Changes between Version 2 and Version 3 of doc/app/chememi

Timestamp:

Nov 20, 2019 2:49:22 PM (5 years ago)

Author:

banzhafs

Comment:

--

doc/app/chememi

@@ -7 +7 @@
 This page is under construction.
 
-In PALM-4U emissions can be applied in three different ways:
+Emissions of gases and/or passive compounds can be provided by the user in different levels of detail (LOD). Three modes were implemented.
+Two modes require emission data from file. Gridded emission information can be provided in two LODs via a netCDF file (see also [https://palm.muk.uni-hannover.de/trac/wiki/doc/app/iofiles/pids] PALM Input Data Standard):
 
- • PARAMETERIZED: Traffic emissions are parameterized depending on the the values of street_type in the static file. Emission values for each street type and chemical compound must be supplied in the namelist as described below. No other emissions are considered. street_type can be obtained from OpenStreetMap.
+ • LOD 1 files require annual emission information which are temporally disaggregated by PALM-4U using sector-specific standard time factors
 
- • DEFAULT: Gridded yearly emissions must be supplied by the user as specified in the PIDS document (see sample emissions file). Typical temporal variations are apllied by PALM4U.
+ • LOD 2 files must contain pre-processed emission information that is already temporally disaggregated. At the moment hourly emission data is required. Other temporal intervals will be possible in later versions. IMPORTANT: In this mode the initial date of the simulation has to coincide with the first day for which emission values are available.
 
- • PRE-PROCESSED: Preprocessed hourly (other temporal intervals will be possible in later versions) 3-d emission fields must be supplied by the user. 
+In a third mode traffic emissions are parameterized on the basis of the street type classification provided by OpenStreetMap and street type specific emissions factors. This option, named ’Parameterized’ mode, is currently only implemented for the traffic sector:
 
-Importantly, for the DEFAULT and the PRE-PROCESSED mode of the emissions, the exact date of the start of the simulation must be indicated through the namelist parameter date_init of the date_and_time_mod module. 
-
-IMPORTANT: In the PRE-PROCESSED mode the initial date of the simulation has to coincide with the first day for which emission values are available. 
-
-Find a more detailed description of the PALM-4U emission input in the corresponding attached document [https://palm.muk.uni-hannover.de/trac/attachment/wiki/doc/app/chempar/chem_emissions_PALM4U.pdf here]. 
+ • LOD 0 requires a mean surface emission per day (in micromol/m2/d for gases and in kg/m2/d for particulate matter) for each desired species contained in the applied chemical mechanism together with a weight differing between main and side road emissions defined in the PALM Fortran namelist file (see also [https://palm.muk.uni-hannover.de/trac/wiki/doc/app/par] model setup, [https://palm.muk.uni-hannover.de/trac/wiki/doc/app/chemistry_parameters] chemistry parameters). Furthermore, the street type classification provided by OpenStreetMap must be included in the PALM static driver (see [https://palm.muk.uni-hannover.de/trac/wiki/doc/app/iofiles/pids/static] Static input file)
+ 
+To account for the temporal distribution of the parameterized traffic emissions a diurnal profile based on urban traffic counts is implemented to disaggregate the total emission of the different species to hourly values. Currently, the applied temporal profile is the same for all species and main and side roads.