Difference between revisions of "The gases.def Input File"
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| + | Note: the gases.def file is used by the Generic PCM. | ||
A typical ''gases.def'' file for the Earth case: | A typical ''gases.def'' file for the Earth case: | ||
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* The second line must contain the number of gases (here 3) accounted for | * The second line must contain the number of gases (here 3) accounted for | ||
* Then come the gas names (always 3 characters!), one per line. Here '''N2_''', '''CO2''' and '''H2O''' | * Then come the gas names (always 3 characters!), one per line. Here '''N2_''', '''CO2''' and '''H2O''' | ||
| − | * Followed by the gas mixing ratios, if the gas concentration is assumed to be constant, or '''-1''' if it is variable. In the example given above ''N2'' and ''CO2'' will be taken as having constant mixing ratios of respectively ''0.9996119'' and ''0.375999962E-03'', whereas ''H2O'' will be variable. | + | * Followed by the gas volume mixing ratios (mol/mol_of_atm), if the gas concentration is assumed to be constant, or '''-1''' if it is variable. In the example given above ''N2'' and ''CO2'' will be taken as having "constant" mixing ratios of respectively ''0.9996119'' and ''0.375999962E-03'', whereas ''H2O'' will be variable. By "constant" is mean the proportion wrt to 1.0 (the normalized amount of the sum of all tracers) i.e. in the example above, since 0.9996119+0.375999962E-03=0.999987899962 these exact values are for when the volume mixing ratio of H2O is 1.21e-5 mol/mol. |
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== Technical aspects == | == Technical aspects == | ||
In the code this file is read by the ''su_gases'' routine, which handles only preset possibilities (gas names). | In the code this file is read by the ''su_gases'' routine, which handles only preset possibilities (gas names). | ||
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| + | [[Category:Inputs]] | ||
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| + | [[Category:Generic-Model]] | ||
Latest revision as of 10:42, 30 April 2025
Note: the gases.def file is used by the Generic PCM.
A typical gases.def file for the Earth case:
# gases 3 N2_ CO2 H2O 0.999611900E+00 0.375999962E-03 -1 # First line is number of gases # Followed by gas names (always 3 characters) # and then mixing ratios. # mixing ratio -1 means the gas is variable.
- Note that the first line of the file is actually not read
- The second line must contain the number of gases (here 3) accounted for
- Then come the gas names (always 3 characters!), one per line. Here N2_, CO2 and H2O
- Followed by the gas volume mixing ratios (mol/mol_of_atm), if the gas concentration is assumed to be constant, or -1 if it is variable. In the example given above N2 and CO2 will be taken as having "constant" mixing ratios of respectively 0.9996119 and 0.375999962E-03, whereas H2O will be variable. By "constant" is mean the proportion wrt to 1.0 (the normalized amount of the sum of all tracers) i.e. in the example above, since 0.9996119+0.375999962E-03=0.999987899962 these exact values are for when the volume mixing ratio of H2O is 1.21e-5 mol/mol.
Another example of a gases.def file, from the Early Mars case, where only two gases are considered, CO2 and H2O, with only H2O as variable:
# gases 2 CO2 H2O 1.0 -1 # First line is number of gases # Followed by gas names (always 3 characters) # and then mixing ratios. # mixing ratio -1 means the gas is variable.
Technical aspects
In the code this file is read by the su_gases routine, which handles only preset possibilities (gas names).
