W7 – ZM with unrestricted launch level (ULL) Design Document

Owned by Renata McCoy
Last updated: Jul 16, 2019 by Robert Jacob

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

 Click here for instructions to fill up the table below ......

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

  • Equations: Document the equations that are being solved and describe algorithms
  • Verification Plans: Define tests that will be run to show that implementation is correct and robust. Involve unit tests to cover range of inputs as well as benchmarks.
  • Performance expectations: Explain the expected performance impact from this development
  • Validation Plans: Document what process-based, stand-alone component, and coupled model runs will be performed, and with what metrics will be used to assess validity

Use the symbols below (copy and paste) to indicate if the section is in progress or done or not started.

In the table below 4.Equ means Equations and Algorithms, 5.Ver means Verification, 6.Perf - Performance, 7. Val - Validation,   (tick) - competed, (warning) - in progress, (error) - not done


Overview table for the owner and an approver of this feature

1.Description

ZM with unrestricted launch level (ULL)
2.OwnerShaocheng Xie
3.Created 
4.Equ(tick)
5.Ver(warning)
6.Perf(error)
7.Val(warning)
8.Approver
9.Approved Date
V2.0
 Click here for Table of Contents ...

Table of Contents




Title: Improved Convective Trigger for the ZM Deep Convection Scheme with the Unrestricted Launch Level (ULL) Method

Requirements and Design

E3SM Watercycle  Group

Date:  

Summary

The proposed convective trigger change is to primarily improve E3SM simulated diurnal cycle of precipitation by capturing nocturnal elevated convection through allowing air parcels to launch above boundary layer (BL) (Xie et al. 2019). The Unrestricted Launch Level (ULL) trigger works for searching the source layer, which is determined by the maximum static energy (MSE), for launching air parcel used in the calculation of cloud properties and rainfall intensity. In contrast to the assumption that the maximum MSE layer has to be in the boundary layer in ZM, the ULL trigger does the source layer search from surface to 600hPa. This allows for both surface-driven convection as the default ZM scheme does, and elevated convection that is initially decoupled from the surface.


Requirements

Requirement: Need minor code changes within ZM

Date last modified:  
Contributors: Shaocheng Xie, Wuyin Lin, Yi-Chi Wang


(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: In contrast to the assumption that the maximum MSE layer has to be in the boundary layer in the default ZM, the ULL trigger does the source layer search from surface to 600hPa. See more details in Xie et al. 2019.

Date last modified:  
Contributors:Shaocheng Xie, Yi-Chi Wang


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:

Pull requests incorporate the ULL trigger into E3SM v2: ?????? (@wuyin, please fill in the information)

Date last modified:  
Contributors: Wuyin Lin


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?


Planned Verification and Unit Testing 

Verification and Unit Testing:

A test mod directory was added as part of PR ????

Date last modified:  
Contributors: Wuyin Lin; Shaocheng Xie


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:

Comparison of experiments with ULL against EAMv1 control here (will provide a link to the test results here)

Xie et al. 2019 documented the comparison the ULL with the released EAMv1

Date last modified:
Contributors: Shaocheng Xie, Wuyin Lin


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?

Planned Performance Testing 

Performance Testing: short-desciption-of-testing-here (will do by the performance team)

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?