A fire model with distinct crop, pasture, and non-agricultural burning: use of new data and a model-fitting algorithm for FINAL.1
This study describes and evaluates the Fire Including Natural & Agricultural Lands model (FINAL) which, for the first time, explicitly simulates cropland and pasture management fires separately from non-agricultural fires. The non-agricultural fire module uses empirical relationships to...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2018-03-01
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Series: | Geoscientific Model Development |
Online Access: | https://www.geosci-model-dev.net/11/815/2018/gmd-11-815-2018.pdf |
Summary: | This study describes and evaluates
the Fire Including Natural & Agricultural Lands model (FINAL) which, for the
first time, explicitly simulates cropland and pasture management fires
separately from non-agricultural fires. The non-agricultural fire module uses
empirical relationships to simulate burned area in a quasi-mechanistic
framework, similar to past fire modeling efforts, but with a novel
optimization method that improves the fidelity of simulated fire patterns to
new observational estimates of non-agricultural burning. The agricultural
fire components are forced with estimates of cropland and pasture fire
seasonality and frequency derived from observational land cover and satellite
fire datasets. FINAL accurately simulates the amount, distribution, and
seasonal timing of burned cropland and pasture over 2001–2009 (global
totals: 0.434×10<sup>6</sup> and 2.02×10<sup>6</sup> km<sup>2</sup> yr<sup>−1</sup>
modeled, 0.454×10<sup>6</sup> and 2.04×10<sup>6</sup> km<sup>2</sup> yr<sup>−1</sup>
observed), but carbon emissions for cropland and pasture fire are
overestimated (global totals: 0.295 and 0.706 PgC yr<sup>−1</sup> modeled,
0.194 and 0.538 PgC yr<sup>−1</sup> observed). The non-agricultural fire
module underestimates global burned area (1.91×10<sup>6</sup> km<sup>2</sup> yr<sup>−1</sup> modeled, 2.44×10<sup>6</sup> km<sup>2</sup> yr<sup>−1</sup>
observed) and carbon emissions (1.14 PgC yr<sup>−1</sup> modeled,
1.84 PgC yr<sup>−1</sup> observed). The spatial pattern of total burned area
and carbon emissions is generally well reproduced across much of sub-Saharan
Africa, Brazil, Central Asia, and Australia, whereas the boreal zone sees
underestimates. FINAL represents an important step in the development of
global fire models, and offers a strategy for fire models to consider
human-driven fire regimes on cultivated lands. At the regional scale,
simulations would benefit from refinements in the parameterizations and
improved optimization datasets. We include an in-depth discussion of the
lessons learned from using the Levenberg–Marquardt algorithm in an
interactive optimization for a dynamic global vegetation model. |
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ISSN: | 1991-959X 1991-9603 |