PMIP 2 Atmosphere Variables


 

Coordinator(s) Updated
Paul Valdes / BRIDGE 03/14/2005

 

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

Name(s) Units Description Axes Frequency DB
DA MO SE AN
orog
surface_altitude
m Orography XY   1     A1b1
sftlf
land_area_fraction
% Surface type % land XY   1     A1b2
sftgif
land_ice_area_fraction
% Surface type % glacier XY   1     A1b3
ta
air_temperature
K Air temperature XYPT Pbm P3 P17   A1c2
A2b1
tas
air_temperature
K 2m air temperature XYT O O O   A1a3
A2a5
A3_3
tasmin
air_temperature
K Daily minimum surface (2m) temperature XYT O O O   A1f5
A2a3
tasmax
air_temperature
K Daily maximum surface (2m) temperature XYT O O O   A1f6
A2a4
ts
surface_temperature
K Surface skin temperature XYT   O O   A1a15
pr
precipitation_flux
kg m-2 s-1 Total precipitation XYT O O O   A1a2
A2a2
A3_2
prc
convective...
..._precipitation_flux
kg m-2 s-1 Convective precipitation XYT   O O   A1a18
[evspsbl]
[water_evaporation_flux]
kg m-2 s-1 Total surface evaporation XYT   O O   P
[sbls]
[water_sublimation_flux]
kg m-2 s-1 Sublimation (per unit area) XYT   O O   A1
prw
atmosphere...
..._water_vapor_content
kg m-2 Precipitable water XYT     O   A1a19
cl
cloud_area_fraction...
..._in_atmosphere_layer
% Cloud cover XYPT     P17   A1c1
clivi
atmosphere...
..._cloud_ice_content
kg m-2 Cloud ice XYT     O   A1a44
clt
cloud_area_fraction
% Total cloud cover XYT   O O   A1a42
clwvi
atmosphere...
..._cloud_condensed...
..._water_content
kg m-2 Cloud liquid water XYT     O   A1a43
snc
surface_snow...
..._area_fraction...
..._where_land
% Snow cover XYT   O O   A1a24
snd
surface...
..._snow_thickness
m Snow depth XYT   O O   A1a8
snm
surface...
..._snow_melt_flux...
..._where_land
kg m-2 s-1 Snow melt XYT   O O   A1a25
ps
surface_air_pressure
Pa Surface pressure XYT   O O   A1a16
psl
air_pressure...
..._at_sea_level
Pa Air pressure at sea level XYT   O O   A1a1
A2a1
A3_1
zg
geopotential_height
m Geopotential height XYPT Pm P3 P17   A1c7
[intuaw]
[vertical_integral...
..._eastward_wind...
..._by_total_water]
kg m-1 s-1 Vertically integrated Eastward moisture transport
Mass_weighted_vertical integral of the product of eastward wind by total water mass per unit mass
XYT   O O    
[intvaw]
[vertical_integral...
..._norhward_wind...
..._by_total_water]
kg m-1 s-1 Vertically integrated Northward moisture transport
Mass_weighted_vertical integral of the product of northward wind by total water mass per unit mass
XYT   O O    
[intuadse]
[vertical_integral...
..._eastward_wind...
..._by_dry...
..._static_energy]
1.e6 m-1 s-1 J Vertically integrated Eastward dry transport (cp.T +zg).u
Mass_weighted_vertical integral of the product of northward wind by dry static_energy per mass unit
XYT   O O    
[intvadse]
[vertical_integral...
..._northward_wind...
..._by_dry...
..._static_energy]
1.e6 m-1 s-1 J Vertically integrated Northward dry transport (cp.T +zg).v
Mass_weighted_vertical integral of the product of northward wind by dry static_energy per mass unit
XYT   O O    
hus
specific_humidity
kg kg-1 Specific humidity XYPT Pb P3 P17   A1c5
A2b4
hur
relative_humidity
% Relative humidity XYPT     P17   A1c8
huss
specific_humidity
kg kg-1 Surface specific humidity (2m) XYT   O O   A1a28
[hurs]
relative_humidity
% Surface relative humidity (2m) XYT     O   P
ua
eastward_wind
