Changes between Version 6 and Version 7 of Documentation/Frac_Nobio
- Timestamp:
- 2016-05-12T09:35:34+02:00 (8 years ago)
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Documentation/Frac_Nobio
v6 v7 3 3 4 4 5 frac_nobio is the variable which describes the fraction of the grid box which will never (in the foreseeable future !) be covered with vegetation. These fraction can be covered by glaciers, cities lakes or any other surface type where no biological activity (transpiration, assimilation, decomposition, ...) will happen.5 frac_nobio is the variable which describes the fraction of the grid box which will never (in the foreseeable future !) be covered by vegetation. These fraction can be covered by glaciers, cities lakes or any other surface type where no biological activity (transpiration, assimilation, decomposition, ...) will happen. For the moment only glaciers are considered. 6 6 7 This variable has 2 dimensions : kjpindex and nnobio, in other words the number of land grid points in ORCHIDEE and the number of no-bio classes. For the moment nnobio=1. 7 Thus the grid box within ORCHIDEE is devided into fractions of no-bio and veget with the following property : ''' 1 = SUM(frac_nobio(:,jn), jn=1,nnobio) + SUM(veget_max(:,jv), jv=1,nvm)''' 8 9 This variable has 2 dimensions : kjpindex and nnobio. In other words, the number of land grid points in ORCHIDEE and the number of no-bio classes. For the moment nnobio=1. 8 10 9 11 10 In the following we will go through each of the modules and detail where thefrac_nobio is used and with which intention.12 In the following we will go through each of the modules and detail where frac_nobio is used and with which intention. 11 13 12 14 == general comments == 13 15 14 the 2 variables frac_nobio and totfrac_nobio are passed to most subroutines and thus this is redundant information as in principle totfrac_nobio(:) = SUM(frac_nobio(:,jv), jv=1,nnobio) but nowhere is it verified that the this is indeed true.16 the 2 variables frac_nobio and totfrac_nobio are passed to most subroutines. This is redundant information as in principle totfrac_nobio(:) = SUM(frac_nobio(:,jn), jn=1,nnobio). Nowhere is it verified that the this is indeed true and in case of the DVGM activated it will certainly not be the case. 15 17 16 18 The addition of the second dimension to frac_nobio (nnobio) was not done correctly and is not fully implemented. 17 19 18 Thus a first step in an effort to better handle the no-bio fraction would be to clean-up the code and only use frac_nobio and deal properly with its second dimension.20 A first step in an effort to better handle the no-bio fraction would be to clean-up the code and terminate the implementation of the nnobio dimension. Only frac_nobio should be used and the implementation of the second dimension should be finished. 19 21 20 22 == slowproc == 21 23 22 slowproc_veget : computes the frac_nobio from the vegetation map read by summing all the fractions which are covered by ice, lakes, cities, ...24 slowproc_veget : computes the frac_nobio from the vegetation map read. It sums all the fractions which are covered by ice in carteveg5km.nc. 23 25 24 26 slowproc_readvegetmax : derived from the PFT map as the complement needed to bring the sum of veget(ig,jv) to 1. So the other types of non biological active surface types are apparently not documented in the PFT maps. … … 26 28 stomate_main : also returns a new total frac_nobio (totfrac_nobio_new) in case of a dynamic vegetation. 27 29 28 In case totfrac_nobio changes (which can occur through stomate_main) there is no code to adjust frac_nobio. 30 In case totfrac_nobio changes (which can occur through stomate_main) there is no code to adjust frac_nobio. Thus a divergence between these two variables will be created. 29 31 30 32 There is no code either to update all the prognostic variables of the model which depend on frac_nobio, does this matter ? … … 34 36 In condveg the frac_nobio is used in the same way as veget in order to derive surface properties. 35 37 36 condveg_snow : use dfrac_nobio to add the albedo of ice to the total albedo of the grid box. Should other nobio types be present the model will stop. So only frac_nobio for ice is foreseen for the moment.38 condveg_snow : uses frac_nobio to add the albedo of ice to the total albedo of the grid box. Should other nobio types be present the model will stop. So only frac_nobio for ice is foreseen for the moment. 37 39 38 40 condveg_z0logz and condveg_z0cdrag : use the same logic as for the snow and compute the grid box average surface roughness taking into account the properties of the ice (z0_nobio). … … 47 49 == enerbil == 48 50 49 Here frac_nobio is not used. The information about the fraction of the grid box which is not covered by vegetation or bare soil is integrated in the various surface parameters provided to enerbil (vbeta ?, soilflx, soilcap, ...).51 Here frac_nobio is not used. The information about the fraction of the grid box which is not covered by vegetation or bare soil is integrated in the various surface parameters provided to enerbil (vbeta1, soilflx, soilcap). 50 52 51 53 == hydrol == 52 54 53 hydrol_snow : frac_nobio is used to update the snow mass with the fraction of sublimation attributable to the fraction of the grid not covered by biological active surfaces. I lalso intervenes in the melting of the snow on (1-totfrac_nobio) and split the falling snow over the 2 sub areas of the grid box.55 hydrol_snow : frac_nobio is used to update the snow mass with the fraction of sublimation attributable to the fraction of the grid not covered by biological active surfaces. It also intervenes in the melting of the snow on (1-totfrac_nobio) and split the falling snow over the 2 sub areas of the grid box. 54 56 55 57 == thermosoil == … … 57 59 thermosoil_coef : frac_nobio is used in the computation of the effective soil heat capacity and heat flux by contributing soilcap_nosnow and soilflx_nosnow over its area. 58 60 59 '''Is this correct ?''' : The frac_nobio is to 61 '''Is this correct ?''' : The frac_nobio is today only ice and should thus be covered by snow or material of very similar properties. Thus frac_nobio should contribute to the effective soil heat capacity and heat flux snowcap and snowflux. This is directly related to the discussion started by Sylvie Charbit. 60 62 61 63 thermosoil_profile : frac_nobio is used to compute the effective surface temperature by combining the snow temperature (bottom of snow pack) an the surface temperature computed by
