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ALBEDO calculation

S

seti

Member
Dear all,

I have a question about creating a new updated ALBEDO file using a MODIS product (MCD43A4). However, I read an article recently that used the same product to calculate the ALBEDO. This article pointed out that: "These albedos are directly implemented within the WRF model. We modified the model code to assign the measured pixel-level albedo to both pervious and impervious portions of each grid cell."

Now, I wonder what code should I modify? where is it? and how should I modify it?

I emailed the author of the paper, but he is on leave for about 1 month which is too long to wait!

The article is attached, and the statement could be fine on page number 7.
I will be happy if someone helps me.
Lind regards.
 

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Hi Seti,
I take a quick look at the paper as well as our repository code. It seems that the author implemented the Modis data to their own version of WRFv3.6.1, but I don't think these changes are included in official release of WPS.
In our WRF/WPS codes, monthly albedo and maximum snow albedo from MODIS can be used. Please see the website here. Detailed changes in the related codes can also be found in the website.
You can always refer to these changes when you attempt to add more data to WPS. Hope this is helpful for you.
 
Hi Ming,

Thanks for your explanation.
I meant that I want to use my own data (from MODIS in fact) instead of the one which is provided by the WRF community.
As far as I know, after converting the intermediate file (let's say new ALBEDO data) as an input file, GEOGRID.TBL file inside the WPS folder should be edited.
But in the article authors mentioned "We modified the code/codes", so I wonder which code/codes should be edited.
That was my question :)
Do you have any idea, please?
 
@Carly5 Hi. I did not receive any message from the authors. But I believe they changed the

"GEOGRID.TBL" , and also "geog_data_res".

Hope this help.
 
If the data in Geogrid Binary Format is available, then you only need to modify GEOGRID.TBL, which describes the features related to the data and how geogrid.exe should process the data (i.e., smooth_option, interp+option. etc.)

In namelist.wps, you need to specify source data to be used (in this case it should be your own Modis data).

With the above changes, you don't need to modify any source codes.

For the Geogrid Binary Format , please see WRF User's Guide at the website below: Chapter 3: WRF Standard Initialization)
 
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