Scheduled Downtime
On Tuesday 24 October 2023 @ 5pm MT the forums will be in read only mode in preparation for the downtime. On Wednesday 25 October 2023 @ 5am MT, this website will be down for maintenance and expected to return online later in the morning.
Normal Operations
The forums are back online with normal operations. If you notice any issues or errors related to the forums, please reach out to help@ucar.edu

modify the met_data_file

S

snowyang1988@gmail_com

New Member
Hi,
Using the FSDW to simulate 2011-2013, I modify the data files in user_nl_cam. If I set the start time is 2011-01-01, I download the 2011-01-01 ncdata and modify user_nl_cam:

ncdata ="$DIN_LOC_ROOT/atm/waccm/ic/wa4_cesm1_1_b02_geos5_2x_sim153f.cam2.i.2011-01-01-00000.nc"

But I did not find the 2011 met_data on the subversion inputdata repository.There is only for 2005,2008,2010. So I don't know how tu modify the met data:

met_data_file=' '
met_data_path=' '
met_filenames_list=' '

Or need I simulate from 2010-01-01 ?

Jeff
 
Last edited by a moderator:
mmills

mmills

CSEG and Liaisons
Staff member
Jeff,The GEOS5 and MERRA met fields are distributed by NASA Goddard. You can get them from their data portal. NCAR does not redistribute them on our subversion repository. 
 
S

snowyang1988@gmail_com

New Member
Hi Simone and Mike,
Thank you for your help.
Which method of data assimilation does the FSDW use in nudging the winds and temperature with the met_data?
Another question:Before ago, I found the level num in the GEOS5/2005 is 72, but the num in FSDW is 88. How did it wok?
Jeff
 
Last edited by a moderator:
mmills

mmills

CSEG and Liaisons
Staff member
The data assimilation method used in SD-WACCM is described in Kunz et al. (2011):

In this study, a “nudging” approach is used where the simulated meteorological fields, Msim, are calculated in the following manner:

Msim = Mgeos * alpha + (1- alpha) * Mint

Mint and Mgeos are the meteorological fields from the interactive model and GEOS‐5, respectively. The fraction alpha of Mgeos used in this study is 0.01 (i.e., 1% of the Msim fields are from GEOS‐5). This “nudging” approach is applied at every model time step (i.e., every 30 min). For the meteorological fields this nudging scheme is applied from the surface to 50 km; above 60 km the model meteorological fields are fully interactive, with a linear transition in between. The vertical transport is derived from the divergence of the Msim horizontal winds. Even with a small fraction of the GEOS‐5 meteorological used at every time step, the resulting Msim fields accurately represent the original GEOS‐5 meteorological fields.

Kunz, A., L. L. Pan, P. Konopka, D. E. Kinnison, and S. Tilmes (2011), Chemical and dynamical discontinuity at the extratropical tropopause based on START08 and WACCM analyses, Journal of Geophysical Research[/i], 116[/i](D24), D24302, doi:10.1029/2011JD016686.

The nudging factor can be adjusted with a namelist variable, met_max_rlx, which can be set, for example, to 0.01 for 1% nudging per timestep, or 0.1 for 10% nudging.

See also:
Lamarque, J.-F., et al. (2012), CAM-chem: Description and evaluation of interactive atmospheric chemistry in the Community Earth System Model, Geosci. Model Dev., 5, 369–411, doi:10.5194/gmd-5-369-2012.
Wegner, T., D. E. Kinnison, R. R. Garcia, and S. Solomon (2013), Simulation of polar stratospheric clouds in the specified dynamics version of the whole atmosphere community climate model, J Geophys Res-Atmos[/i], 118[/i](10), 4991–5002, doi:10.1002/jgrd.50415.
 
Last edited by a moderator:
S

snowyang1988@gmail_com

New Member
Hi Mike,I want to generate the met file using ERA data and GFS. I have some question about the variables in the met file.

1)SOILW, soil moisture fraction. I find the data has soilw0_10cm, soilw10_40cm,soilw40_100cm and soilw100_200cm in the GFS data. Also, the ERA has volunetric soil water layer 1,2,3,4. How to calculate the SOILW in metdata?
2)ORO, can I use the value of GEOS5 when I use the GFS?
3)what 's the SGH and SGH30? I didnot get their meaning. I didnot find them in GFS data. The ERA has Standard deviation of orography and Standard deviation of filtered subgrid orography.

Regards.
Junfeng
 
Last edited by a moderator:
mmills

mmills

CSEG and Liaisons
Staff member
NCAR does not support ECMWF met fields. We provide support for GEOS5 and MERRA. You may look at those as examples if you want to try hooking up ECMWF yourself.
 
S

snowyang1988@gmail_com

New Member
Hi ,I have run the SD-WACCM with GEOS-5. I have 2 questions.1, The nudging approach is applied at every 6 hours (default), so the output at 0,6,12,18 o‘clock，is the model predictive field (before nudging)? or the analysis field (after nudging)?2, what’s the difference between SD and SC component. If I concentrate in winds/temperature, which I should use. thanks very much.jeff
 
mmills

mmills

CSEG and Liaisons
Staff member
Jeff,

Sorry for the delayed reply. See here:
bb.cgd.ucar.edu

Nudging approach in SD-WACCM

Hi everyone,I have run the SD-WACCM with GEOS-5. I have 2 questions.1, The nudging approach is applied at every 6 hours (default), so the output at 0,6,12,18 o‘clock，is the model predictive field (before nudging)? or the analysis field (after nudging)?2, What’s the difference between SD and SC...
bb.cgd.ucar.edu bb.cgd.ucar.edu

Mike
 
Last edited by a moderator:
X

xuexh@ustc_edu_cn

New Member
Hi Junfeng,    Have you successively run the SD-WACCM for the year 2011?   How do you solve the problem that the GOES input data was only available for January of 2005, January of 2008 and 2010?   
 
T

tilmes

Member
running with specified meteorological data, you will have to specify the following namelist variables, the directory path has to be adjusted to your location

bnd_topo = '/glade/p/cesm/cseg//inputdata/atm/cam/met/USGS-gtopo30_1.9x2.5_phys_geos5_c100929.nc' ; needs to be changed if using MERRA! ncdata ...

&metdata_nl
met_data_file = '2011/GEOS5.1_19x2_20110101.nc'
met_data_path = '/glade/p/cesmdata/cseg/inputdata/atm/cam/met/GEOS5' ; This is the location of the GEOS5 files
met_filenames_list = '/glade/p/cesmdata/cseg/inputdata/atm/cam/met/GEOS5/filenames_list.txt' ; create a filename_list.txt file that points to the GEOS5 data
met_max_rlx = 0.10 ; nudging factor
/


further, in env_build.xml make sure this is set:
Code: 
<entry id="CALENDAR"   value="GREGORIAN"  />
<entry id="CAM_CONFIG_OPTS"   value="-phys ... -chem ...  -nlev 88 -offline_dyn"  />    ; nlev is 56 if running CAM, 88 for WACCM

Location on the ESG for meteorological files to download:

Dataset: CCSM run merra.19x2, Atmosphere Forcing Data, 6-Hourly Instantaneous Values, version 1

www.earthsystemgrid.org www.earthsystemgrid.org

Simone
 
Last edited by a moderator:
You must log in or register to reply here.
Top