m s-1 Eastward wind XYPT Pbt P3 P17   A1c3
A2b2
va
northward_wind
m s-1 Northward wind XYPT Pbt P3 P17   A1c4
A2b3
wap
lagrangian_tendency...
..._of_air_pressure
Pa s-1 Pressure vertical velocity (omega) XYPT Pm P3 P17   A1c6
uas
eastward_wind
m s-1 Surface (10m) eastward wind XYT     O   A1a26
A2a12
vas
northward_wind
m s-1 Surface (10m) northward wind XYT     O   A1c4
A2b3
hfls
surface_upward...
..._latent_heat_flux
W m-2 Heat flux latent surface XYT   O O   A1a9
A2a6
A3_4
hfss
surface_upward...
..._sensible_heat_flux
W m-2 Heat flux sensible surface XYT   O O   A1a10
A2a7
A3_5
[hfns ?]
[surface_downward...
..._heat_flux_in_air]
W m-2 Heat flux net surface XYT     O   A
[albs]
surface_albedo
1 Surface albedo XYT   O O   A2
rsds
surface_downwelling...
..._shortwave_flux...
..._in_air
W m-2 SW radiation incident at the surface XYT     O   A1a13
A2a10
A3_8
rsdscs
surface_downwelling...
..._shortwave_flux...
..._in_air...
..._assuming_clear_sky
W m-2 SW radiation incident at the surface clear sky XYT     O   A1a37
rsus
surface_upwelling...
..._shortwave_flux...
.._in_air
W m-2 SW radiation upward (reflected) surface XYT     O   A1a14
A2a11
A3_9
rsuscs
surface_upwelling...
.._shortwave_flux...
.._in_air...
.._assuming_clear_sky
W m-2 SW radiation upward (reflected) surface clear sky XYT     O   A1a38
rss
surface_net_downward...
..._shortwave_flux
W m-2 SW radiation net surface XYT   O O   A
[rsscs]
[surface_net_downward...
..._shortwave_flux...
.._assuming_clear_sky]
W m-2 SW radiation net surface clear sky XYT   O O   A
rsdt
toa_incoming...
..._shortwave_flux
W m-2 SW radiation downward TOA
(ONLY 1 seasonal cycle is needed)
XY-1     O   A1a29
rsut
toa_outgoing...
..._shortwave_flux
W m-2 SW radiation upward TOA XYT     O   A1a30
rsutcs
toa_outgoing...
..._shortwave_flux...
..._assuming_clear_sky
W m-2 SW radiation upward TOA clear sky XYT     O   A1a41
rst
toa_net_downward...
..._shortwave_flux
W m-2 SW radiation net TOA XYT   O O   A
[rstcs]
[toa_net_downward...
..._shortwave_flux...
.._assuming_clear_sky]
W m-2 SW radiation net TOA clear sky XYT   O O   A
rlds
surface_downwelling...
..._longwave_flux...
..._in_air
W m-2 LW radiation downward surface XYT     O   A1a11
A2a8
A3_6
rldscs
surface_downwelling...
..._longwave_flux...
..._in_air...
..._assuming_clear_sky
W m-2 LW radiation downward surface clear sky XYT     O   A1a39
rlus
surface_upwelling...
..._longwave_flux...
..._in_air
W m-2 LW radiation upward surface XYT     O   A1a12
A2a9
A3_7
rls
surface_net_downward...
..._longwave_flux
W m-2 LW radiation net surface XYT   O O   A
[rlscs]
[surface_net_downward...
..._longwave_flux...
.._assuming_clear_sky]
W m-2 LW radiation net surface clear sky XYT   O O   A
rlut
toa_outgoing...
..._longwave_flux
W m-2 LW radiation outgoing TOA XYT   O O   A1a31
A2a14
rlutcs
toa_outgoing...
..._longwave_flux...
..._assuming_clear_sky
W m-2 LW radiation outgoing TOA clear sky XYT   O O   A1a40
rtmt
net_downward...
..._radiative_flux...
..._at_top_of...
..._atmosphere_model
W m-2 Net radiation at model top XYT     O   A1a32
Number of variables: 59
Estimated database size
DA: 4    DA-3D-1-850: 1    DA-3D-1-500: 2    DA-3D-2-850-200: 2    DA-3D-2-850-500: 1     7312.5 Mb / 50 year(s)
MO: 30    MO-3D-3: 6    MO-fixed: 3     1800.1 Mb / 100 year(s)
SE: 48    SE-3D-17: 8     69.0 Mb
DB STORAGE REQUIRED = 9.0 Gb
 

