Tool Bioclimatic Variables
This tool calculates biogically meaningful variables from monthly climate data (mean, minimum and maximum temperature and precipitation), as provided e.g. by the WorldClim - Global Climate Data project.
The implementation follows the definitions given by Jeremy van der Wal at BioClim - Bioclimatic Variables:
- Annual Mean Temperature: The mean of all the monthly mean temperatures. Each monthly mean temperature is the mean of that month's maximum and minimum temperature.
- Mean Diurnal Range: The annual mean of all the monthly diurnal temperature ranges. Each monthly diurnal range is the difference between that month's maximum and minimum temperature.
- Isothermality: The mean diurnal range (parameter 2) divided by the annual temperature range (parameter 7).
- Temperature Seasonality: returns either
- the temperature coefficient of variation as the standard deviation of the monthly mean temperatures expressed as a percentage of the mean of those temperatures (i.e. the annual mean). For this calculation, the mean in degrees Kelvin is used. This avoids the possibility of having to divide by zero, but does mean that the values are usually quite small.
- the standard deviation of the monthly mean temperatures.
- Maximum Temperature of Warmest Period: The highest temperature of any monthly maximum temperature.
- Minimum Temperature of Coldest Period: The lowest temperature of any monthly minimum temperature.
- Temperature Annual Range: The difference between the Maximum Temperature of Warmest Period and the Minimum Temperature of Coldest Period.
- Mean Temperature of Wettest Quarter: The wettest quarter of the year is determined (to the nearest month), and the mean temperature of this period is calculated.
- Mean Temperature of Driest Quarter: The driest quarter of the year is determined (to the nearest month), and the mean temperature of this period is calculated.
- Mean Temperature of Warmest Quarter: The warmest quarter of the year is determined (to the nearest month), and the mean temperature of this period is calculated.
- Mean Temperature of Coldest Quarter: The coldest quarter of the year is determined (to the nearest month), and the mean temperature of this period is calculated.
- Annual Precipitation: The sum of all the monthly precipitation estimates.
- Precipitation of Wettest Period: The precipitation of the wettest month.
- Precipitation of Driest Period: The precipitation of the driest month.
- Precipitation Seasonality: The Coefficient of Variation is the standard deviation of the monthly precipitation estimates expressed as a percentage of the mean of those estimates (i.e. the annual mean).
- Precipitation of Wettest Quarter: The wettest quarter of the year is determined (to the nearest month), and the total precipitation over this period is calculated.
- Precipitation of Driest Quarter: The driest quarter of the year is determined (to the nearest month), and the total precipitation over this period is calculated.
- Precipitation of Warmest Quarter: The warmest quarter of the year is determined (to the nearest month), and the total precipitation over this period is calculated.
- Precipitation of Coldest Quarter: The coldest quarter of the year is determined (to the nearest month), and the total precipitation over this period is calculated.
The quarterly parameters are not aligned to any calendar quarters. BioClim's definition of a quarter is any consecutive 3 months. For example, the driest quarter will be the 3 consecutive months that are drier than any other set of 3 consecutive months.
