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Requirements
Requirement: (1) update namelist options in the default compset; (2) update size distribution of dust emission fluxes; (3) update the dust emission distribution in the boundary layer
Date last modified: 2019-06-27
Contributors: Yan Feng
The first two updates have been implemented and tested in V1. The third update is implemented and tests are not completed.
Algorithmic Formulations, and Design Implementation
Design Solution:
(1) Change dust optics (dst_a1, dst_a3, dst_c1,dst_c3) in the namelist &cam_inpam to dust_aeronet_rrtmg_c141106.nc
(2) Change fractional emissions in size bins: dust_model.F90. The new dust emission size distribution is calculated based on Kok (2011). dust_emis_fact is updated for ne30 and ne120 to constrain the global dust optical depth to 0.026~0.03
Date last modified: 2019-06-27
Contributors: Yan Feng
Updated on 2020-05-28 by Yan Feng: updated the dust optics for RRTMGP to dust_aeronet_rrtmg_c141106.nc as well as mam1 and mam3 radiative properties used by RRTMGP
Planned Verification and Unit Testing
N/A
Planned Validation Testing
Validation Testing:
Implemented the new parameters and ran sensitivity simulations with V1. Evaluate the model outputs with observations
Date last modified: 2019-06-27
Contributors: Yan Feng
Table 1 list the model sensitivity studies and configurations. [updated by Yan Feng on 2020-05-28: global scaling factor is estimated from the simulations based on ERA40 reanalyses winds;
dust emissions are retuned for V2 using the model simulated winds, cf. /wiki/spaces/EWCG/pages/1045233888]
Horizontal resolution | Vertical layers | Physics configuration | Dust emission size distribution | SW optics | Global scaling factor | |
|---|---|---|---|---|---|---|
| LRes | ne30 | 72 | FC5AV1C-04P2 | Default (Zender et al., 2003) | Default | 2.05 |
| LResTN | ne30 | 72 | FC5AV1C-04P2 | Kok (2011) | AERONET | 0.95 |
| LResTNs | ne30 | 72 | FC5AV1C-H01A | Kok (2011) | AERONET | 0.95 |
| HResT | ne120 | 72 | FC5AV1C-H01A | Kok (2011) | AERONET | 1.2 (Default is 2.5) |
Model outputs
LRes is the control run with V1. Analyzed the last 5 years of the 11-year free model run (by Qi Tang). The model outputs are in:
| AERONET near source regions | LRes (Correlation with AERONET data) | LResTN | LResTNs | |
|---|---|---|---|---|
| AOD | 0.311 | 0.299 (0.91) | 0.284 (0.96) | 0.282 (0.97) |
| AAOD | 0.017 | 0.04 (0.69) | 0.022(0.72) | 0.022(0.74) |
| Dust AOD | Total | Accumulation | Coarse |
|---|---|---|---|
LRes | 0.026 | 0.0093 | 0.0171 |
LResTN | 0.026 | 0.0040 | 0.0214 |
LResTNs | 0.025 | 0.0040 | 0.0214 |
| HResT | 0.04 |
Kok, J. F. (2011). Does the size distribution of mineral dust aerosols depend on the wind speed at emission? Atmospheric Chemistry and Physics, 11(19), 10149-10156. <Go to ISI>://WOS:000296357300009
Kok, J. F., Ridley, D. A., Zhou, Q., Miller, R. L., Zhao, C., Heald, C. L., et al. (2017). Smaller desert dust cooling effect estimated from analysis of dust size and abundance. Nature Geoscience, 10(4), 274-278. <Go to ISI>://WOS:000398162800014
Zender, C. S., Bian, H. S., & Newman, D. (2003). Mineral Dust Entrainment and Deposition (DEAD) model: Description and 1990s dust climatology. Journal of Geophysical Research-Atmospheres, 108(D14). <Go to ISI>://WOS:000184611000001
Planned Performance Testing
No changes in performance