How to download NCEP GFS data after 2015 using TRAIN?

[jayd...@gmail.com]

Dear David，

   The current TRAIN can only download the archived NCEP GFS data before 2015. Do you know how to download it after 2015? Thank you.

Best wishes,

Jie Dong

Wuhan University, Wuhan, China

[mehdidar...@gmail.com]

Hi Jie,

I hope it would be helpful:

1- After registration on https://rda.ucar.edu/
2- Go to the https://rda.ucar.edu/datasets/ds335.0/#!access
3- In the row ''GFS 0.5deg Global files'', select ''request access''
4- In the opened page, select ''Faceted Browse''
5- Set your time span and select your data based on the ''GFS_file.txt'' file created by Train
6- At the end of page tap on the request, then you will get an email with the download link of the requested data.

I downloaded the GFS data for 2017 from above websit.

Mehdi

[jayd...@gmail.com]

Hi Mehdi,

 

Thanks for you reply. The website you gave indeed includes the GFS 0.5deg Global files after 2015.

If I use get_GFS.csh script to download the files listed in FGS_files.txt before 2015, the downloaded file size, for example 2014/GFS_Global_0p5deg_20160401_0600_anl.grib2, is small, about 90 MB. However, if I followed your procedure to search the GFS data, then getting the files for download with big size of more than 6 GB (the screenshot Fig.1).

In addition, is it possible to modify the get_GFS.csh script to automatically download the GFS 0.5deg Global files from the website 'https://rda.ucar.edu/datasets/ds335.0/#!access'  ?

Best wishes,

Jie Dong

[mehdidar...@gmail.com]

Hi Jie,

Yes, you are right, the size of the files are huge, since you are downloading the whole data with all parameters. After processing the raw data using WRF&WPS software, you will have small files (netsdf files around 5MB for each) as input for TRAIN. So, you do not then need to keep the all raw files on your system.

After submitting your order/request, the website will give you two options for downloading your data: 1- manually one by one, and 2- give you a csh file that you can run it on your Linux system and all data will be downloaded automatically.

Cheers,

Mehdi

[jayd...@gmail.com]

Hi Mehdi,

Thanks. It is really a hard work to download hundreds of 6GB files. I will try to do it.

Could you give me some suggestions about the setup of following parameters in aps_wrf_files.m. Especially, how could I modify the these five parameters: parent_grid_ratio, i_parent_start,j_parent_start, e_w, e_sn ?

%%%--------------------------------%%%
%%%%%% CHANGES REQUIRED BY USER
max_dom = 2; % number of domains
dx = 25000;  % unit: meter
dy = 25000;
parent_grid_ratio =  [1  5];
i_parent_start    =  [1  10];
j_parent_start    =  [1  8];
e_we              = [30  76];
e_sn              = [35  111];
ref_lat           = 31.58; % the central lat of study area
ref_lon           = 103.42;% the central lon of study area
truelat1          = 30.0;
truelat2          = 60.0;
stand_lon         = 103.42;
map_proj          = 'lambert';
geog_data_path    = '/media/dj/PHD/WPS_GEOG';
geog_data_res     = '3s';

Best wishes,

Jie Dong

[mehdidar...@gmail.com]

Hi Jie,

You do not need to modify those parameters, just set your ref lon/lant and go ahead. Those parameters are related to WRF data processing itself and if you want to know more over them, you can refer to the WRF manual.

Cheers,

Mehdi

[jayd...@gmail.com]

Hi Mehdi,

 Got it. Thanks a lot! I am downloading the GFS files.

Best wishes,

Jie Dong