PMIP 2 Land-Surface and Vegetation Variables

Note: the list of required variables is not stable yet. You will find in the tables below the variables that are likely to be found in the database, and the variables that were suggested as useful but did not make it to the final list.

Required variables

Coordinator(s)	Updated
Nathalie de Noblet / LSCE	03/10/2005

Name(s)	Units	Description	Axes	Frequency				DB
Name(s)	Units	Description	Axes	DA	MO	SE	AN	DB
Required variables
[vcarcont] [vegetation... ..._carbon_content]	kg m-2	Total vegetation carbon (above ground & roots)	XYT			O	O	G
[vcarcontpft] [vegetation... ..._carbon_content]	kg m-2	Total vegetation carbon (above ground & roots) by PFT	XYVT			V_n	V_n	G
[scarcont] [soil... ..._carbon_content]	kg m-2	Soil carbon content	XYT			O	O	G
[pftfrac] [pft_fraction]	1	PFT fractions	XYVT			V_n	V_n
[npp] [net_primary... ..._productivity... .._of_carbon]	kg m-2 s-1	NPP of vegetation	XYT		O	O		G
[npppft] [net_primary... ..._productivity... .._of_carbon]	kg m-2 s-1	NPP of vegetation by PFT	XYVT		V_n	V_n		G
[laipft] [leaf_area_index]	1	Leaf Area Index by PFT	XYVT		V_n	V_n
[bioburnt] [biomass_burnt]	kg m-2 s-1	Total biomass burnt	XYT		O	O
[lcarcont] [litter_carbon]	kg m-2	Litter carbon	XYT			O	O
[lcarcontpft] [litter_carbon]	kg m-2	Litter carbon by PFT	XYVT			V_n	V_n
[hresp] [heterotrophic... ..._respiration... ..._carbon_flux]	kg m-2 s-1	Heterotrophic respiration (I.e. respiration from the soil but not including root respiration)	XYT		O	O	O	G
[cheight] [canopy_height]	m	Canopy height	XYT			O	O
[cheightpft] [canopy_height]	m	Canopy height by PFT	XYT			O	O
[gpp] [gross_primary... ..._productivity... ..._of_carbon]	kg m-2 s-1	Total gross primary production (GPP)	XYT		O	O		G
[gpppft] [gross_primary... ..._productivity... ..._of_carbon]	kg m-2 s-1	Gross primary production (GPP) by PFT	XYVT		V_n	V_n		G
mrso soil... ..._moisture_content	kg m-2	Soil moisture (integrated over soil column)	XYT		O	O		A1a5
mrros surface... ..._runoff_flux	kg m-2 s-1	Surface runoff rate	XYT			O		A1a21
mrro runoff_flux	kg m-2 s-1	Total runoff rate (including drainage)	XYT			O		A1a22
[dis] [river... ..._discharge]	m3 s-1	Simulated River Discharge	XYT			O		G
[tsoil] [soil... ..._temperature]	K	Average layer soil temperature	XYST			S_n		G
evspsblveg water... ..._evaporation... ..._flux... ..._from_canopy	kg m-2 s-1	Total canopy evaporation	XYT			O		A1f2
[trans] [transpiration... ..._flux]	kg m-2 s-1	Total plant transpiration	XYT			O		G
[transpft] [transpiration... ..._flux]	kg m-2 s-1	Plant transpiration by PFT	XYVT			V_n		G
[esoil] [water... ..._evaporation... ..._flux... ..._from_soil]	kg m-2 s-1	Bare soil evaporation	XYT			O		G
[potevap] [potential... ..._evaporation]	kg m-2 s-1	Potential evaporation	XYT		O			G
[potevappft] [potential... ..._evaporation]	kg m-2 s-1	Potential evaporation by PFT	XYVT			V_n		G
Number of variables: 26
Estimated database size
MO: 6 MO-3D-20: 3			2475.0 Mb / 100 year(s)
SE: 16 SE-3D-20: 8 SE-3D-5: 1			67.9 Mb
AN: 6 AN-3D-20: 3			206.2 Mb / 100 year(s)
DB STORAGE REQUIRED = 2.7 Gb

High frequency surface processes variables required by the Dust Model

Please check Sandy Harrison's note to get full details about the dust model variables! The following table lists the variables that either are not required at all at DAily frequency in the PMIP 2 database, or are not required at a high enough frequency (sub-DAily) for the dust model.

Rejected variables

Name(s)	Units	Description	Axes	Frequency
DA	MO	SE	AN
mrso	kg m-2	Soil moisture (in the top meter? at root depth?)	XYT	O	A
Number of variables: 1
Estimated database size
DA: 1	562.5 Mb / 50 year(s)
DB STORAGE REQUIRED = 0.5 Gb

