 |
| Titel |
A process-based fire parameterization of intermediate complexity in a Dynamic Global Vegetation Model |
| VerfasserIn |
F. Li, X. D. Zeng, S. Levis |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 7 ; Nr. 9, no. 7 (2012-07-30), S.2761-2780 |
| Datensatznummer |
250007199
|
| Publikation (Nr.) |
 copernicus.org/bg-9-2761-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
A process-based fire parameterization of intermediate complexity has been
developed for global simulations in the framework of a Dynamic Global Vegetation Model (DGVM) in an Earth System Model (ESM). Burned area in a
grid cell is estimated by the product of fire counts and average burned area
of a fire. The scheme comprises three parts: fire occurrence, fire
spread, and fire impact. In the fire occurrence part, fire counts rather
than fire occurrence probability are calculated in order to capture the
observed high burned area fraction in areas of high fire frequency and
realize parameter calibration based on MODIS fire counts product. In the
fire spread part, post-fire region of a fire is assumed to be elliptical in
shape. Mathematical properties of ellipses and some mathematical derivations
are applied to improve the equation and assumptions of an existing fire
spread parameterization. In the fire impact part, trace gas and aerosol
emissions due to biomass burning are estimated, which offers an interface
with atmospheric chemistry and aerosol models in ESMs. In addition, flexible
time-step length makes the new fire parameterization easily applied to
various DGVMs.
Global performance of the new fire parameterization is assessed by using an
improved version of the Community Land Model version 3 with the Dynamic Global Vegetation Model (CLM-DGVM). Simulations are compared against the
latest satellite-based Global Fire Emission Database version 3 (GFED3) for
1997–2004. Results show that simulated global totals and spatial patterns
of burned area and fire carbon emissions, regional totals and spreads of
burned area, global annual burned area fractions for various vegetation
types, and interannual variability of burned area are reasonable, and closer
to GFED3 than CLM-DGVM simulations with the commonly used Glob-FIRM fire
parameterization and the old fire module of CLM-DGVM. Furthermore, average
error of simulated trace gas and aerosol emissions due to biomass burning is
7% relative to GFED3. Results suggest that the new fire parameterization
may improve the global performance of ESMs and help to quantify
fire-vegetation-climate interactions on a global scale and from an Earth
system perspective. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|