Impact model: SSiB4/TRIFFID-Fire

ISIMIP3a

Confirm data for simulation round ISIMIP3a

Person responsible for model simulations in this simulation round

Huilin Huang: huilin.huang@pnnl.gov, 0000-0002-7328-6738, PNNL (USA)

Output Data

Experiments: (*) obsclim_histsoc_nofire, obsclim_histsoc_1901co2, obsclim_histsoc_default, counterclim_histsoc_default
Climate Drivers: GSWP3-W5E5
Date: 2022-05-22

Basic information

Model Homepage: https://github.com/hhllbao93/SSiB4-TRIFFID-Fire

Reference Paper: Main Reference: Huang, H., Xue, Y., Li, F., and Liu, Y. et al. Modeling long-term fire impact on ecosystem characteristics and surface energy using a process-based vegetation–fire model SSiB4/TRIFFID-Fire v1.0. Geosci. Model Dev.,13,6029–6050,2020

Reference Paper: Other References: Huilin Huang, Yongkang Xue, Ye Liu, Fang Li, and Gregory S. Okin et al. Modeling the short-term fire effects on vegetation dynamics and surface energy in southern Africa using the improved SSiB4/TRIFFID-Fire model. Geosci. Model Dev.,None,,2021

Resolution

Spatial aggregation: regular grid

Horizontal resolution: 0.5’ x 0.5’

Temporal resolution of input data: climate variables: monthly

Temporal resolution of input data: co2: annual

Temporal resolution of input data: land use/land cover: annual

Temporal resolution of input data: soil: constant

Input data

Observed atmospheric climate data sets used: W5E5v2.0, W5E5v1.0

Socio-economic data sets used: National historical Gross Domestic Product (GDP), National, gridded historical population

Land use data sets used: Historical, gridded land use

Other data sets used: Lightning, Land-sea mask

Climate variables: huss, sfcWind, tas, rlds, rsds, ps, pr

Spin-up

Was a spin-up performed?: Yes

Spin-up design: Spin-up experiments have been done for 1851-1900 using cycling climate forcing from 1901-1910 and transient CO2 conditions

Natural Vegetation

Natural vegetation partition: For each grid, SSiB4/TRIFFID-Fire simulates the fraction of 7 plant functional types (PFTs) + the bare soil: BET: Broadleaf evergreen tree NET: Needleleaf evergreen tree DBT: Deciduous broadleaf tree C3: C3 grass C4: C4 grass SHR: shrub TUN: tundra shrub

Natural vegetation dynamics: In each grid, the fraction of each PFTs is updated every 10 days related to the Net Primary Productivity

Soil layers: 3 layers

Fire-specific input data sets

What input datasets are used in the fire model and what are they used for?: Country level GDP: for calculating human ignition grid level population density: for calculating human ignition lightning: for calculating natural ignition

What is the time step of the fire model?: daily

What is the time step of the exchange between fire and vegetation model? e.g. are carbon pools and cover fractions updated every day?: The carbon pool and cover fractions are updated every 10 days

Burnt Area

What are the main components of burned area computation?: fire on non-agriculture and non-peat land and fire over the peat fire

Ignition

Which sources of ignition are included?: natural + human ignition

Is fire ignition implemented as a random process?: no

How are natural ignitions implemented? which data is used and how is it scaled?: From the lightning data.

Is human influence on fire ignition and/or suppression included? how?: Yes. Human ignition and suppression are both related to population density and GDP

If human ignitions are included for which conditions are the ignitions highest/lowest?: The more population/higher GDP, the more ignition

Spread and duration

How does fire spread?: Fire spread is considered as in elliptical shape

How is fire duration computed?: Assume to be one day

Fuel load and combustion

How does the model compute fuel load?: Leaf+wood+litter of each PFT

List of fuel classes (full names and abbreviations): We consider the leaf, wood, and litter of the following PFTs BET: Broadleaf evergreen tree NET: Needleleaf evergreen tree DBT: Deciduous broadleaf tree C3: C3 grass C4: C4 grass SHR: shrub TUN: tundra shrub

Is fuel moisture linked to soil moisture/air humidity/precip?: Yes. Linked to soil moisture and air humidity

Which carbon pools are combusted?: leaf, wood, and litter

Is the combustion completeness constant or depends on what (fuel type, moisture?): Depending on PFT

Landcover

What is the minimum/maximum burned area fraction at grid cell level? over which time period? : minimum: 0 maximum: 100 over each time step

Is burned area computed separately for each pft? if not how is burned area separated into the pft-burned area? : No. We consider grid-averaged burned conditions for burned area

Are peatland fires included?: yes

Are deforestation or land clearing fires included?: No

How are pastures represented?: It is regarded as natural grassland

If croplands burn, does the fire model differ for this pft? if yes please describe.: no crop fire

If pastures burn, does the fire model differ for his pft? if yes, please describe: no paster fire

Fire mortality

Vegetation fire mortality: is it constant/constant per pft/depends on (for instance fire intensity, bark thickness, veg height): Constant per pft