The Design Document page provides a description of the algorithms, implementation and planned testing including unit, verification, validation and performance testing. Please read Step 1.3 Performance Expectations that explains feature documentation requirements from the performance group point of view.
Design Document
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The first table in Design Document gives overview of this document, from this info the Design Documents Overview page is automatically created. In the overview table below 4.Equ means Equations and Algorithms, 5.Ver means Verification, 6.Perf - Performance, 7. Val - Validation
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Title: SNICAR-AD Shortwave Radiation for Sea Ice and Land
Requirements and Design
E3SM Cryosphere Group
Date:
Summary
Requirements
Requirement: name-of-requirement-here
Date last modified: // date
Contributors: @ name (add your name to this list if it does not appear)
Each requirement is to be listed under a ”section” heading, as there will be a one-to-one correspondence between requirements, design, proposed imple- mentation and testing. Requirements should not discuss technical software issues, but rather focus on model capability. To the extent possible, require- ments should be relatively independent of each other, thus allowing a clean design solution, implementation and testing plan.Algorithmic Formulations
Design solution: short-description-of-proposed-solution-here
Date last modified:// date
Contributors: (add your name to this list if it does not appear)
For each requirement, there is a design solution that is intended to meet that requirement. Design solutions can include detailed technical discussions of PDEs, algorithms, solvers and similar, as well as technical discussion of performance issues. In general, this section should steer away from a detailed discussion of low-level software issues such as variable declarations, interfaces and sequencing.
Design and Implementation
Implementation: short-desciption-of-implementation-here
Date last modified: // date
Contributors: (add your name to this list if it does not appear)
This section should detail the plan for implementing the design solution for requirement XXX. In general, this section is software-centric with a focus on software implementation. Pseudo code is appropriate in this section. Links to actual source code are appropriate. Project management items, such as svn branches, timelines and staffing are also appropriate. How do we typeset pseudo code?remove the discrepancy of shortwave radiative transfer simulation for snowpacks on sea ice and on land in E3SM. We implement the radiative transfer scheme SNICAR-AD in the sea-ice component MPAS-seaice and the land component ELM for E3SM to predict consistent and improved shortwave radiative properties of snow-covered surfaces.ELM: modify the land shortwave code to include a subroutine that adopts the new radiative transfer algorithm.
MPAS-seaice: modify the sea-ice shortwave radiative transfer code to include a new subroutine that
- provides new input files for snow and ice optics adopted by ELM;
- expands the shortwave radiative calculation from three to five subdivided solar bands adopted by ELM;
- removes empirical adjustment for radiative-effective snow grain size;
- adopts a new algorithm to correct for the bias of near-infrared albedo and absorption when solar zenith angles are larger than 75 degrees.
Date last modified: Jun 1st, 2019
Contributors: Cheng Dang (Unlicensed) Charlie Zender
Algorithmic Formulations
Design solution: described in the following article
Dang, C., Zender, C. S., and Flanner, M. G.: Inter-comparison and improvement of 2-stream shortwave radiative transfer models for a unified treatment of cryospheric surfaces in ESMs, The Cryosphere Discuss., https://doi.org/10.5194/tc-2019-22, in review, 2019.
Date last modified: July 1st, 2019
Contributors: Cheng Dang (Unlicensed) Charlie Zender Mark Flanner
Design and Implementation
Implementation:
In the sea-ice and land shortwave code (ice_shortwace.F90, SnowSnicarMod.F90), we implemented SNICAR_AD that can be turned on/off by configuration toggles in the model namelists.
MPAS-source code: https://github.com/chengdang/MPAS-Model/tree/seaice/cdang_SnicarAD
ELM-source code: https://github.com/chengdang/E3SM/tree/chengdang/lnd/SNICAR_AD
Verification and Unit Testing:
short-desciption-of-testing-here- The offline radiative transfer model has been tested against a multi-stream benchmark model. (Dang, C., Zender, C. S., and Flanner, M. G.: Inter-comparison and improvement of 2-stream shortwave radiative transfer models for a unified treatment of cryospheric surfaces in ESMs, The Cryosphere Discuss., https://doi.org/10.5194/tc-2019-22, in review, 2019.)
Date last modified:
July 1st, 2019
Contributors:
(add your name to this list if it does not appear)How will XXX be tested? i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?
Cheng Dang (Unlicensed)
Planned Validation Testing
Validation Testing:
short-desciption-of-testing-here- The modified E3SM model is tested with Pi-Control configuration, against the released Deckv1b simulation (mpas-analysis, e3sm diagnostics, and land comparison carried by the developer)
- 30-year MPAS-analysis: https://portal.nersc.gov/project/m2833/cdang/30yr.mpas_analysis.m2m.SNICAR_AD_landseaice_vs_DECKv1b.piControl.ne30_oEC.edison/
- 30-year E3SM diagnostics: https://portal.nersc.gov/project/m2833/cdang/30yr.e3sm_diags.m2m.SNICAR_AD_landseaice.SNICAR_AD_seaice.ne30_oEC.edison/viewer/
Date last modified: July 1st, 2019
Contributors:
(add your name to this list if it does not appear)How will XXX be tested? What observational or other dataset will be used? i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?
Cheng Dang (Unlicensed)
Planned Performance Testing
Performance Testing:
short-desciption-of-testing-hereThe new implementation is not expected to have a significant impact on the computational cost/performance of E3SM.