Changes between Version 47 and Version 48 of DevelopmentActivities/ORCHIDEE-DOFOCO


Ignore:
Timestamp:
2013-02-05T11:22:14+01:00 (11 years ago)
Author:
mmcgrath
Comment:

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  • DevelopmentActivities/ORCHIDEE-DOFOCO

    v47 v48  
    1010         * The snow calculation has been modified to include snow in the background reflectance of Pinty's scheme, effectively putting snow under the canopy 
    1111         * Bernard's two stream solver routine has been modified to have both a diffuse and direct background reflectance value 
     12         * The snow albedo model of CLM3 has been incorporated, since it distinguishes between NIR and VIS light, as well as diffuse and direct 
     13         * All the albedo routines have been merged into the branch ORCHIDEE-DOFOCO 
    1214 
    1315== ROUTINES CHANGED == 
    … …  
    1921 
    2022== TO DO == 
    21         * Differentiate between infrared and visible scattering in the calculation of the snow albedo (MATT) 
    2223        * Confirm the details of the multi-layering scheme 
    2324        * change the dimensions of the variable albedo to store direct, diffuse, VIS and NIR (the direct and diffuse distinction becomes moot with the current multilayering scheme, as they must be averaged into one value for the background reflection to communicate between the layers) 
    … …  
    3738        * A 20 layer model was tested against the single layer model, giving small differences (a few percent, relative, at midday) 
    3839        * We tried to optimize the single scattering and forward efficiency values in the n-layer case to reproduce the average albedo in the 1-layer case, and using a generalised set search a full optimization with 20 layers can take thousands of steps and 200 times longer than doing no-optimization, and only a third of the points are optimised completely (for two layers, it takes about ten times longer than the no-opt case and optimises almost 70% of the timesteps)...using only 10-50 optimization steps results in 1-10% of the points being fully optimized, but looking at a graph of the two runs shows that the differences are really minimal, so we need to test the partial optimization in the new energy budget to see if it makes a real difference 
    39         * Inclusion of the new snow albedo gives realistic trends, with the total albedo spiking after snowfalls and showing diurnal variation with leaves are present, but being flat at other times (the solar angle is incorporated through the use of Pgap, which mostly depends on the canopy) 
     40        * Inclusion of the new snow albedo (CLM3) gives realistic trends, with the total albedo spiking after snowfalls and showing diurnal variation with leaves are present, but being flat at other times (the solar angle is incorporated through the use of Pgap, which mostly depends on the canopy) 
    4041        * I made use of single scattering albedos that Juliane got from Bernard's inversion scheme for 20 tree species, running tests with the min and max values for single scattering albedo and forward scattering efficiency for both VIS and NIR bands...the MUE for the overal albedo varies by 0.01 to 0.04 albdo units depending on the spectrum, showing that we should take this into account 
    4142