LDAS Meeting Minutes

May 5^th, 2000, NASA-GSFC

 

 

• Next LDAS Meeting set for 1pm on 6/9/00 at NCEP
• NASA Update:
• Model driver now includes Mosaic, Catchment and CLM models.
• 4 year data archive construction is almost complete. Archive includes ETA/EDAS data, Pinker and Higgins radiation data, StageIV and gauge precipitation data and NCEP hourly forcing data (not all data sources are available back to 1996).
• Announced upgrade to web site planned for June through August time frame. Will include enhanced Image Generator and will feature output from all available LDAS models.
• Mosaic is now installed on the NCEP SGI108 server and can run there in real-time along with NOAH and VIC models.
• NASA will start archiving GOES precipitation and NOHRSC data.
• NASA will post list of common model output variables on web.
• Princeton Update:
• Working on new VIC model driver. NASA will travel to Princeton to help with new driver.
• New Alpha machine will be purchased in near future for use with LDAS modeling effort.
• Validation effort is proceeding.
• Humidities above 100% have been discovered in NCEP hourly forcing data.
• Rutgers Update:
• Trying to obtain more Oklahoma Mesonet data. Current OK Mesonet data holdings are available at http://climate.envsci.rutgers.edu/luo/research/LDAS/okmesonet.html
• Have soil water retention curves for 1998-1999. 2000 data is not yet available.
• ARM data has been obtained.
• Would like to start using/analyzing LDAS model output.
• Alan Robock now a co-editor of JGR. Special edition centered on soil moisture (LDAS) was suggested.
• OH Update:
• Snow model is being integrated into Sacramento model.
• CD-Roms with water year 1998 are available and contain streamflow data.
• Yun will give Washington's data to NASA, and NASA will load data up onto hard disk.
• John is currently working with Wayne Higgins on precipitation analysis.
• Wayne will start performing analysis at 1/8^th degree and wants to use climatological prism analysis.
• NCEP Update:
• Urged three groups to run real-time LSM simulations on NCEP SGI108 server.
• Mosaic will definitely run on SGI, Catchment model and CLM are questionable because of space requirements. Tests will have to be performed to determine how much space output from these models will take up.
• VIC and Mosaic are now running in a real-time fashion at NCEP.
• NCEP will work with NASA to take binary output and convert it into GRIB format.
• NASA will work with NCEP to create NCEP-Hourly forcing files from 1996 through the present.
• Ken met with Dan Tarpley about problems with NESDIS radiation product. Plots of observed versus GOES surface radiation were shown. Improvements were evident, although problems still exist.
• NCEP switched back to using NESDIS GOES product in NCEP hourly forcing files as of February 22^nd, 2000.
• Common model outputs from all LDAS models are needed. 1 GRIB file (per hour?) for each model will be stored at NCEP. This file will contain 15 or so common model output variables and possibly some model-specific output fields.
• List of Common Output Variables:

 

1. State Variables

Surface total soil moisture (mm H2O/mm soil) (top 10 cm)

Surface plant-available soil moisture (mm H2O/mm soil) (top 10 cm)

Volumetric Soil Moisture (mm H2O/mm soil) (every layer) (total: liquid plus

frozen)

Volumetric Soil Ice (mm H2O/mm soil) (every layer)

Plant-available Volumetric Soil Moisture (mm H2O/mm soil) (every layer)

(total: liquid plus frozen)

Snow Water Equivalent (mm) (total snow pack, not layer by layer)

Snow Depth (mm) (Snow density can be derived from snow depth and water

equivalent)

Total column subsurface water (mm) (liquid plus frozen)

Total column plant-available subsurface water (mm) (liquid plus frozen)

Canopy Water (mm) (total: liquid plus frozen)

Canopy temperature (K)

Skin Temperature [consistent with upward longwave values] (K)

Soil Temperature (K) (every layer)

 

2. Energy Fluxes (Hourly Mean Values)

Downward Solar Radiation (W/m2)

Upward Solar Radiation (W/m2)

Downward Longwave Radiation (W/m2)

Upward Longwave Radiation (W/m2)

Latent Heat Flux (W/m2)

Sensible Heat Flux (W/m2)

Ground Heat Flux (W/m2)

Snow Phase Change Heat Flux (W/m2)

 

3. Surface Resistances

Canopy Conductance (m/s)

Soil Resistance (s/m)

Aerodynamic Resistance (s/m)

 

4. Water Fluxes

Precipitation (mm)

Snowmelt (mm)

Potential Evaporation (mm)

Total Evaporation

Direct Evaporation (mm) (bare soil)

Snow evaporation (mm)

Transpiration (mm) (from inside vegetation)

Canopy Evaporation (mm) (from surface of vegetation)

Surface Runoff (mm)

Base-flow (mm)

 

5. Other

Snow fraction (on ground, on canopy)

Albedo

Bare soil

Snow

Total

Snow age