Dear all:
I have some trouble and confusion in running iCESM1.2 and iCESM1.3, some of them maybe detailed issues and others are general, which followd below.
1. The currently publicly available version on GitHub is iCESM1.2. However, when I test it by setting 'init_wiso_option' to 'file' and providing initial NetCDF format files for Delta18O and DeltaD (I'm not sure if R18O needs to be given), it seems that the ocean's log file does indeed read this file, but the output for Delta18O and DeltaD are NaN. Also, in 'namelist_definition_pop2.xml', it says '(this option does not work)'. I'm wondering if there's a way to resolve this issue, or is it possible to use a hybrid run and then change the current and old timestep seawater isotope distribution in the restart files? By the way, how long will water isotopes spin up for the upper and deep ocean if the seawater oxygen isotope initial condition is far away from the equilibrium, and if we have some spin up variables such as wind field, atmosphere and sea surface temperature from previous paleoclimate case, and take them for the IC or replace the restart files with previous spin up case, will it accelerate the water isotope spin up?
2. iCESM1.2 now includes abiotic 14C and neodymium isotopes. iCESM1.3 has a more comprehensive range of isotopes, including biotic δ13C and △14C as well as Pa/Th, but these are limited to the ocean module. It seems that carbon isotopes are also included in the CLM4.5 and LPX-Bern models, but there doesn’t seem to be a fully coupled CESM carbon isotope model released yet, right?
3. Compared with iCESM1.2, there is not much information related to iCESM1.3, are there significant differences between CESM1.2.2 and CESM1.3? It failed when I attempted to run iCESM1.3 with water isotopes, which says 'MCT::m_AttrVect::indexRA_:: FATAL--attribute not found: "Sl_qref_16O" Traceback: |X|MCT::m_AttrVect::indexRA_' in cesm.log, is there any difference between running iCESM1.2 and iCESM1.3 with water isotopes? And I wonder if running iCESM1.3 requires providing a land surface initial file containing isotopes, just like iCESM1.2 does.
4. In iCESM1.2, the default 'wiso_use_nml_surf_vals' is set to '.true.', and 'surf_avg_d18o_const' can be set to a constant. Otherwise, it seems that the ocean surface oxygen isotope is calculated. May I ask what impact this option has on running a fully coupled experiment? Also, what is the meaning of the ocean surface isotope flux correction 'wiso_sflx_correction_18o'? If considering the injection of meltwater, it should be modifying 'LIMW_F' in a specific area, and if considering the positive bias of the average value of seawater isotopes during the LGM, does it mean increasing the oxygen isotope values at all grid points in the 'init_wiso_init_file'?
5. iCESM1.2 requires the use of CAM5, which unlike CAM4, does not set the solar constant directly through 'solar_const' but reads the solar spectrum from a file. How can we modify the solar constant when simulating a paleoclimate? Also, CAM5's atmospheric chemistry module is more refined and does not use a 'prescribed_aero_file' like CAM4. In paleoclimate simulations, a prescribed, globally uniform aerosol distribution is usually used. Can a prescribed aerosol distribution also be set in CAM5?
I am grateful to any relevant answers or solutions in solving these problems!
I have some trouble and confusion in running iCESM1.2 and iCESM1.3, some of them maybe detailed issues and others are general, which followd below.
1. The currently publicly available version on GitHub is iCESM1.2. However, when I test it by setting 'init_wiso_option' to 'file' and providing initial NetCDF format files for Delta18O and DeltaD (I'm not sure if R18O needs to be given), it seems that the ocean's log file does indeed read this file, but the output for Delta18O and DeltaD are NaN. Also, in 'namelist_definition_pop2.xml', it says '(this option does not work)'. I'm wondering if there's a way to resolve this issue, or is it possible to use a hybrid run and then change the current and old timestep seawater isotope distribution in the restart files? By the way, how long will water isotopes spin up for the upper and deep ocean if the seawater oxygen isotope initial condition is far away from the equilibrium, and if we have some spin up variables such as wind field, atmosphere and sea surface temperature from previous paleoclimate case, and take them for the IC or replace the restart files with previous spin up case, will it accelerate the water isotope spin up?
2. iCESM1.2 now includes abiotic 14C and neodymium isotopes. iCESM1.3 has a more comprehensive range of isotopes, including biotic δ13C and △14C as well as Pa/Th, but these are limited to the ocean module. It seems that carbon isotopes are also included in the CLM4.5 and LPX-Bern models, but there doesn’t seem to be a fully coupled CESM carbon isotope model released yet, right?
3. Compared with iCESM1.2, there is not much information related to iCESM1.3, are there significant differences between CESM1.2.2 and CESM1.3? It failed when I attempted to run iCESM1.3 with water isotopes, which says 'MCT::m_AttrVect::indexRA_:: FATAL--attribute not found: "Sl_qref_16O" Traceback: |X|MCT::m_AttrVect::indexRA_' in cesm.log, is there any difference between running iCESM1.2 and iCESM1.3 with water isotopes? And I wonder if running iCESM1.3 requires providing a land surface initial file containing isotopes, just like iCESM1.2 does.
4. In iCESM1.2, the default 'wiso_use_nml_surf_vals' is set to '.true.', and 'surf_avg_d18o_const' can be set to a constant. Otherwise, it seems that the ocean surface oxygen isotope is calculated. May I ask what impact this option has on running a fully coupled experiment? Also, what is the meaning of the ocean surface isotope flux correction 'wiso_sflx_correction_18o'? If considering the injection of meltwater, it should be modifying 'LIMW_F' in a specific area, and if considering the positive bias of the average value of seawater isotopes during the LGM, does it mean increasing the oxygen isotope values at all grid points in the 'init_wiso_init_file'?
5. iCESM1.2 requires the use of CAM5, which unlike CAM4, does not set the solar constant directly through 'solar_const' but reads the solar spectrum from a file. How can we modify the solar constant when simulating a paleoclimate? Also, CAM5's atmospheric chemistry module is more refined and does not use a 'prescribed_aero_file' like CAM4. In paleoclimate simulations, a prescribed, globally uniform aerosol distribution is usually used. Can a prescribed aerosol distribution also be set in CAM5?
I am grateful to any relevant answers or solutions in solving these problems!