Soil Temperature Parameters

This section describes the parameters accepted by MONICA's soil-temperature module. They control the initialization of the soil-temperature profile and the calculation of soil thermal conductivity and volumetric heat capacity.

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List of soil temperature parameters

Parameter Name	Type	Unit	Description	Example
BaseTemperature	Number	°C	Temperature used to initialize the deepest model layer. Together with InitialSurfaceTemperature, it defines the initial temperature profile through the soil.	"BaseTemperature": 9.5
InitialSurfaceTemperature	Number	°C	Initial soil-surface temperature. The model interpolates between this value and BaseTemperature to initialize the temperature of the soil layers.	"InitialSurfaceTemperature": 10
DensityAir	Number	kg m-3	Air density used when calculating the volumetric heat capacity of air-filled pore space	"DensityAir": 1.25
SpecificHeatCapacityAir	Number	J kg-1 K-1	Specific heat capacity of air used in the soil heat-capacity calculation	"SpecificHeatCapacityAir": 1005
DensityHumus	Number	kg m-3	Density assigned to the soil organic matter fraction for the heat-capacity calculation	"DensityHumus": 1300
SpecificHeatCapacityHumus	Number	J kg-1 K-1	Specific heat capacity assigned to the soil organic matter fraction	"SpecificHeatCapacityHumus": 1920
DensityWater	Number	kg m-3	Density of water used in heat capacity calculations	"DensityWater": 1000
SpecificHeatCapacityWater	Number	J kg-1 K-1	Specific heat capacity of water	"SpecificHeatCapacityWater": 4192
QuartzRawDensity	Number	kg m-3	Density assigned to the mineral soil fraction in the heat-capacity calculation	"QuartzRawDensity": 2650
SpecificHeatCapacityQuartz	Number	J kg-1 K-1	Specific heat capacity assigned to the mineral soil fraction	"SpecificHeatCapacityQuartz": 750
NTau	Number		Empirical scaling factor applied to the effective volume and heat storage of the temperature layers. It influences how quickly soil temperatures respond to surface-temperature changes.	"NTau": 0.65
SoilAlbedo	Number		Nominal fraction of incoming solar radiation reflected by the soil surface. A value of 0 represents complete absorption and 1 complete reflection. This parameter is parsed and serialized but is not currently used by the soil-temperature calculation.	"SoilAlbedo": 0.7
SoilMoisture	Number	m3 m-3	Constant volumetric soil-water content used when calculating thermal conductivity and heat capacity. The soil-temperature module does not currently use the dynamically simulated water content of individual soil layers for these calculations.	"SoilMoisture": 0.25
type	String		Declares that this JSON defines soil temperature module parameters	"type": "UserSoilTemperatureParameters"

Note

Parameters provided as arrays (e.g., [1.25, "kg/m3"]) contain a value and a unit string. The unit string is for documentation purposes only and is not interpreted by the model.

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Example: soil-temperature.json

{
    "BaseTemperature": 9.5,
    "InitialSurfaceTemperature": 10,

    "DensityAir": [1.25, "kg/m3"],
    "SpecificHeatCapacityAir": [1005, "J/(kg*K)"],

    "DensityHumus": [1300, "kg/m3"],
    "SpecificHeatCapacityHumus": [1920, "J/(kg*K)"],

    "DensityWater": [1000, "kg/m3"],
    "SpecificHeatCapacityWater": [4192, "J/(kg*K)"],

    "QuartzRawDensity": [2650, "kg/m3"],
    "SpecificHeatCapacityQuartz": [750, "J/(kg*K)"],

    "NTau": 0.65,
    "SoilAlbedo": 0.7,
    "SoilMoisture": 0.25,

    "type": "SoilTemperatureModuleParameters"
}