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About the setting of inundation

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lucia

luyaohuang
Member
I have a question to ask everyone. I am simulating methane emissions from the Qinghai Tibet Plateau. My simulation accuracy is 0.1 degrees * 0.1 degrees. Regarding the calculation of inundation, I use the default setting of clm, finundation_method='TWS_inversion', and use the parameter finundated_inversiondata_0.9x1.25_c170706.nc to calculate the inundation ratio of the Qinghai Tibet Plateau and obtain methane fluxes. However, I found that the resolution of satellite inversion for this parameter is too coarse, and I cannot accurately simulate the inundation and wetland conditions of the Qinghai Tibet Plateau. Moreover, many of the methane emission areas I simulated do not match the measured absorption completely. Therefore, I think this method may not be applicable to the Qinghai Tibet Plateau. My setting is finding_method='h2osfc ', and I used the land use map to set frac_h2osfc (c)=1.0 for areas with wetlands in the grid. Then, I calibrated the model by adjusting parameters related to the methane flux process. The simulated values of the obtained model match well with the measured values. R ²= 0.7. I would like to inquire if this setting is reasonable. I directly set the inundation status of this place as completely submerged.
If anyone could answer my question, I would be extremely grateful
 
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oleson

Keith Oleson
CSEG and Liaisons
Staff member
I've checked with members of our group. This was the one response:

"It seems like they just forced the inundation fraction to 1 based on observed data. I don't know how to answer the question 'is it reasonable?' though. I think it is reasonable to turn off the tws-based method. The tws-method is just a diagnostic way to estimate the inundation, and there is no real physical connection between tws and inundation. I think it was just a convenient variable to use in the regression."

Unfortunately, we don't really have any other expertise in the methane model in our group. The model and code were contributed by an outside collaborator several years ago. Bill Riley and Zack Subin, as indicated in the technical note:


Riley, W. J., Z. M. Subin, D. M. Lawrence, S. C. Swenson, M. S. Torn, L. Meng, N. Mahowald, and P. Hess, 2011a. Barriers to predicting global terrestrial methane fluxes: Analyses using a methane biogeochemistry model integrated in CESM. Biogeosciences, 8, 1925–1953. DOI:10.5194/bg-8-1925-2011.
 
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