Lapse Rate Based Temperature Downscaling
- Author: O.Conrad (c) 2021
- Menu: Climate and Weather | Temperature
Description
The Lapse Rate Based Temperature Downscaling is quite simple, but might perform well for mountainous regions, where the altitudinal gradient is the main driver for local temperature variation. First, a given lapse rate is used to estimate sea level temperatures from elevation and temperature data at a coarse resolution. Second, the same lapse rate is used to estimate the terrain surface temperature using higher resoluted elevation data and the spline interpolated sea level temperatures from the previous step. The lapse rates can be defined as one constant value valid for the whole area of interest, or as varying value as defined by an additional input grid. Alternatively a constant lapse rate can be estimated from the coarse resolution input with a regression analysis.
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Elevation | grid, input | LORES_DEM | - | - |
| Temperature | grid, input | LORES_T | - | - |
| Lapse Rate | grid, input | LORES_LAPSE | - | - |
| Elevation | grid, input | HIRES_DEM | - | - |
| Output | Sea Level Temperature | grid, output, optional | LORES_SLT | - | - |
| Temperature | grid, output | HIRES_T | - | - |
| Regression Summary | table, output, optional | REGRS_SUMMARY | - | - |
| Options | Coarse Resolution | grid system | LORES_GRID_SYSTEM | - | - |
| High Resolution | grid system | HIRES_GRID_SYSTEM | - | - |
| Lapse Rate | choice | LAPSE_METHOD | - | Available Choices:
[0] constant lapse rate
[1] constant lapse rate from regression
[2] varying lapse rate from grid
Default: 1 |
| Regression | choice | REGRS_LAPSE | - | Available Choices:
[0] elevation
[1] elevation and position
[2] elevation and position (2nd order polynom)
Default: 2 |
| Limit Minimum Lapse Rate | boolean | LIMIT_LAPSE | If set, lapse rates from regression are limited to a minimum as specified by the constant lapse rate parameter. | Default: 0 |
| Constant Lapse Rate | floating point number | CONST_LAPSE | Constant lapse rate in degree of temperature per 100 meter. | Default: 0.600000 |
Command Line
Usage: saga_cmd climate_tools 30 [-LORES_DEM ] [-LORES_T ] [-LORES_LAPSE ] [-LORES_SLT ] [-HIRES_DEM ] [-HIRES_T ] [-LAPSE_METHOD ] [-REGRS_SUMMARY ] [-REGRS_LAPSE ] [-LIMIT_LAPSE ] [-CONST_LAPSE ]
-LORES_DEM: Elevation
grid, input
-LORES_T: Temperature
grid, input
-LORES_LAPSE: Lapse Rate
grid, input
-LORES_SLT: Sea Level Temperature
grid, output, optional
-HIRES_DEM: Elevation
grid, input
-HIRES_T: Temperature
grid, output
-LAPSE_METHOD: Lapse Rate
choice
Available Choices:
[0] constant lapse rate
[1] constant lapse rate from regression
[2] varying lapse rate from grid
Default: 1
-REGRS_SUMMARY: Regression Summary
table, output, optional
-REGRS_LAPSE: Regression
choice
Available Choices:
[0] elevation
[1] elevation and position
[2] elevation and position (2nd order polynom)
Default: 2
-LIMIT_LAPSE: Limit Minimum Lapse Rate
boolean
Default: 0
-CONST_LAPSE: Constant Lapse Rate
floating point number
Default: 0.600000