i.eb.deltat

Computes the difference of temperature between surface skin temperature and air temperature at 2m as part of sensible heat flux calculations.

Command linePython (grass.script)

i.eb.deltat [-w] tempk=name delta=name [--verbose] [--quiet] [--qq] [--ui]

Example:

i.eb.deltat tempk=tempk delta=delta

grass.script.run_command("i.eb.deltat", tempk="tempk", delta="delta", flags=None, verbose=False, quiet=False, superquiet=False)

Example:

gs.run_command("i.eb.deltat", tempk="tempk", delta="delta")

Parameters

Command linePython (grass.script)

tempk=name [required]
    Name of the surface skin temperature map [Kelvin]
    Default: tempk
delta=name [required]
    Name of the output delta layer
    Default: delta
-w
    Wim's generic table
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

tempk : str, required
    Name of the surface skin temperature map [Kelvin]
    Used as: input, raster, name
    Default: tempk
delta : str, required
    Name of the output delta layer
    Used as: input, raster, name
    Default: delta
flags : str, optional
    Allowed values: w
    w
        Wim's generic table
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

DESCRIPTION

i.eb.deltat calculates the difference of temperature between two heights. Generally considered between surface skin temperature and air temperature \~2m above the skin (soil/canopy/etc). This approximation is found in Pawan (2004) and is used for initialization of the sensible heat flux iterations in SEBAL (Bastiaanssen, 1995).

NOTES

This is found in Pawan (2004). This is the case of a Landsat satellite image of Oct 8, 2003, located in Portugal. He also mentions a strange equation for MODIS of January 13, 2003. delta T = -3440.37 +12.18404 * LST. Of course the intercept looks like the LST band is still in storage format (*10000). Additionally, it is worth menitoning that Pawan only created this map once, and used it all the time. This is certainly because he created the relationship from some field data and found it reliable enough not to modify this parameter anymore, leading to a simplified iteration process of SEBAL, changing only the rah parameter through the iterations of H,L,psi,rah.

TODO

AUTHOR

Yann Chemin, Asian Institute of Technology, Thailand

SOURCE CODE

Available at: i.eb.deltat source code (history)
Latest change: Thursday Feb 20 13:02:26 2025 in commit 53de819