the pm25 in arid region is low with cesm2.2 mosaic

[xiaoxiaokuishu]

Hi, all

I use cesm2.2-mosaic to simulate pm25 with below settings.

&dust_nl
dust_emis_fact = 0.7D0
soil_erod_file = 'dst_source2x2tunedcam6-2x2-04062017.nc'
/

but my dust concentrations are very low in the desert regions (comparing PM25 and dust concentrations to CAMS reanalysis, see below figure).
Not sure if there is an issue for dust in cesm2.2 with mosaic.

 

[Danny Leung]

Hi Ru-
My understanding is that the dust model is doing what it wants to do, it's just that the dust model in CESM2 is not very well tuned. The Zender_2003 scheme, as you pointed out, uses the source function (soil_erod_file) that masks out dust emissions from a large part of the Sahara. Those parts where you see from your plot with low dust likely emit little or zero dust (see Fig. 2 of this paper).
That's why the CESM team is replacing the Zender_2003 scheme with a newer dust emission model from that paper in the later CESM versions.
I don't know if you need dust PM2.5 from your run to be right if your main interest is MOSAIC. Hmm, but, since the metal ions are taking part in the MOSAIC system for gas-particle partitioning, particulate nitrate and ammonium will likely reduce in the accumulation mode and move to the coarse mode when there is more dust.
Does this help?
Danny

 

[xiaoxiaokuishu]

Hi Ru-
My understanding is that the dust model is doing what it wants to do, it's just that the dust model in CESM2 is not very well tuned. The Zender_2003 scheme, as you pointed out, uses the source function (soil_erod_file) that masks out dust emissions from a large part of the Sahara. Those parts where you see from your plot with low dust likely emit little or zero dust (see Fig. 2 of this paper).
That's why the CESM team is replacing the Zender_2003 scheme with a newer dust emission model from that paper in the later CESM versions.
I don't know if you need dust PM2.5 from your run to be right if your main interest is MOSAIC. Hmm, but, since the metal ions are taking part in the MOSAIC system for gas-particle partitioning, particulate nitrate and ammonium will likely reduce in the accumulation mode and move to the coarse mode when there is more dust.
Does this help?
Danny

Thanks Danny!!