Overview
The PRISMA tool includes scripts and driving files to run global, regional, and local simulations with the CHTESSEL land surface scheme on any period within 1979-2012 including meteorological forcing extraction (from the EartH2Observe Threadds server for WRR1) available at 0.5x0.5 degrees resolution (or 0.25x0.25 for the latest WRR2) and can be combined with simple offline nudging, OI or simplified EKF schemes.
The documentation on CHTESSEL land surface scheme is available as Chapter 8 of the Integrated Forecasting System Documentation (http://www.ecmwf.int/en/forecasts/documentation-and-support/changes-ecmwf-model/ifs-documentation). The CHTESSEL source code with the compilation script is available as with OpenIFS (internally as 41r1/43r1 branch) (see Offline Surface Model User Guide for instructions).
The gfortran compiler and "netcdf" library (with support of NetCDF4) are needed for compilation and "nco" for file handling in the scripts.
Meteorological forcing
The Meteorological forcing are prepared starting from ERA-Interim and with bias correction methods for ingesting further ground-based observations that were not assimilated in ERA-Interim. The data are in Netcdf4 and made available via the Water Cycle Integrator data portal, info at https://wci.earth2observe.eu.
The publication describing the data processing over land is available at http://onlinelibrary.wiley.com/doi/10.1002/2014WR015638/abstract.
The dataset combines Watch Forcing Dataset ERA-Interim (WFDEI) over land with a GPCPv2.2-corrected precipitation over water points, and obtain globally contiguous land, lakes and ocean corrected meteorological fields (with 720x360 grid-points, corresponding to 0.5 degrees resolution). The data are made discoverable on the EartH2Observe project web-server: http://wci.earth2observe.eu/thredds/catalog.html
Land surface initial conditions
The files "surfinit.nc" and "surfclim.nc" contain initial and physiography information that come from the operational IFS model version (in its latest operational cycle 40R1) in a resolution very close to the regular 0.5x0.5 degrees grid (the T511 Gaussian reduced grid) and using a nearest neighbour method to associate values so there is not really any interpolation done on the original fields values.
For surfclim.nc the list of variables are reported below. for surfinit see o_gg.nc table below.
| Variable | Description | Units |
|---|---|---|
lat lon month landsea CLAKE LDEPTH Mask Malbedo Mlail Mlaih z0m lz0h geopot cvl cvh tvl tvh sotype sdor sst seaice | latitude longitude month index fraction of land fraction of lakes depth of lakes mask monthly albedo monthly lai low vegetation monthly lai high vegetation roughness length for momentum roughness length for heat (log) surface geopotential (for Z) Low vegetation cover fraction High vegetation cover fraction Low vegetation cover type High vegetation cover type Soil type Standard deviation of subgrid orography sea surface temperature sea ice cover | degrees_north degrees_east 1 to 12 0 to 1 0 to 1 m 0 to 1 0 to 1 m2/m2 m2/m2 m m m2/s2 0 to 1 0 to 1 0 to 20 0 to 20 0 to 7 m K 0 to 1 |
Land surface simulations
This package contains the scripts to subset and run CHTESSEL at any given location (point or area) and any date 1979-2012.
The EartH2Observe global meteorological forcing (1979-2012) and the initial conditions and climate fields at 0.5x0.5 permits to run a number of cases by subsetting the area and period of interest.
The script "subset_E2OBS_Land_init.ksh" generates climate fields and initial conditions on a user defined single point or a domain (examples for France-AROME and CONUS are in the scripts)
The script "subset_E2OBS_Met_forcing.ksh" generates the meteorological forcing on a user defined single point or domain and on any duration from one day to one year.
The script "run_E2OBS_daily.ksh" runs the offline land surface model in daily chunks with restart on any duration from one day to one year. Perturbed runs (e.g. with Precipitation=0) can be performed.
Land surface output
The output of the simulation is organized in different files: o_gg.nc, o_ggd.nc, o_sus.nc, o_wat.nc, o_cld.nc, o_d2m.nc, o_efl.nc, o_eva.nc, o_fix.nc.
o_gg.nc (o_ggd.nc) contains the CHTESSEL prognostic variables (and its daily average):
Variable | Description | Unit |
|---|---|---|
lat lon nlevs tile vtype time timestp AvgSurfT CanopInt SWE SnowT SAlbedo snowdens TLICE TLMNW TLWML TLBOT TLSF HLICE HLML SoilMoist SoilTemp icetemp | latitude longitude soil level tile number vegetation type number time model time step skin temperature canopy interception depth snow water equivalent snow temperature Snow albedo Snow density lake ice temperature lake mean water temperature lake mixed layer temperature lake bottom temperature lake temperature shape factor lake ice thickness lake mixed layer thickness soil moisture soil temperature sea ice temperature | degrees_north degrees_east level level level seconds since YYYY-MM-DD - K kg m-2 kg m-2 K - kg m-3 K K K K - m m kg m-2 K K |
The other o_*.nc files contains complementary ancillary or diagnostic fields.
Land surface assimilation
The assimilation is under development within the H-SAF and APPLICATE projects. An Optimal Interpolation method has been developed for general use and is documented for the POINT (Portable Observations INTerpolator) toolbox (internal ECMWF only).
Download and use of PRISMA
The scripts and driving files are provided as attachment to this page and under OpenIFS research collaboration agreements.
A working version of the scripts for use at ECMWF (with local file extraction) is available at: /home/pa/pad/public/PRISMA
The Offline Surface Modelling (OSM) driver is available at: /home/pa/pad/public/OSM
1 Comment
Unknown User (nagc)
The file organisation has changed to 1 file per forcing field. eg. for wind
https://wci.earth2observe.eu/thredds/dodsC/ecmwf/met_forcing_v0/wind_3hourly.nc
That makes it easier and faster to subset. The best way to discover data is the WCI portal https://wci.earth2observe.eu/
They made a nice data discovery tool that can be used to search the Thredds server: https://wci.earth2observe.eu/data/group/earth2observe?