Search found 29 matches

by Chang_Shu
Wed Jul 21, 2021 4:52 pm
Forum: geogrid
Topic: LAI12 and GREENFRAC in geo_em file v.s LAI and VEGFRA in wrfout file
Replies: 1
Views: 34

LAI12 and GREENFRAC in geo_em file v.s LAI and VEGFRA in wrfout file

Hello, WRF team I am doing research using WRF to analyze the relationship between urban heat islands and the urban vegetation/green area. I noticed there are two variables, LAI12 and GREENFRAC , in the geo_em file that might be related to the vegetation condition in the study region. I believe the L...
by Chang_Shu
Wed Jul 21, 2021 4:41 pm
Forum: wrf.exe
Topic: Long simulation time on some of the time-steps
Replies: 3
Views: 41

Re: Long simulation time on some of the time-steps

Hi, Ming I am using three nested domains with spatial resolutions of 9km, 3km and 1km My settings of radiation in my namelist.input is : mp_physics = 3, 3, 3 ra_lw_physics = 1, 1, 1 ra_sw_physics = 1, 1, 1 radt = 9, 3, 1 sf_sfclay_physics = 2, 2, 2 Would this be the problem? Thanks, Chang
by Chang_Shu
Tue Jul 13, 2021 6:09 pm
Forum: wrf.exe
Topic: Long simulation time on some of the time-steps
Replies: 3
Views: 41

Long simulation time on some of the time-steps

Hello, WRF team I am running a 1km resolution WRF run with 3 nested domains for a future time frame. I found that the simulation on some of the time-steps would take much longer time than most of the time-steps. Please find an example snippet below I found from the rsl.* files: Timing for main: time...
by Chang_Shu
Wed Jul 07, 2021 8:42 pm
Forum: geogrid
Topic: (RESOLVED) Does geo_em files related to the simulation time?
Replies: 2
Views: 49

Re: Does geo_em files related to the simulation time?

Thank you, kwerner.
I just noticed that some variables have 12 layers for 12 months.
Your answer helped me to confirm. Thanks.

Chang
by Chang_Shu
Mon Jul 05, 2021 6:39 pm
Forum: geogrid
Topic: (RESOLVED) Does geo_em files related to the simulation time?
Replies: 2
Views: 49

(RESOLVED) Does geo_em files related to the simulation time?

Hello, WRF team I am doing a multiple years WRF simulation, while due to the time limit for the jobs on our cluster, I have to split the whole long-term job into several smaller ones to simulate for one month in each simulation. I hope to reduce the preprocessing performed using the geogrid.exe, by ...
by Chang_Shu
Sun Jul 04, 2021 3:12 pm
Forum: geogrid
Topic: Difference Between LANDUSEF and FRC_URB2D?
Replies: 3
Views: 78

Re: Difference Between LANDUSEF and FRC_URB2D?

Thank you for the answer, kwerner

Just to confirm:
In LU_INDEX, number 13 is for urban and built-up land cover type. Then in LANDUSEF, the number array in the 13th layer should be the same as FRC_URB2D.
Please let me know if I am correct.

Thank you

Chang
by Chang_Shu
Mon Jun 21, 2021 4:34 pm
Forum: wrf.exe
Topic: SST update with nested domains
Replies: 6
Views: 102

Re: SST update with nested domains

longfei wrote:
Thu Jun 17, 2021 6:39 am
Problem solved, and stupid errors i made
thanks
Should it be SST_update = 1,1,1 to generate the wrflowinp file for all domains if using 3 domains?
by Chang_Shu
Mon Jun 21, 2021 2:34 pm
Forum: wrf.exe
Topic: (RESOLVED) 7-day and 7x1-day runs give rather different results
Replies: 3
Views: 168

Re: (RESOLVED) 7-day and 7x1-day runs give rather different results

Hello, WRF team

I found this resolved post because I am having a similar doubt.
And I would like to know which type of run is more suggested to obtain relatively more reliable results for the 7 days simulation? (1* 7 day run or 7 * 1 day run)

Thanks,

Chang
by Chang_Shu
Thu Jun 17, 2021 2:10 pm
Forum: geogrid
Topic: Difference Between LANDUSEF and FRC_URB2D?
Replies: 3
Views: 78

Difference Between LANDUSEF and FRC_URB2D?

