This page should describe Verification and Unit Tests performed for this stand-alone feature and should provide links to all the result pages.

Summary

The new feature is tested with fully coupled E3SM simulation for both PI-control and historical layout.

Verification Test 1

Verification Test 1: Inter-comparison of two-stream shortwave radiative transfer models in E3SM

Date last modified: Jun 17, 2019

Contributors: Cheng Dang (Unlicensed)

Provenance: (Run provenance Link, Code Tag, etc.)

Results: 

1. Comparisons of three two-stream models (i.e., SNICAR used in ELM, dEdd-AD used in MPAS-seaice, and a new algorithm 2SD) against a 16-stream DISORT benchmark model show dEdd-AD produces more accurate snow radiative properties, especially under a cloudy sky. 

Figure 6 of Dang et al., 2019: Errors in diffuse snow albedo computed using the three two-stream models, for various snow depths and snow grain radii, with solar zenith angle of 60° at the top of the atmosphere.

2. Comparisons of different band setup show that the 5-band schemes used by SNICAR effectively captures the spectral variation of snow albedo and produces more accurate solar flux calculation for snow-covered sea ice. 

Verification Test 2

Verification Test 2: Correction for direct albedo for large solar zenith angles

Date last modified: Jun 17, 2019

Contributors: Cheng Dang (Unlicensed)

Provenance: (Run provenance Link, Code Tag, etc.)

Results: 

Figure 12 of Dang et al., 2019: Error in semi-infinite snow albedo computed using dEdd-AD before (top row) and after (bottom row) incorporating corrections for near-IR albedo, for different solar zenith angles and snow grain radii.

Reference: Dang, C., Zender, C. S., and Flanner, M. G.: Inter-comparison and improvement of 2-stream shortwave radiative transfer models for unified treatment of cryospheric surfaces in ESMs, The Cryosphere Discuss., https://doi.org/10.5194/tc-2019-22, in review, 2019.