Hi,
Recently, I run an assimilation experiment of indirect soil nudging with Pleim-Xiu Land Surface Model in WRF3.9.1. The section fdda in namelist.input are shown below:
& fdda
grid_fdda = 1, 0, 0,
gfdda_inname = "wrffdda_d<domain>",
gfdda_interval_m = 360, 360, 360,
gfdda_end_h = 360, 240, 240,
io_form_gfdda = 2,
fgdt = 0, 0, 0,
if_no_pbl_nudging_uv = 0, 0, 0,
if_no_pbl_nudging_t = 1, 0, 0,
if_no_pbl_nudging_q = 1, 0, 0,
if_zfac_uv = 1, 0, 0,
k_zfac_uv = 10, 10, 10,
if_zfac_t = 0, 0, 0,
k_zfac_t = 10, 10, 10,
if_zfac_q = 0, 0, 0,
k_zfac_q = 10, 10, 10,
guv = 0.0000
gt = 0.0000
gq = 0.0000
if_ramping = 1,
dtramp_min = 60.0,
grid_sfdda = 1, 0, 0,
sgfdda_inname = "wrfsfdda_d<domain>"
sgfdda_interval_m = 180, 180,
sgfdda_end_h = 360, 2184,
io_form_sgfdda = 2,
guv_sfc = 0.0000, 0.0000,
gt_sfc = 0.0000, 0.0000,
gq_sfc = 0.0000, 0.0000,
rinblw = 250.,
pxlsm_soil_nudge = 1, 1, 1,
/
I set "guv, gt, gq,guv_sfc, gt_sfc and gq_sfc equal 0" because I just need the observation surface data in wrfsfdda_d<domain> file to do indirect soil nudging. The wrfsfdda_d<domain> file is created by Objective Analysis (OBSGRID) with "met_em*" files and Surface data files in NCEP BUFR format(http://rda.ucar.edu/datasets/ds461.0/). In the assimilation experiment, I just assimilate the soil moisture and twmperature of partial region of the Model simulation domain because I just want to investigate the impact of soil assimilation in partial region on the precipition in the whole Model simulation domain. Therefore, I wonder if the data in "met_em*" files influence the assimilation, or if the data in files "met_em*" are also assimilated by the file "wrfsfdda_d<domain>" file.
For my question, I have done some works. I compared 3 experiments: (1) no assimilation; (2) do OBSGRID with files "met_em*" and observation surface data outside the simulation domain to create wrfsfdda_d<domain> and then run "wrf.exe "; (3) do OBSGRID with "met_em*" files and observation surface data in partial region of simulation domain to create wrfsfdda_d<domain> and then run "wrf.exe". Experiments (2) and (3) share the same namelist.input file. I find the results of 3 experiments are different. Besides, the different regions of 2-m temperature and soil moisture between experiments (2) and (3) are basically in the region of soil assimilation by indirect soil nudging. The different regions of 2-m temperature and soil moisture between experiments (1) and (3) are not similar with different regions between experiments (2) and (3). So the data in files "met_em*" may be also assimilated. But why and how?
I will apreciate it if someone could explain it and provide some references.
Recently, I run an assimilation experiment of indirect soil nudging with Pleim-Xiu Land Surface Model in WRF3.9.1. The section fdda in namelist.input are shown below:
& fdda
grid_fdda = 1, 0, 0,
gfdda_inname = "wrffdda_d<domain>",
gfdda_interval_m = 360, 360, 360,
gfdda_end_h = 360, 240, 240,
io_form_gfdda = 2,
fgdt = 0, 0, 0,
if_no_pbl_nudging_uv = 0, 0, 0,
if_no_pbl_nudging_t = 1, 0, 0,
if_no_pbl_nudging_q = 1, 0, 0,
if_zfac_uv = 1, 0, 0,
k_zfac_uv = 10, 10, 10,
if_zfac_t = 0, 0, 0,
k_zfac_t = 10, 10, 10,
if_zfac_q = 0, 0, 0,
k_zfac_q = 10, 10, 10,
guv = 0.0000
gt = 0.0000
gq = 0.0000
if_ramping = 1,
dtramp_min = 60.0,
grid_sfdda = 1, 0, 0,
sgfdda_inname = "wrfsfdda_d<domain>"
sgfdda_interval_m = 180, 180,
sgfdda_end_h = 360, 2184,
io_form_sgfdda = 2,
guv_sfc = 0.0000, 0.0000,
gt_sfc = 0.0000, 0.0000,
gq_sfc = 0.0000, 0.0000,
rinblw = 250.,
pxlsm_soil_nudge = 1, 1, 1,
/
I set "guv, gt, gq,guv_sfc, gt_sfc and gq_sfc equal 0" because I just need the observation surface data in wrfsfdda_d<domain> file to do indirect soil nudging. The wrfsfdda_d<domain> file is created by Objective Analysis (OBSGRID) with "met_em*" files and Surface data files in NCEP BUFR format(http://rda.ucar.edu/datasets/ds461.0/). In the assimilation experiment, I just assimilate the soil moisture and twmperature of partial region of the Model simulation domain because I just want to investigate the impact of soil assimilation in partial region on the precipition in the whole Model simulation domain. Therefore, I wonder if the data in "met_em*" files influence the assimilation, or if the data in files "met_em*" are also assimilated by the file "wrfsfdda_d<domain>" file.
For my question, I have done some works. I compared 3 experiments: (1) no assimilation; (2) do OBSGRID with files "met_em*" and observation surface data outside the simulation domain to create wrfsfdda_d<domain> and then run "wrf.exe "; (3) do OBSGRID with "met_em*" files and observation surface data in partial region of simulation domain to create wrfsfdda_d<domain> and then run "wrf.exe". Experiments (2) and (3) share the same namelist.input file. I find the results of 3 experiments are different. Besides, the different regions of 2-m temperature and soil moisture between experiments (2) and (3) are basically in the region of soil assimilation by indirect soil nudging. The different regions of 2-m temperature and soil moisture between experiments (1) and (3) are not similar with different regions between experiments (2) and (3). So the data in files "met_em*" may be also assimilated. But why and how?
I will apreciate it if someone could explain it and provide some references.