Atmosphere variables required by specific studies, but NOT SAVED IN THE PMIP 2 DB

These variables require a lot of storage space and will not be stored in the PMIP 2 database, at least not at the beginning of the project. Each group should tell if they will be able to provide this data for about YY years of experience, and keep them in their lab until the data is needed.

High frequency atmosphere variables required by the Dust Model

The variables required at sub-daily timesteps are needed by an offline dust model to validate MPI-BGC LGM experiments.

The required atmosphere variables are: orog, ts, pr, prc, cl, clt, snc, uvas (this name, for surface wind speed, may change), ua, va, ps, evs, tas, ta, hus and FPAR.

The required vegetation variable is: mrso.

For the sub-daily values, indicated frequencies are the acceptable frequencies, the ideal frequencies being twice the accepted ones (e.g. when 6-hourly is acceptable and will work, 3-hourly would be ideal).

The fields should be saved for at least 10 model years, for OA and OAV simulations it might be better to have 20 years. To avoid getting data for some decadal-type anomaly, we could randomly sample the model years during the analytical period.

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.

Note that the dust model also requires one variable from the vegetation variables: mrso.

Please get in touch with Sandy Harrison if you want more details about this!

Name(s) Units Description Axes Frequency DB
DA MO SE AN
ta K Air temperature XYPT P17!       A
tas K 2m?/1.5m? air temperature XYT O!       A
ts K Ground surface temperature (surface skin temperature?) XYT O       A
prc kg m-2 s-1 Convective precipitation XYT O!       A
evs kg m-2 s-1 Surface evaporation XYT O!       P
cl 100 Cloud cover XYPT P17!       A
clt 100 Total cloud cover XYT O       A
snc 100 Snow cover XYT O       A
ps Pa Surface pressure XYT O!       A
hus kg kg-1 Specific humidity XYPT P17!       A
[uvas]
[wind_speed]
m s-1 Surface wind speed (10m) XYT O!!        
ua m s-1 Eastward wind XYPT P17!       A
va m s-1 Northward wind XYPT P17!       A
[fpar]
[fraction_photosynthetic_active_radiation]
1 Fraction of Photosynthetic Active Radiation
for OAV models with prognostic vegetation (better define: SW rad below 690 nm?)
XYT O O      
Number of variables: 14
Estimated database size
DA: 4    DA-12h: 4    DA-6h: 1    DA-3D-17-12h: 5     104625.0 Mb / 50 year(s)
MO: 1     37.5 Mb / 100 year(s)
DB STORAGE REQUIRED = 102.2 Gb
 

High frequency atmosphere variables required by the NCAR Regional Model

The following table lists the variables that are required at sub-DAily frequency (at least two times daily : noon and midnight) by the NCAR RegCM regional climate model. The orography is also required, but it can be found in the regular variables of the PMIP 2 database.

Note that the RegCM model also requires a variables from the ocean variables: tos.

Please get in touch with Noah Diffenbaugh if you want more details about this!