Name(s)	Units	Description	Axes	Frequency				DB
Name(s)	Units	Description	Axes	DA	MO	SE	AN	DB
Variables moved to the Atmosphere Variables' list
orog	m	Orography	XY					A
ts	K	Ground surface temperature (surface skin temperature?)	XYT					A
tas	K	2m air temperature	XYT					A
pr	kg m-2 s-1	Total precipitation	XYT					A
huss	kg kg-1	Surface specific humidity (2m)	XYT					A
hurs	100	Surface relative humidity (2m)	XYT					P
clt	100	Total cloud cover	XYT					P
snc	100	Snow cover	XYT					A
snd	m	Snow depth	XYT					A
ps	Pa	Surface pressure	XYT					A
uas	m s-1	Surface (10m) eastward wind	XYT					A
vas	m s-1	Surface (10m) northward wind	XYT					A
hfss	W m-2	Heat flux sensible surface	XYT					A
albs	100	Surface albedo	XYT					A2
rss	W m-2	SW radiation net surface	XYT					A
rlus	W m-2	LW radiation upward surface	XYT					A
rls	W m-2	LW radiation net surface	XYT					A
Number of variables: 17
Other rejected variables
SAlbedo	-	Snow albedo	XYT					G
Ecanop	kg m-2 s-1	Interception evaporation	XYZ					G
EvapSnow	kg m-2 s-1	Snow Evaporation	XYZ					G
SubSurf	kg m-2 s-1	Sublimation of the snow free area	XYT					G
Ewater	kg m-2 s-1	Open water evaporation	XYT					G
Qg	W m-2	Ground heat flux (note: hf into the ground)	XYT					G
mrfso soil_frozen... ..._water_content	kg m-2	Total soil frozen water content	XYT					A1a20
Qrec	kg m-2 s-1	Recharge (note: recharge from river to the flood plain)	XYT					G
SoilMoist	kg m-2	Average layer soil moisture	XYVT					G
SMLiqFrac		Average layer fraction of liquid moisture	XYVT					G
SoilWet	kg m-2	Total soil wetness	XYVT					G
CanopInt	kg m-2	Total canopy water storage	XYVT					G
DelSurfStor	kg m-2	Change in surface water storage	XYT					G
SurfStor	kg m-2	Surface water storage	XYT					G
WaterTableD	m	Water table depth	XYT					G
prsn	kg m-2 s-1	Snowfall rate (water equivalent)	XYT					A
Qa	W m-2	Advective energy	XYT					G
Qf	W m-2	Energy of fusion	XYT					G
Qtau	N m-2	Momentum flux	XYT					G
Qv	W m-2	Energy of sublimation	XYT					G
sic	%	Sea-ice concentration	XYT					A
RainfSnowFrac		Fraction of rainfall on snow	XYT					G
SnowfSnowFrac		Fraction of snowfall on snow	XYT					G
SliqFrac		Snow liquid fraction	XYT					G
snm	kg m-2 s-1	Snow melt	XYT					A1
snw	kg m-2	Snow depth (water equivalent)	XYT					A
SWEVeg	kg m-2	SWE intercepted by the vegetation	XYT					G
Qfz	kg m-2 s-1	Re-freezing of water in the snow	XYT					G
Qst	kg m-2 s-1	Snow throughfall (note: Liquid water flowing out of the snow pack)	XYT					G
SnowT	K	Snow surface temperature	XYT					G
SnowTProf	K	Temperature profile in the snow	XYZ					G
BaresoilT	K	Temperature of bare soil	XYT					G
RadT	K	Surface Radiative Temperature	XYT					G
VegT	K	Vegetation canopy temperature	XYVT					G
NEE	kg m-2 s-2	Net ecosystem exchange	XYVT					G
Autoresp	kg m-2 s-2	Autotrophic respiration	XYVT					G
	???	Leaf turnover rate	XYVT
Resp	kg m-2 s-2	Total respiration on PFTs	XYVT
	kg m-2 s-2	Soil respiration	XYT
	?	Land snow melt heat flux	XYT
	?	Total moisture delivered to the boundary layer	XYT
RootMoist	kg m-2	Soil water content in root zone	XYVT					G
fdepth	m	Frozen soil depth	XYT					G
tdepth	m	Depth to soil thaw	XYT					G
SMFrozFrac	?	Soil frozen fraction in first layer (or in root zone)	XYVT					G
rlength	m	Roughness length	XYT
gs	m s-1	Canopy conductance	XYVT
SubSnow	kg m-2 s-1	Snow sublimation	XYT					G
evap	kg m-2 s-1	Total evapotranspiration (includes transpiration)	XYT					G
ACond	m s-1	Aerodynamic conductance	XYT
Qsb	kg m-2 s-1	Subsurface runoff	XYT					G
	?	Canopy throughfall	XYT
	kg m-2	Total soil water content (vertically integrated)	XYT
Number of variables: 53

Notes

Michel Crucifix

One difficulty arising from the various variable lists is that much information is redundant. Part of the problem could be solved by creating a separate list, called 'land surface processes', which, basically, would consider the diagnostics and prognostics of the land surface scheme.

Another difficulty is the very large number of variables. The number of variables to be centrally held and managed should not exceed 20 per module and per model, 5 to 10 of which only being compulsary. A more restrictive list presents both advantages of reducing our data storage requirements and improve the intrinsic quality of each variable (better control, quality check, better definition etc.) If a particular model seems to show a response specifically different from the others, it is always time to look at some very specific varibles, with the support of the expert on that model.

Can we make clear what we mean by soil wetness, soil moisture, and soil water content?


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