Code Table 4.2 - New parameters and table for vegetation/irrigation/wetland (code Table 4.2 and new Code table 4.239 )

[sebvi]

Summary and purpose

ECMWF is requesting new parameters within Code Table 4.2 and a new Code Table 4.239 to support its Land surface modelling activities

Action proposed

The team is kindly asked to review and approve the contents for inclusion within the next update to the WMO Manual on Codes.

Discussions

ECMWF is requesting 5 new parameters to support Land surface modelling. One of the parameter, Wetland type, requires an auxilliary table working using the same mechanism than the existing "type" parameters: precipitation type, cloud type, etc.

Detailed proposal

add in Code Table 4.2, Discipline " 2 - Land surface products"	Code	Meaning	Units	Description
45	Wetland Cover	proportion	This parameter is the fraction of the grid box (0-1) which is inundated.This includes marshes, fens, bogs and swamps but excludes lakes, reservoirs, riversand coral reefs.
46	Wetland Type	Code table 4.239	This parameter indicates the 12types of wetlands recognised by the ECMWF IFS wetland emissions model. They are used to calculate the wetland methane fluxes.
47	Irrigation Cover	proportion	This parameter is the fraction of the grid box (0-1) that is subject to irrigation.
48	C4 crop cover (see Note)	proportion	This parameter is the fraction of the grid box (0-1) with C4 crops.
49	C4 grass cover (see Note)	proportion	This parameter is the fraction of the grid box (0-1) withC4 grass.

Note:

create a new Code Table 4.239 "Wetland Type"	Code	Meaning
0	reserved
1	Bog
2	Drained
3	Fen
4	Floodplain
5	Mangrove
6	Marsh
7	Rice
8	Riverine
9	Salt marsh
10	Swamp
11	Upland
12	Wet Tundra
13 -191	Reserved
192 -254	Reserved for local use
255	Missing

[amilan17]

re https://github.com/wmo-im/CCT/wiki/Teleconference-26-and-28.4.2022

In discussion, Sebastien to follow up with Sibylle over whether new descriptor / table is required for wetland type or whether it can be merged with an existing land cover table.

[amilan17]

https://github.com/wmo-im/CCT/wiki/Teleconference-18-and-19.5.2022 notes:

Sibylle said it's ok to create a new table.

@sebvi add note about C4 in this file: https://github.com/wmo-im/GRIB2/blob/issue147/notes/CodeFlag_notes.csv

[sebvi]

branch updated

[amilan17]

https://github.com/wmo-im/CCT/wiki/Teleconference-8.6.2022 notes:

branch is ready, @sebvi update issue summary with note; @marijanacrepulja validate;

[marijanacrepulja]

@sebvi, @SibylleK, @amilan17

I am reading description of Wetland Type. The first sentence is specific to ECMWF saying "This parameter indicates the 12types of wetlands recognised by the ECMWF IFS wetland emissions model." Do we want to make description more generic, so other NWP centres can use it is as well. Is it sufficient if we have only second sentence in description?

[sebvi]

The descriptions are not part of the tables, it will not be visible in the branch, only in the github issue so I think it is fine.

[marijanacrepulja]

@amilan17 the branch is ready, please review and move to "Ready to FT"