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Title: O_25_LI Land GLC Coupling Via CIME
Requirements and Design
ACME
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Ice-Ocean Group
Date: //date
Summary
The
purpose of this section is to summarize what capability is to be added to the ACME Ocean and Ice system through this design process. It should be clear what new code will do that the current code does not. Summarizing the primary challenges with respect to software design and implementation is also appropriate for this section. Finally, this statement should contain general statement with regard to what is “success.”
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. GLC model receives surface temperature and surface mass balance from the LND model. This coupling was implemented in CESM for CISM and is available to ACME via CIME. The CISM-CESM coupling also included liquid and solid runoff from the ice sheet model, which while not GLC-LND coupling is also considered here.
This functionality needs to be reproduced for MPASLI in ACME.
Requirements
The implementation of what CISM's GLC requires to work with the GLC-LND coupling in CIME can largely be seen in the GLAD modules created by Bill Sacks (Unlicensed) in CISM: https://github.com/ACME-Climate/cism-piscees/pull/35
Requirement: Fields from coupler to GLC
Date last modified: 2015/09/21
Contributors: Matt Hoffman, Bill Sacks (Unlicensed), Jeremy Fyke (Unlicensed), William Lipscomb (Unlicensed)
- qsmb - surface mass balance of glacier ice (kg/m^2/s)
- tsfc - surface ground temperature (deg C)
Starting with CIME, the coupler does downscaling so these fields are on the GLC grid.
In order for the coupler to return correct values of these fields, GLC must pass to the coupler gtopo and ice_covered. MJH: I'm guessing about this - is this correct?
Requirement: Fields from GLC to coupler
Date last modified: 2015/09/21
Contributors: Matt Hoffman, Bill Sacks (Unlicensed), Jeremy Fyke (Unlicensed), William Lipscomb (Unlicensed)
The GLC component needs to pass fields to the coupler:
- gtopo - surface elevation of each GLC grid cell (m)
- ice_covered - whether each grid cell is ice-covered [0,1]
- hflx - output heat flux (W/m^2, positive down) MJH: Is this at the ice sheet-atmosphere boundary?
- rofi - output ice runoff (kg/m^2/s = mm H2O/s) (This is not a LND coupling, but including it here as it also needs hooking-up.) MJH: This is sent to OCN model, correct?
- rofl - output liquid runoff (kg/m^2/s = mm H2O/s) (This is not a LND coupling, but including it here as it also needs hooking-up.) MJH: Is this sent to the ROF or the OCN model?
- ice_sheet_grid_mask - mask of ice sheet grid coverage MJH: how does this differ from "ice_covered"?
- icemask_coupled_fluxes - mask of ice sheet grid coverage where we are potentially sending non-zero fluxes MJH: is there a more complete description of what this means?
These fields need to be accumulated/averaged properly over the coupling interval by GLC. MJH: Which ones should be averaged vs. using a snapshot of the final time in the coupling interval?
Note that gtopo and ice_covered need to be updated in a TG run for qsmb, tsfc from the coupler to be correct (i.e., updated in time as the ice sheet evolves). However, those fields are not actually passed on to the LND model in an IG/BG run. In contrast, ice_covered is sent back to the LND model to determine where SMB calculations occur. MJH: I'm guessing about this - is this correct?
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.
(Not sure this section is necessary for this as this should be a relatively straightforward software engineering problem.)
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?(Leaving this partially blank for now until requirements are more fully understood. My intent is to get a TG case working first, than move to IG.)
Planned Verification and Unit Testing
Verification and Unit Testing: short-desciption-of-testing-here
Date last modified:
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?
Planned Validation Testing
Validation Testing:
short-desciption-of-testing-hereGLC-LND coupling
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
Date last modified:2015/09/21
Contributors:
(add your name to this list if it does not appear)Matt Hoffman, Jeremy Fyke (Unlicensed), William Lipscomb (Unlicensed)
Planned Performance Testing
Performance Testing: short-desciption-of-testing-here
Date last modified:
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?
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