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Open Source EMEP/MSC-W model
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EMEP output #85

Open janamol opened 3 years ago

janamol commented 3 years ago

Hi, I have a question about how to set up the model output. I have found some answers in issue #48 but would like to confirm: NH4 seems to be present only in the fine-mode particles NH4_F, no NH4_C is that correct? I need to output PM2.5 and PM10 not including the associated water. Studying the Simpson et al., 2012 paper, I was not sure if PMFINE, PMCO and PM10 are with or without water but from comment in #48 I have concluded that these should be without the associated water as there are listed the same parameters with _RH50 in the name which looks like the conditions for calculation of the PM-associated water described in Simpson et al., 2012. In the config_emep.nml which comes with rv4.34, in OutputConcs PMFINE is output both in 'ug' and in 'ug_PM'. What is the difference? Looks like it is OM25, OMCOARSE, ASOA and BSOA also using both the ug_PM and ug outputs, somewhere I have read that in that case ug includes semivolatiles in the gas phase while ug_PM only include the particulate-phase organics. Would it be the same case for PMFINE?

svetlanat commented 3 years ago

Hi, I hope those answers will be useful:

  1. Correct. NH4 is only present in the fine fraction (NH4_F)
  2. PMFINE, PMCO and PM10 are dry mass (without water), and so is SURF_ug_PM25 (which is = PMFINE+0.27*NO3_C)
  3. PMFINE in 'ug' is fine to use. You are right about 'ug' (gas+particles) and 'ug_PM' (only particles) for semi-volatile organics, but I'm not sure if this is the case for PMFINE'. @mifads Dave, could you clarify PMFINE in 'ug_PM'
janamol commented 3 years ago

Hi Svetlana, Many thanks for your answers, good to know. May I ask what is the reason behind SURF_ug_PM25? Best regards Jana

mifads commented 3 years ago

Hi Svetlana, Jana,

   @mifads Dave, could you clarify PMFINE in 'ug_PM'

PMFINE uses "OM25_p" (see CM_ChemGroups_mod), which is the particulate sum of OM species. So, no gas-phase.

janamol commented 3 years ago

Hi Dave, Thanks! Just to doublecheck, does it mean that PMFINE in ‘ug’ and in ‘ug_PM’ is the same?

mifads commented 3 years ago

Hi Jana,

Yes, PMFINE is special that way. Confusing I know!

svetlanat commented 3 years ago

Hi Jana,

Regarding SURF_ug_PM25, we assume that a fraction of coarse NO3 (if you imagine a log-normal distribution) will be in particles smaller than 2.5 mkm.

Svetlana

janamol commented 3 years ago

Thanks Svetlana, I have found Table 6 in Simpson et al., 2012 now, that explains it. Best regards /Jana

janamol commented 3 years ago

One more question regarding the organic part, if I may. Do I understand this correctly?: 'OM25' 'ugC_PM' is OC, only the particulate phase 'OM25' 'ugC' is OC, particulate + semi-volatile phase (if this unit exists) 'OM25' 'ug_PM' is OM (=~OC*1.3) only the particulate phase 'OM25' 'ug_PM' is OM, particulate + semi-volatile phase