may also used to reduce an excessive clouds bias in polar regions. Other cloud properties, such as the effective radius of cloud droplet and cloud liquid water content, are specified as simple functions of temperature. All of these features are user-configurable. The cloud scheme is implemented in Isca, a modeling framework designed to enable the construction of GCMs at varying levels of complexity, but could readily be adapted to other GCMs. Simulations using the scheme with realistic continents generally capture the observed structure of cloud fraction and cloud radiative effect (CRE), as well as its seasonal variation. Specifically, the explicit low cloud scheme improves the simulation of shortwave CREs over the eastern subtropical oceans by increasing the cloud fraction and cloud water path over there. The freeze-dry adjustment alleviates the longwave CRE biases in polar regions especially in winter. However, the longwave CRE in tropical regions and shortwave CRE over extratropics are still too strong compared to observations. Nevertheless, this simple cloud scheme provides a suitable basis for examining the impacts of clouds on climate in idealized modeling frameworks.
- Preprint
(6094 KB) -
Supplement
(75 KB) - BibTeX
- EndNote
Qun Liu et al.


-
SC1: 'executive editor comment on gmd-2020-402', Astrid Kerkweg, 21 Dec 2020
-
SC2: 'Reply to the Executive Editor's Comments', Qun Liu, 21 Dec 2020
-
SC2: 'Reply to the Executive Editor's Comments', Qun Liu, 21 Dec 2020
-
RC1: 'The manuscript is well written and should be accepted after minor revisions.', Anonymous Referee #1, 07 Jan 2021
-
AC1: 'Short reply to reviewers', Qun Liu, 19 Jan 2021
-
AC1: 'Short reply to reviewers', Qun Liu, 19 Jan 2021
-
RC2: 'Review of Qun Liu et al.', Anonymous Referee #2, 18 Jan 2021
-
AC2: 'Short reply to reviewers', Qun Liu, 19 Jan 2021
-
AC2: 'Short reply to reviewers', Qun Liu, 19 Jan 2021


-
SC1: 'executive editor comment on gmd-2020-402', Astrid Kerkweg, 21 Dec 2020
-
SC2: 'Reply to the Executive Editor's Comments', Qun Liu, 21 Dec 2020
-
SC2: 'Reply to the Executive Editor's Comments', Qun Liu, 21 Dec 2020
-
RC1: 'The manuscript is well written and should be accepted after minor revisions.', Anonymous Referee #1, 07 Jan 2021
-
AC1: 'Short reply to reviewers', Qun Liu, 19 Jan 2021
-
AC1: 'Short reply to reviewers', Qun Liu, 19 Jan 2021
-
RC2: 'Review of Qun Liu et al.', Anonymous Referee #2, 18 Jan 2021
-
AC2: 'Short reply to reviewers', Qun Liu, 19 Jan 2021
-
AC2: 'Short reply to reviewers', Qun Liu, 19 Jan 2021
Qun Liu et al.
Data sets
Outputs from Isca simulations with simple cloud scheme and SOCRATES radiation scheme Qun Liu, Matthew Collins, Penelope Maher, Stephen Thomson, and Geoffrey Vallis https://doi.org/10.5281/zenodo.3831988
Model code and software
Cloud Scheme Manuscript Figures v1.0 Qun Liu https://doi.org/10.5281/zenodo.4319639
Qun Liu et al.
Viewed
HTML | XML | Total | Supplement | BibTeX | EndNote | |
---|---|---|---|---|---|---|
381 | 96 | 4 | 481 | 63 | 5 | 2 |
- HTML: 381
- PDF: 96
- XML: 4
- Total: 481
- Supplement: 63
- BibTeX: 5
- EndNote: 2
Viewed (geographical distribution)
Country | # | Views | % |
---|
Total: | 0 |
HTML: | 0 |
PDF: | 0 |
XML: | 0 |
- 1