----------Urgent HELP ____Not realistic concentrations of PM10, SO2 and O3

[Alice Burton]

Dear all,


I run the WRF-Chem version 4.5.2 with chem option 202. However, to check the simulation results, I noticed the concentrations of PM10, SO2, and O3 are not realistic.
The model significantly underestimates O3 and PM10 concentration and overestimates SO2 concentration (please check the attached screenshots).
I also attached my name list.

In terms of PM10, I need to mention once I use dust_opt = 1 (like now) the model underestimates PM10 concentration, while using dust_opt = 3 strongly overestimates PM10 concentration.

I wonder why this happens to me, please. May I ask you please to kindly advise me in this regard?

Best wishes,

[Mary Barth]

Hi Alice,

You need to use dust_opt = 13 when running with chem_opt=202. 

I think in an earlier email, we noted that reasons for the results are difficult to provide when we do not have the context of where the time series is located. 

Nevertheless, please review the wrfinput file to be sure these constituents look appropriate. Also review the wrfchemi files for the same reason.  O3 often goes to near zero when NOx is very high. So, it is good to check NO and NO2 concentrations.

Below I provide the &chem section of my chem_opt=202 namelist that ran with v4.0.3. I am running only 1 domain, so just look at the first column of namelist values. 

Regards,

Mary

^--^--^--^--^--^--^--^--^--^--^--^--^--^--^-^--^--^--^-^--^

Mary Barth 

Senior Scientist   

phone: 303-497-8186    email: bar...@ucar.edu

NSF - National Center for Atmospheric Research

P.O. Box 3000

Boulder, CO 80307

Staff web page

SIMA Web Site

MUSICA Web Site

DC3 Web Site 

^--^--^--^--^--^--^--^--^--^--^--^--^--^--^-^--^--^--^-^--^

&chem
 chem_opt                            = 202,    202,  112,
 chem_in_opt                         = 0,      1,    1,
 io_style_emissions                  = 1,
 chemdt                              = 1,     1,   0.5,
 bioemdt                             = 10,      2,    2,
 kemit                               = 10,
 photdt                              = 30,     30,   30,
 phot_opt                            = 4,      4,    4,
 emiss_opt                           = 10,     8,    8,
 gas_drydep_opt                      = 1,      1,    1,
 aer_drydep_opt                      = 1,      1,    1,
 bio_emiss_opt                       = 3,      3,    3,
 ne_area                             = 500,
 emiss_inpt_opt                      = 102,    111,  111,
 biomass_burn_opt                    = 2,      2,     2,
 plumerisefire_frq                   = 30,     60,    60,
 dust_opt                            = 13,
 seas_opt                            = 3,
 dmsemis_opt                         = 0,
 aer_op_opt                          = 1,
 opt_pars_out                        = 1,
 gas_bc_opt                          = 1,    1,   1,
 gas_ic_opt                          = 1,    1,   1,
 aer_bc_opt                          = 1,    1,   1,
 aer_ic_opt                          = 1,    1,   1,
 gaschem_onoff                       = 1,      1,     1,
 aerchem_onoff                       = 1,      1,     1,
 wetscav_onoff                       = 1,      1,     1,
 cldchem_onoff                       = 1,      0,     0,
 vertmix_onoff                       = 1,      1,     1,
 chem_conv_tr                        = 1,      0,     0,
 conv_tr_wetscav                     = 1,      0,     1,
 conv_tr_aqchem                      = 1,      0,     1,
 have_bcs_chem                       = .true., .true., .true.,
 have_bcs_tracer                     = .true., .true.
 have_bcs_upper                      = .false., .false., .false.,
 aer_ra_feedback                     = 1,       1,   1,
 chemdiag                            = 1,
 scale_fire_emiss                    = .true.,
 is_full_tuv                         = .true.,
 has_o3_exo_coldens                  = .true.,
 pht_cldfrc_opt                      = 2,
 cld_od_opt                          = 2,
 n2o5_hetchem                        = 0

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[Alice Burton]

Dear Mary,

Somany thanks for your advice. I considered 9 days as a spin-up, and the plots I sent were related to  day 10th and 11th  of the simulation. I also attached the NO and NO2 concentrations. What is your opinion  about them? Do you think low concentration of ozone is related to NOx concentration please? 

I also need your advice about SO2 concentration please.

Look forward to hearing from you.

Kind regards,

[Mary Barth]

Alice,

NO, NO2, and SO2 are very high if they are indeed in ppb units.

Mary

^--^--^--^--^--^--^--^--^--^--^--^--^--^--^-^--^--^--^-^--^

Mary Barth 

Senior Scientist   

phone: 303-497-8186    email: bar...@ucar.edu

NSF - National Center for Atmospheric Research

P.O. Box 3000

Boulder, CO 80307

Staff web page

SIMA Web Site

MUSICA Web Site

DC3 Web Site 

^--^--^--^--^--^--^--^--^--^--^--^--^--^--^-^--^--^--^-^--^

[Alice Burton]

Mary,

As you can see NO and NO2 concentrations in my study area are high and the model roughly indicates it. As you mentioned if NOx concentration is high then ozone concentration would decrease. So considering all these issues, how can I simulate ozen correctly?

Please kindly advise me.

Thank you. Regards

[Alice Burton]

Hi again,

I noticed that I did not use mozbc, and so I got those low emissions for ozone. However, I ran (using WACCM data) it and the results are now better, but I noticed the simulated ozone peak happened before the measured ozone peak. I am keen on knowing why this happens and how I can match both simulated and observed peaks. (please check the attached screenshots)

Regarding PM10 concentrations, as you mentioned before I used dust option 13, but simulated PM10 is still significantly low. Would you please kindly advise me on this issue.

 I attached my anthropogenic and mozbc script that I use to produce anthropogenic emission files and initial and boundary conditions respectively. Do you think there is any mistake in the script ( specially equation related to PM 10). 

Please kindly help me.

Kind regards,