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

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, - competed, - in progress, - not done

Overview table for the owner and an approver of this feature

1.Description	Retuning of GWD to improve QBO
2.Owner	... ...
3.Created	Jun 25, 2019
4.Equ
5.Ver
6.Perf
7.Val
8.Approver
9.Approved Date
V2.0

Table of Contents

Title: Gravity Wave Modifications for Improved QBO

Requirements and Design

E3SM Group_name (for example Watercycle) Water Cycle

Date: Jul 8, 2019

Summary

The convective gravity wave (GW) source parameterization in large part controls the stratospheric quasi-biennial oscillation (QBO). In E3SM, v1 the QBO is too strong and too fast. We have made modifications to parameters in the GW parameterization that improve the representation of the QBO in terms of the period and amplitude.

Requirements

Requirement: Minor changes to source and namelist

Date last modified: Jul 8, 2019
Contributors: Wuyin Lin, Jadwiga Richter

Algorithmic Formulations

Design solution: All the code mods that are required are as follows:

in gw_convect.F90
real(r8), parameter :: CF = 12.5_r8

and in user_nl_cam
effgw_beres = 0.35

Date last modified: Jul 8, 2019
Contributors: Jadwiga Richter Chih-Chieh-Jack Chen Wuyin Lin

Design and Implementation

Implementation:
Transfer above parameters to code

Date last modified: Jul 8, 2019
Contributors: Jadwiga Richter Wuyin Lin

Planned Verification and Unit Testing

Verification and Unit Testing:

Date last modified: Jul 8, 2019
Contributors: Wuyin Lin

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:

30 yrs AMIP and coupled simulations: comparisons of QBO in simulations with above parameter changes in E3SMv1 (already ran and submitted for publication);

Evaluation of resolved wave spectra. Need to have daily means of: PRECT, OMEGA500, FLUT, U200, and U850 in output.

Date last modified: Jul 8, 2019
Contributors: Jadwiga Richter

Planned Performance Testing

Performance Testing:

Date last modified:
Contributors: Jadwiga Richter Wuyin Lin

Performance of the code should not be affected. Only parameter changes. Timings can be compared to previous runs.

W8 - Retuning of GWD to improve QBO Design Document