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| Titel |
Deforestation fire carbon emissions for the last millennium simulated with the global vegetation model JSBACH |
| VerfasserIn |
Jessica Engels, Silvia Kloster, Stiig Wilkenskjeld |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250076120
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| Zusammenfassung |
| Humankind has fundamentally modified the Earth’s terrestrial surface to secure food and
other resources by conversion of natural ecosystems to managed areas. Until today,
these anthropogenic changes in land cover have resulted in an extent of conversion
from natural land cover by human activities to managed areas between one-third
and one-half of the total Earth’s land cover (Vitousek (1997)). Large parts of this
conversion take place in the form of deforestation fires, which release atmospheric
trace gases and aerosols into the atmosphere. These deforestation fires are climate
dependent and follow a strong seasonal cycle, which is important for atmospheric
chemistry.
In the present study, the offline version of the JSBACH carbon pool model of the Max
Planck Institute for Meteorology (MPI-M) is used to simulate climate dependent
deforestation fire carbon emissions over the last millennium (800-2010). For this, the
standard carbon allocation scheme is extended by four additional anthropogenic carbon
pools. These pools separate the carbon amount released due to anthropogenic land cover
change from the carbon amount released due to natural processes to the atmosphere. The
climate dependent deforestation fire emissions are simulated in the model by a linear
dependency on the soil moisture. This new carbon allocation scheme results in land cover
change carbon emissions, which accumulate between 800 and 2010 to 239.8 PgC.
Thereby, the climate dependent deforestation fire carbon emissions accumulate over the
last millennium to 182.6 PgC yr-1 in the year 2010, which accounts for 76% of
the total land cover change carbon emissions. Compared to present day satellite
based observational data sets (GFED3) the simulated mean deforestation fire carbon
emissions (1422.5 TgC yr-1) averaged over the time period 1997-2009 are about a
factor of 4 higher than the observed carbon emissions (386.4 TgC yr-1) on a global
scale. However, compared to a field-observational based estimate, the simulations
underestimate deforestation fire carbon emissions by around 54% for the time period
1990-2007.
Generally, the simulations performed for the present study capture the observed
peak fire months of deforestation fire carbon emissions. However, the length of the
burning season is slightly overestimated, and the range between the maximum and
minimum deforestation fire carbon emissions within a year is underestimated in the
model.
This study provides a consistent modelling estimate of monthly mean deforestation fire
emissions for the last millennium that resolve the seasonal dependent nature of the
deforestation process, which can be applied in atmospheric chemistry modelling studies. |
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