A13 Interactions With Surface Models - Aerosol Interactions with Ice Design Document
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
In the table below, 4.Equ means Equations and Algorithms, 5.Ver means Verification, 6.Perf - Performance, 7. Val - Validation, 
- completed, 
- in progress, 
- not done
Overview table for the owner and an approver of this feature
1.Description | Interactions with the surface models (soot and dust effects on ice albedo) |
| 2.Owner | |
| 3.Created | |
| 4.Equ | |
| 5.Ver | |
| 6.Perf | |
| 7.Val | |
| 8.Approver | |
| 9.Approved Date | |
| V1.0 | Accepted |
Title: Interactions with the surface models (light absorbing particles in snow/ice)
Requirements and Design
ACME Atmosphere Group
Date:
Summary
Requirements
modify the atmospheric aerosol deposition code to separately treat BC mixed internally within hydrometeors and externally to hydrometeors, and to partition dust into four size bins instead of two
modify the SNICAR code to take size-dependent BC optical properties (i.e., depending on snow grain size and BC particle size) and provide a new lookup table for the optical properties
modify the code in ALM for calculating snow grain size to fix an identified bug
Do the same to the sea ice component to take new size-dependent BC optical properties
Date last modified:
Contributors: Hailong Wang
(add your name to this list if it does not appear)
Algorithmic Formulations
Design solution: described in the following articles:
Date last modified:
Contributors: @Hailong Wang, Mark Flanner
Design and Implementation
Implementation:
Follow an initial implementation of most code changes to a developer version of CESM1.2 by Mark Flanner. The implementation has already been completed, but not in the B4B style, which will be modified soon.
Date last modified:
Contributors: Hailong Wang (add your name to this list if it does not appear)
Planned Verification and Unit Testing
Verification and Unit Testing
We will run tests to verify that the B4B with default model is maintained and the new implementation is consistent with that in the older version of CESM1.2.
Date last modified:
Contributors: Hailong Wang, Yun Qian, Mark Flanner (add your name to this list if it does not appear)
Planned Validation Testing
Validation Testing
Results of the ACME model with this new implementation will be validated against those in Flanner et al. (2012). Along with Polar Mods and other modifications in Aerosol/Clouds, BC-in-snow concentration and forcing will be evaluated against site measurements in field campaigns, like we did in Qian et al. (2014).
Qian Y., H. Wang, R. Zhang, M.G. Flanner, and P.J. Rasch, 2014: A sensitivity study on modeling black carbon in snow and its radiative forcing over the Arctic and Northern China. Environmental Research Letters, 9:064001.DOI:10.1088/1748-9326/9/6/064001.
Date last modified:
Contributors: Hailong Wang, Yun Qian, Mark Flanner
Planned Performance Testing
Performance Testing:
The new implementation is not expected to have significant impact on the computational cost/performance according to the implementation in an older version of CESM, but we will work with the performance team to get the new implementation in ACME fully tested.