Hello, wrf team I am wondering if there is any difference between the variable FRC_URB2D and the layer for urban land type in the variable LANDUSEF? As far as I know, LANDUSEF is to specify the fraction of each land cover type in different grid cells. So if summing up all the layers in this variable...
by Chang_Shu
Thu May 13, 2021 6:25 pm
Forum: metgrid
Topic: Read WRF Intermediate Format data files for analysis in Python or R
Replies: 1
Views: 425

Read WRF Intermediate Format data files for analysis in Python or R

Hello, I am wondering if anyone has ever dealt with the WRF Intermediate Format data files, which are for the input of the metgrid.exe program. I am doing future projections of the climate data using the NCAR CESM Global Bias-Corrected CMIP5 Output to Support WRF/MPAS Research dataset (https://rda.u...
by Chang_Shu
Sat Mar 13, 2021 5:23 pm
Forum: real.exe
Topic: calculate height of first model layer
Replies: 7
Views: 633

Re: calculate height of first model layer

Thank you, Ming. This solves my question. I am wondering is there any way to obtain the wind speed at 2m height? For this purpose, should I learn some similarity theory to infer the value at 2m by using the wind speed at 10m, I guess it should be related to a log-law or power-law profile derived by ...
by Chang_Shu
Thu Mar 11, 2021 1:56 am
Forum: real.exe
Topic: calculate height of first model layer
Replies: 7
Views: 633

Re: calculate height of first model layer

Hello, Ming I have a question regarding this one. As you have suggested that (PH + PHB)/9.8 gives the height of each level, can we estimate the height of the first layer grids by using the result of (PH + PHB)/9.8 for the first layer and subtract by HGT (terrain height level)? I am not quite sure ab...
by Chang_Shu
Tue Dec 01, 2020 5:22 am
Forum: WRF Physics
Topic: Calibration of urban parameter (URBPARM.TBL) and anthropogenic heat
Replies: 7
Views: 528

Re: Calibration of urban parameter (URBPARM.TBL) and anthropogenic heat

Thank you very much for the detailed answer.
So in my case, to reduce the wind speed prediction, I will try to only increase the Z0R in URBPARM.TBL and maybe also change the building height and street width percentage table to see if it can make the results better.

Chang
by Chang_Shu
Wed Nov 25, 2020 9:39 pm
Forum: wrf.exe
Topic: LU_INDEX changed in wrfout file
Replies: 4
Views: 286

Re: LU_INDEX changed in wrfout file

Understood. Thanks! Ming
by Chang_Shu
Wed Nov 25, 2020 9:28 pm
Forum: WRF Physics
Topic: Calibration of urban parameter (URBPARM.TBL) and anthropogenic heat
Replies: 7
Views: 528

Re: Calibration of urban parameter (URBPARM.TBL) and anthropogenic heat

Hello, Ming I have tested one case by increasing the lower boundary temperature for building surfaces. And the RMSE and MBE of T2 and precipitation come to be much better. But the wind speed is still not that good (MBE~+2.4 at multiple weather stations). So I am considering making changes to the rou...
by Chang_Shu
Wed Nov 25, 2020 4:49 pm
Forum: wrf.exe
Topic: LU_INDEX changed in wrfout file
Replies: 4
Views: 286

Re: LU_INDEX changed in wrfout file

Thanks, Ming I noticed that the results did not change much from the validation result. For multiple urban land classes, the LU_INDEX of 31, 32 and 33 have all been changed back to 13 in the wrfout file. Does that mean I have done anything wrong from my settings for multiple urban classes? Thanks, C...
by Chang_Shu
Tue Nov 24, 2020 10:44 am
Forum: wrf.exe
Topic: LU_INDEX changed in wrfout file
Replies: 4
Views: 286

LU_INDEX changed in wrfout file

Hello, WRF team I am using wps/3.9.1 and wrf/3.9.1.1 for a simulation using geog_data_res='default','default','default' in the namelist.wps file. input_from_file=.true.,.true.,.true., in the namelist.input file. The problem is that I found the LU_INDEX from the wrfout file is different from the LU_I...
by Chang_Shu
Tue Nov 24, 2020 6:36 am
Forum: WRF Physics
Topic: Calibration of urban parameter (URBPARM.TBL) and anthropogenic heat
Replies: 7
Views: 528