- Author: O.Conrad (c) 2016
- Menu: Climate|Bioclimatology
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Mean Temperature | Grid list (input) | TMEAN | - | - |
| Minimum Temperature | Grid list (input) | TMIN | - | - |
| Maximum Temperature | Grid list (input) | TMAX | - | - |
| Precipitation | Grid list (input) | P | - | - |
| Output | Annual Mean Temperature | Grid (output) | BIO_01 | - | - |
| Mean Diurnal Range | Grid (output) | BIO_02 | - | - |
| Isothermality | Grid (output) | BIO_03 | - | - |
| Temperature Seasonality | Grid (output) | BIO_04 | - | - |
| Maximum Temperature of Warmest Month | Grid (output) | BIO_05 | - | - |
| Minimum Temperature of Coldest Month | Grid (output) | BIO_06 | - | - |
| Temperature Annual Range | Grid (output) | BIO_07 | - | - |
| Mean Temperature of Wettest Quarter | Grid (output) | BIO_08 | - | - |
| Mean Temperature of Driest Quarter | Grid (output) | BIO_09 | - | - |
| Mean Temperature of Warmest Quarter | Grid (output) | BIO_10 | - | - |
| Mean Temperature of Coldest Quarter | Grid (output) | BIO_11 | - | - |
| Annual Precipitation | Grid (output) | BIO_12 | - | - |
| Precipitation of Wettest Month | Grid (output) | BIO_13 | - | - |
| Precipitation of Driest Month | Grid (output) | BIO_14 | - | - |
| Precipitation Seasonality | Grid (output) | BIO_15 | - | - |
| Precipitation of Wettest Quarter | Grid (output) | BIO_16 | - | - |
| Precipitation of Driest Quarter | Grid (output) | BIO_17 | - | - |
| Precipitation of Warmest Quarter | Grid (output) | BIO_18 | - | - |
| Precipitation of Coldest Quarter | Grid (output) | BIO_19 | - | - |
| Options | Grid system | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Temperature Seasonality | Choice | SEASONALITY | - | Available Choices:
[0] Coefficient of Variation
[1] Standard Deviation
Default: 1 |
Command-line
Usage: saga_cmd climate_tools 10 [-TMEAN <str>] [-TMIN <str>] [-TMAX <str>] [-P <str>] [-BIO_01 <str>] [-BIO_02 <str>] [-BIO_03 <str>] [-BIO_04 <str>] [-BIO_05 <str>] [-BIO_06 <str>] [-BIO_07 <str>] [-BIO_08 <str>] [-BIO_09 <str>] [-BIO_10 <str>] [-BIO_11 <str>] [-BIO_12 <str>] [-BIO_13 <str>] [-BIO_14 <str>] [-BIO_15 <str>] [-BIO_16 <str>] [-BIO_17 <str>] [-BIO_18 <str>] [-BIO_19 <str>] [-SEASONALITY <str>]
-TMEAN:<str> Mean Temperature
Grid list (input)
-TMIN:<str> Minimum Temperature
Grid list (input)
-TMAX:<str> Maximum Temperature
Grid list (input)
-P:<str> Precipitation
Grid list (input)
-BIO_01:<str> Annual Mean Temperature
Grid (output)
-BIO_02:<str> Mean Diurnal Range
Grid (output)
-BIO_03:<str> Isothermality
Grid (output)
-BIO_04:<str> Temperature Seasonality
Grid (output)
-BIO_05:<str> Maximum Temperature of Warmest Month
Grid (output)
-BIO_06:<str> Minimum Temperature of Coldest Month
Grid (output)
-BIO_07:<str> Temperature Annual Range
Grid (output)
-BIO_08:<str> Mean Temperature of Wettest Quarter
Grid (output)
-BIO_09:<str> Mean Temperature of Driest Quarter
Grid (output)
-BIO_10:<str> Mean Temperature of Warmest Quarter
Grid (output)
-BIO_11:<str> Mean Temperature of Coldest Quarter
Grid (output)
-BIO_12:<str> Annual Precipitation
Grid (output)
-BIO_13:<str> Precipitation of Wettest Month
Grid (output)
-BIO_14:<str> Precipitation of Driest Month
Grid (output)
-BIO_15:<str> Precipitation Seasonality
Grid (output)
-BIO_16:<str> Precipitation of Wettest Quarter
Grid (output)
-BIO_17:<str> Precipitation of Driest Quarter
Grid (output)
-BIO_18:<str> Precipitation of Warmest Quarter
Grid (output)
-BIO_19:<str> Precipitation of Coldest Quarter
Grid (output)
-SEASONALITY:<str> Temperature Seasonality
Choice
Available Choices:
[0] Coefficient of Variation
[1] Standard Deviation
Default: 1