Reviewing Values in LANDUSE.TBL
Contents
Reviewing Values in LANDUSE.TBL¶
LANDUSE.TBL is used by the land surface model to specify some variables depending on the land surface type. According to the Dudhia WRF Overview presentation [Dudhia, 2014] , the following are used:
VEGPARM.TB - Vegetation properties in Noah and RUC
SOILPARM.TBL - Soil peoperties in Noah and RUC
LANDUSE.TBL - Surface properties in 5-layer model [Dudhia, 1996]
We are using the following in the idealized model¶
5-layer model (use
LANDUSE.TBL)USGS section (specified in
namelist.input)The entire time we have land use category number 24 - snow and ice
Currently for snow and ice in my idealized simulations:¶
Season |
Albedo \((\%)\) |
Suface Moisture Availability \((*100\%)\) |
Surface Emissivity \((\%)\) |
Surface Roughness |
Thermal Inertia Constant |
Snow Cover Effect |
Surface Heat Capacity \((J / (m^{3} K))\) |
Label |
|---|---|---|---|---|---|---|---|---|
Summer |
55. |
.95 |
.95 |
0.1 |
5. |
0. |
9.0e25 |
Snow or Ice |
Winter |
70. |
.95 |
.95 |
0.1 |
5. |
0. |
9.0e25 |
Snow or Ice |
Preliminary observations¶
Albedo is far too low - BUT we have defined this in the namelist so this value is not used.
Surface moisture availability and emissivity could both probably be increased.
Surface roughness could probably be decreased.
Snow cover effects seem to be constant regardless of surface
The thermal inertial constant could probably be improved, but I’m not sure what this is.
Surface heat capacity could be improved.
What variables do we need? Where can we get them?¶
Have¶
Albedo
This is already incorporated into the model
Can Calculate¶
Surface roughness length
This is calculated below and is much lower than that in the table
This could be a good value to adjust
Surface heat capacity
This is calculated below and is much higher than that in the table
I’d like to discuss this variable with Von
Thermal inertia constant
I am struggling with calculating this, I need to do more reading to understand it
Can improve estimations¶
Surface moisture availability
This is higher only in the values above water
The difference is small so it probably would not be a large difference
Emissivity
Also a small difference so likely not a big change