EMISSION

Syntax:

EMISSION [ [LAND eeeee | SEA eeeee | SNOW eeeee] |

FILE xxxxxxxxx |

POINT eeeeee [nnN|nnS] [nnW|nnE] [nnnHPA] |

OH xxx eeeee eeeee eeeee |

DISTRIBUTION xxxxxxx nnn

nnnn eeee

nnnn eeee

....]

Where eeee are floating point number, xxxx are alphanumeric characters and nnn are integer numbers. There are five ways to define tracer emissions:

1. By defining land/sea/snow emissions in molecules.cm^-2.s^-1
2. By reading in a file that contains surface emissions (36x18) in (mixing ratio).s^-1
3. By defining point source fluxes in molecules.cm^-2.s^-1
4. By defining a source that results from a reaction: A + OH ---> Tracer
5. By defining an emission distribution and a number of yearly total amounts in kt.yr^-1

The first two and the last one are surface emissions, whereas 3 and 4 are volume emissions. Multiple POINT sources may be defined (maximum 100), in addition to one source of the kind FILE, OH, and LAND/SEA/SNOW and DISTRIBUTION. Point emissions are shifted towards the nearest grid-box.

Examples:

Rn is emitted over land at 1.0 molecule cm^-2 s^-1:

EMISSION LAND 1.0 SEA 0.0 SNOW 0.0

Define three point sources of 10⁵ molecules cm^-2 s^-1 molecules along 180E at 800 hPa:

EMISSION POINT 1e5 180E 45N 800HPA

EMISSION POINT 1e5 180E 5N 800HPA

EMISSION POINT 1e5 180E 45S 800HPA

Define CO emission due to methane oxidation CH₄ + OH --> CO. The global uniform concentration of CH₄ (or any other named species) is given first (in ppbv). Next, the reaction constant k is defined as

k = 2.95x10^-12 exp(-1820.0/T) (in cm³s^-1)

EMISSION OH CH4 1700.0 2.95e-12 -1820.0

Read (monthly varying) emissions from file co_emissions.dat

EMISSION FILE co_emissions.dat

Define emission distribution of methyl-chloroform and the emitted amounts (in kilotonnes per year) for 1975 and 1976:

EMISSION DISTRIBUTION mcf_dist.dat 2 (file name and the number of yearly emitted amounts)

1975 309.0

1976 382.0

Default: no emissions