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Question on substitution of ALB/LAI/GVF in WRF V4.0

This post was from a previous version of the WRF&MPAS-A Support Forum. New replies have been disabled and if you have follow up questions related to this post, then please start a new thread from the forum home page.


Dear WRF Community,

I have a question on substitution of ALB/LAI/GVF in WRF V4.0. As for these three, I can replace the equivalent fields through usemonalb = true, rdlai2d = true, and sst_update=1 in namelist.input.

Question 01: if sst_update = 0, usemonalb = false, rdlai2d = false in namelist.input, then:
we are using albedo from TBL, lai from TBL, but GVF (VEGFRAC) from monthly MODIS. This is verified from wrfout* files. Is there a control/switch for GVF (VEGFRAC) from TBL?

I found the following folders in static GEOG package, whose path one has to specify in namelist.wps for pre-processing.
/albedo_modis /lai_modis_10m /maxsnowalb_modis /greenfrac_fpar_modis /lai_modis_30s /modis_landuse_20class_30s_with_lakes

Question (a) LAI/albedo/VEGFRAC are originally derived from these binary static files?
Question (b) Where can I get the description or reference on the procedure of generating these fields from MODIS products? (one year MODIS product, might be 2006, is used? How the 8 day/16 day products are processed to generate monthly snow-free gap-filled LAI/albedo/VEGFRAC?)

Question 02: if I wish to substitute additional fields, such as emissivity, what should I do? The wrflowinp.d0*.nc files do not contain corresponding field. Specifically, I have other data to incorporate and wish to substitute the variable EMISS (surface emissivity). The WRF default surface emissivity seems to be derived from .TBL values, I assume.

Question 03: Noah-Unified is used as Land Surface Model. I wish to know what did WRF source code read wrflowinp* files to update LAI, albedo, VEGFRAC fields.

Thanks in advance.

Sorry to trouble you again. This has also been posted on:
As you mentioned, we are already addressing this problem here:

To prevent confusion, and from possibly having multiple people using their time/resources answering the same question, we ask that you please only post your question in 1 place. Please also note that we have many inquiries to address (that can each take a great amount of time to research), in addition to other responsibilities, and it can sometimes take a few days for us to be able to provide a response to each question. Thank you for your patience.
Thanks for the reply. I have already seen the answer.

Sorry to post the same topic twice. I will stick to the same page to avoid confusion. :)