Re: Calibration of urban parameter (URBPARM.TBL) and anthropogenic heat

Thanks, Ming for the reply. I have noticed that anthropogenic heat is only available for the UCM model (sf_urban_physics=1), but I have just run a case with BEP model(sf_urban_physics=2) with AHOPTION and ALHOPTION =1 successfully. So I am wondering if the anthropogenic heat simulation is also compa...
by Chang_Shu
Mon Jun 29, 2020 4:43 pm
Forum: New/Modified Static Data
Topic: How to prepare the tiff file for gdal to generate the land cover binary files?
Replies: 3
Views: 865

Re: How to prepare the tiff file for gdal to generate the land cover binary files?

Hello, Duda I have tried to remap the tiff file to have assigned 13 to all the urban pixels, while changing all the others to 0. Then converted the tiff file to .bil using the command > gdal_translate -of ENVI foo.tif data.bil Then I changed the filename to the number of rows and cols following the ...
by Chang_Shu
Tue Jun 23, 2020 8:40 pm
Forum: New/Modified Static Data
Topic: How to prepare the tiff file for gdal to generate the land cover binary files?
Replies: 3
Views: 865

Re: How to prepare the tiff file for gdal to generate the land cover binary files?

Hello, Mr. Duda Thanks for your detailed reply. I will first remap the numbers in my tiff file then convert it to binary directly without cropping and coordination projections. Then let you know if it works. One thing is still kind of confusing for me is the category in the VEGPARM.TBL. For example ...
by Chang_Shu
Sat Jun 20, 2020 6:08 pm
Forum: New/Modified Static Data
Topic: How to prepare the tiff file for gdal to generate the land cover binary files?
Replies: 3
Views: 865

How to prepare the tiff file for gdal to generate the land cover binary files?

Hello, WRF team We are doing WRF simulations for several Canadian Cities like Ottawa, Montreal We are trying to update the urban land use land cover by extracting the urban pixels from a tif file for the input of WRF. I have noticed that in the WRF manual, it has mentioned to use the GDAL tool to tr...
by Chang_Shu
Fri Jun 19, 2020 3:59 am
Forum: geogrid
Topic: (RESOLVED) how to use the command "gdal_translate" when convert .tif into .bil?
Replies: 3
Views: 589

Re: how to use the command "gdal_translate" when convert .tif into .bil?

Hello, kwerner I have a question regarding this topic. I understand that we need gdal to convert the tif file to binary files. But how should we prepare the tif file: Should we take care of the coordinate projections in tif file? And how can we make sure the tif file is consistent with the existing ...
by Chang_Shu
Thu Mar 12, 2020 2:23 pm
Forum: wrf.exe
Topic: Land cover LU_INDEX changed after wrf.exe run --WRF V3.9.1.1
Replies: 4
Views: 565

Re: Land cover LU_INDEX changed after wrf.exe run --WRF V3.9.1.1

Hello,
I have tried to change surface_input_source = 3. But it did not work.

I changed the line
input_from_file = .true.,.false.,.false.,
to
input_from_file = .true.,.true.,.true.,

Then the result seems good!
Thanks for the help!

Chang
by Chang_Shu
Tue Mar 10, 2020 1:44 am
Forum: wrf.exe
Topic: Land cover LU_INDEX changed after wrf.exe run --WRF V3.9.1.1
Replies: 4
Views: 565

Re: Land cover LU_INDEX changed after wrf.exe run --WRF V3.9.1.1

Hello, kwerner
Thanks for your reply!
Please find the namelist.input in the attachment.
We are using NCEP North American Regional Reanalysis (NARR) ds608.0 as inputs.
by Chang_Shu
Mon Mar 09, 2020 9:34 pm
Forum: wrf.exe
Topic: Land cover LU_INDEX changed after wrf.exe run --WRF V3.9.1.1
Replies: 4
Views: 565

Land cover LU_INDEX changed after wrf.exe run --WRF V3.9.1.1

Hello, We are doing a 1 km resolution 3 domain nested simulation for the Ottawa area. However, we found the LU_INDEX in the WRF output file came to be large pixels, which is different from that in the geo_em.d03.nc and met_em.d03.*.nc files. Please find the plots for LU_INDEX in geo_em, met_em and w...

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