Name(s) Units Description Axes Frequency DB
DA MO SE AN
ts K Ground surface temperature (surface skin temperature?) XYT O!       A
ta K Air temperature XYPT P17!       A
hus kg kg-1 Specific humidity XYPT P17!       A
zg m Geopotential height XYPT P17!       A
ps Pa Surface pressure XYT O       A
ua m s-1 Eastward wind XYPT P17!       A
va m s-1 Northward wind XYPT P17!       A
Number of variables: 7
Estimated database size
DA: 1    DA-12h: 1    DA-3D-17-12h: 5     97312.5 Mb / 50 year(s)
DB STORAGE REQUIRED = 95.0 Gb
 

Rejected variables

Name(s) Units Description Axes Frequency DB
DA MO SE AN
vorpot 1 Potential vorticity on pressure levels XYPT          
uvas ? m s-1 Surface wind speed (10m) XYT          
uaq ? kg m-1 s-1 ? Eastward moisture transport XYPT          
vaq ? kg m-1 s-1 ? Northward moisture transport XYPT          
uacptazg ? W m-1 ? Eastward dry transport (cp.T +zg).u XYPT          
vacptazg ? W m-1 ? Northward dry transport (cp.T +zg).v XYPT          
tauugwd N m-2 GWD induced eastward surface wind stress (positive for eastward wind) XYT         A1
tauvgwd N m-2 GWD induced northward surface wind stress (positive for northward wind) XYT         A1
torts N m-1 Total surface torque (including mountain torque) XYT         A1
moa kg s-1 Total relative angular momentum (per unit area) XYT         A1
[mfs]
[???]
kg m-2 s-1 Surface-atmosphere turbulent moisture flux
(positive upwards)
XYT   O O    
Number of variables: 11
Estimated database size
MO: 1     37.5 Mb / 100 year(s)
SE: 1     0.4 Mb
DB STORAGE REQUIRED = 0.0 Gb
 
Variables moved to the Ocean Variables' list
tauu N m-2 Eastward surface wind stress (positive for eastward wind) XYT         A
tauv N m-2 Northward surface wind stress (positive for northward wind) XYT         A
Number of variables: 2
Variables moved to the Land-surface and vegetation Variables' list
rlength m Surface roughness length for turbulent heat and moisture fluxes
(XY+T if veget varies)
XY          
soiltemp K Average layer soil temperature XYT         G
fdepth m Frozen soil depth XYT         G
tdepth m Depth to soil thaw XYT         G
evap kg m-2 s-1 Total evapotranspiration XYT         G
potevap kg m-2 s-1 Potential evapotranspiration XYT         G
mrso kg m-2 Soil moisture (in the top meter? at root depth?) XYT         A
mrros kg m-2 s-1 Surface runoff rate XYT         A
mrro kg m-2 s-1 Total runoff rate (including drainage) XYT         A
Number of variables: 9

Notes

Michel Crucifix

At the Hadley Centre, we are not in a position to provide Potential Evapotranspiration for the time being. It is necessary to know whether this is an absolutely necessary variable for Sandy's model.

To be discussed:

XYZT fields in sub-daily mode will take a lot of place. I propose to provide them for the last year, only. A climatological year wouldn't be helpful because this would smooth out the extreme events.

Also, I would urge people to review the need for daily outputs (this may be useful for some studies, e.g. storm tracks). Can we decide to provide the daily outputs of all suggested fields for the last 5 years, only?

Rough estimate:

X * Y * Z = in HadAM3 about 131 K
one data = 2 bytes ==> 1 3-D field for one timestep = 262 Kb
6 3-D fields for one time step = 1.5 Mb

1 year at 3-hourly frequency = 360 * 8 = 2880 timestep.

2880 timesteps * 10 Mb = 4.3 Gb.... for one model

20 model years = almost 84 Gb my model

Do we have that much space? 20 years at daily frequency = 10.5 Gb

20 years at monthly frequency = 360 Mb

20 years sat seasonal frequency = 72 Mb

20 years at annual frequency = 30 Mb


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