6.32. fire.nml

This file contains two namelists one called JULES_FIRE_WEATHER_INDEX that contains switches used to calculate the different fire weather indices available. The second namelist is for parameters associated with the inferno fire model called JULES_INFERNO

6.32.1. JULES_FIRE_WEATHER_INDEX namelist members

JULES_FIRE_WEATHER_INDEX::l_fire_weather_index

Type:

logical

Default:

F

Switch to enable the fire module.

TRUE

The fire module will be executed according to the settings of subsequent namelist members.

FALSE

The fire module will not be executed and subsequent members of the namelist will have no effect.

JULES_FIRE_WEATHER_INDEX::mcarthur_flag

Type:

boolean

Default:

F

Switch for calculating the McArthur Forest Fire Danger Index (FFDI).

JULES_FIRE_WEATHER_INDEX::mcarthur_opt

Type:

real

Default:

MDI

Switch for choosing which method of calculating the soil moisture deficit required for the McArthur Forest Fire Danger Index (FFDI). 1 uses the model soil moisture, 2 uses a fixed value of 120 mm.

JULES_FIRE_WEATHER_INDEX::canadian_flag

Type:

boolean

Default:

F

Switch for calculating the Canadian Fire Weather Index (FWI).

JULES_FIRE_WEATHER_INDEX::canadian_hemi_opt

Type:

boolean

Default:

F

If TRUE, then the month-dependent parameters used in the calculation will be offset by 6 months for the southern hemisphere. This will cause a discontinuity in results when crossing the equator.

JULES_FIRE_WEATHER_INDEX::nesterov_flag

Type:

boolean

Default:

F

Switch for calculating the Nesterov Index.

6.32.2. JULES_INFERNO namelist members

JULES_INFERNO::z_burn_max

Type:

real

Default:

0.2

Parameter controlling the depth to which fire burns soil litter carbon in metres. At depths shallower than this value, the fire can burn soil carbon in the two litter pools (dpm and rpm). If z_burn_max falls within a layer only a proportion of the soil carbon is burnt. Only used with layered soil carbon scheme (l_layeredc = TRUE) and fire (both l_trif_fire and l_inferno are TRUE or nml:mem:JULES_VEGETATION::l_inferno is TRUE). In reality the burn depth varies so please check whether the default value of 0.2 is suitable for your application.

JULES_INFERNO::flam_sm_func

Type:

integer

Permitted:

1, 2

Default:

1

Switch used to define the function used to parameterise the relationship between soil moisture and flammability

1. A linear relationship which has a flammability of 0 at saturation and 1 when soil is completely dry.

2. An exponential relationship controlled by flam_sm_low and flam_sm_up

JULES_INFERNO::flam_sm_low

Type:

real

Default:

0.0

Soil moisture below which flammability is 1.0. Expressed as a fraction of saturation. Only used if flam_sm_func = 2.

JULES_INFERNO::flam_sm_up

Type:

real

Default:

2.4

Exponential decay parameter for relationship between soil moisture and flammability. Only used if flam_sm_func = 2.

JULES_INFERNO::flam_rhum_low

Type:

real

Default:

10.0

Lower relative humidity threshold for relationship between relative humidity and flammability below which value of flammability is 1.0. Expressed as a percentage.

JULES_INFERNO::flam_rhum_up

Type:

real

Default:

90.0

Upper relative humidity threshold for relationship between relative humidity and flammability above which value of flammability is 0.0. Expressed as a percentage.

JULES_INFERNO::flam_rain_const

Type:

real

Default:

14929920000.0

An exponential decay factor that defines the relationship between flammability and rainfall. In order to recreate the relationship hardwired into JULES version 8.2 and lower this value should be set to 14929920000.0. However, this is not the relationship that was documented by Mangeon et al. (2016). If you want the Mangeon et al. relationship then this value should be 172800.0. If you want to remove the dependence of flammability on rainfall then this value should be set to 0.0.

See also

References:

• Mangeon, S., Voulgarakis, A., Gilham, R., Harper, A., Sitch, S., and Folberth, G.: INFERNO: a fire and emissions scheme for the UK Met Office’s Unified Model, Geosci. Model Dev., 9, 2685-2700, https://doi.org/10.5194/gmd-9-2685-2016, 2016.

JULES_INFERNO::flam_fuel_low

Type:

real

Default:

0.02

Lower fuel load threshold for flammability

JULES_INFERNO::flam_fuel_up

Type:

real

Default:

0.2

Upper fuel load threshold for flammability

JULES_INFERNO::ccdpm_min

Type:

real

Default:

0.8

Minimum DPM soil carbon pool combustion completeness fraction.

JULES_INFERNO::ccdpm_max

Type:

real

Default:

1.0

Maximum DPM soil carbon pool combustion completeness fraction.

JULES_INFERNO::ccrpm_min

Type:

real

Default:

0.0

Minimum RPM soil carbon pool combustion completeness fraction.

JULES_INFERNO::ccrpm_max

Type:

real

Default:

0.2

Maximum RPM soil carbon pool combustion completeness fraction.