4.7.3. Namelist NAM_CH_SNAP_EMIS_PGD

• NEMIS_NBR : number of chemical pgd fields chosen by user
• NEMIS_SNAP : number of snaps
• CEMIS_NAME : name of the chemical fields (emitted species)
• CEMIS_COMMENT : comment on the chemical fields (emitted species)
• CSNAP_MONTHLY_FILE : name of the snap ASCII monthly file
• CSNAP_DAILY_FILE : name of the snap ASCII daily file
• CSNAP_HOURLY_FILE : name of the snap ASCII hourly file
• CSNAP_POTENTIAL_FILE : name of the snap potential file
• CSNAP_POTENTIAL_FILETYPE : type of the snap potential file
• XUNIF_SNAP : uniform value for the snap potential (emission factore for each chemical specie and each snap)
• XUNIF_DELTA_LEGAL_TIME : uniform value for the difference (in hours) between lagal time and UTC time
• CDELTA_LEGAL_TIME_FILE : name of file for the difference between legal time and UTC time
• CDELTA_LEGAL_TIME_FILETYPE : filetype for the difference between legal time and UTC time

In order to compute the emissions using the SNAP (Selected Nomenclature for Air Pollution) approach, the user needs to provide :

for each SNAP category AND for each chemical component emitted (in the emission inventory, not emitted to the atmosphere), the map of the emission potential

3 files describing the temporal evolution of each emitted chemical component for each snap. Note that all chemical species emitted by one snap will follow the same temporal evolution. But for the same chemical emission between two different snaps (e.g. industry, traffic), the temporal evolution can be different. The 3 files describe :

• the annual cycle (with a monthly timescale)
• the weekly cycle (with a daily time scale), typically to separate weekdays, saturdays and sundays.
• The diurnal cycle (with an hourly time scale). Note here that the hypothesis is done that the diurnal evolution is the same whatever the day in the week. The reference for the calculation of the hour (UTC, solar, legal) is provided at the beginning of this file. This allows to have different timing in different places at the same UTC (if solar or legal time is chosen), for example between China and Europe.

Here are examples of these files (please note that these must be provided for each chemical component separately) :

Annual cycle (one SNAP per line, one Month per column, from January to December)

Monthly evolution of the coefficients for the 10 snaps
1.2 1.15 1.05 1 0.9 0.85 0.8 0.875 0.95 1 1.075 1.15
1.7 1.5 1.3 1 0.7 0.4 0.2 0.4 0.7 1.05 1.4 1.65
1.1 1.075 1.05 1 0.95 0.9 0.93 0.95 0.97 1 1.025 1.05
1.02 1.02 1.02 1.02 1.02 1.02 1 0.84 1.02 1.02 1.02 0.9
1.2 1.2 1.2 0.8 0.8 0.8 0.8 0.8 0.8 1.2 1.2 1.2
0.95 0.96 1.02 1 1.01 1.03 1.03 1.01 1.04 1.03 1.01 0.91
0.88 0.92 0.98 1.03 1.05 1.06 1.01 1.02 1.06 1.05 1.01 0.93
0.88 0.92 0.98 1.03 1.05 1.06 1.01 1.02 1.06 1.05 1.01 0.93
1 1 1 1 1 1 1 1 1 1 1 1
0.45 1.3 2.35 1.7 0.85 0.85 0.85 1 1.1 0.65 0.45 0.45

Weekly cycle (one SNAP per line, one day per column, from Monday to Sunday)

1.06 1.06 1.06 1.06 1.06 0.85 0.85
1.08 1.08 1.08 1.08 1.08 0.8 0.8
1.08 1.08 1.08 1.08 1.08 0.8 0.8
1.02 1.02 1.02 1.02 1.02 1.02 1
1 1 1 1 1 1 1
1.2 1.2 1.2 1.2 1.2 0.5 0.5
1.02 1.06 1.08 1.1 1.14 0.81 0.79
1 1 1 1 1 1 1
1 1 1 1 1 1 1
1 1 1 1 1 1 1

Diurnal cycle ( one SNAP per line, one Hour per column, from 00h to 23h, definition for time calculation in first line)

’SOLAR’
Hourly Evolution for the 10 snaps
0.72 0.71 0.74 0.8 0.92 1.08 1.19 1.22 1.21 1.21 1.17 1.15 1.14 1.13 1.1 1.07 1.04 1.02 1.02 1.01 0.96 0.88 0.79 0.72
0.36 0.36 0.37 0.5 1.19 1.53 1.57 1.56 1.35 1.16 1.07 1.06 1 0.98 0.99 1.12 1.41 1.52 1.39 1.35 1 0.42 0.38 0.36
0.78 0.82 0.88 0.95 1.02 1.09 1.16 1.22 1.28 1.3 1.22 1.24 1.25 1.16 1.08 1.01 0.95 0.9 0.85 0.81 0.78 0.75 0.75 0.75
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
0.2 0.1 0.1 0.2 0.75 1.25 1.4 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.4 1.25 1.1 1 0.9 0.8 0.7 0.5 0.35
0.06 0.05 0.09 0.22 0.86 1.84 1.86 1.41 1.24 1.2 1.32 1.44 1.45 1.59 2.03 2.08 1.51 1.06 0.74 0.62 0.61 0.44 0.19 0.09
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
0.6 0.6 0.6 0.65 0.75 0.9 1.1 1.35 1.45 1.6 1.8 1.75 1.7 1.55 1.35 1.1 0.9 0.75 0.65 0.6 0.6 0.6 0.6 0.6