Modelling dynamic vegetation within the Earth System models Victor - - PowerPoint PPT Presentation
Modelling dynamic vegetation within the Earth System models Victor Brovkin Max-Planck-Institut f r Meteorologie KlimaCampus, Hamburg NEESPI Workshop, CITES Conference, Krasnoyarsk, 15 July 2009 Climate system Ocean Land surface after John
NEESPI Workshop, CITES Conference, Krasnoyarsk, 15 July 2009
after John Osborn, NOAA
Land surface Ocean
Sellers et al., Science, 1997
Interactions between the land surface and the atmosphere that have direct impacts on the physical climate system.
(A) Surface radiation budget. (B) Effect of heat fluxes on the atmosphere.
after Foley et al. (2003)
Biogeochemical effects
Changes in ecosystems affect sources and sinks of:
Biogeophysical effects
Changes in ecosystems affect:
magnitude)
Purves et al., Life: The Science of biology
– classifications by Köppen, Holdridge – plant functional type (PFT) concept: species are lumped into several PFTs, such as evergreen needleleaf trees (BIOME1) – Biogeography + carbon cycle models (BIOME4)
– Fractional land cover representation (plant functional type) – Temporal dynamics – Disturbances as driving forcing of vegetation succession (explicitly or implicitly)
Cramer et al., Glob. Change Biol., 2001
Cramer et al., Glob. Change Biol., 2001
Atmosphere horizontal dynamics Atmosphere vertical dynamics MPIOM Ocean
vertical structure land surface processes
vertical atmosphere column
Dynamic land biosphere Stomata Model: BETHY
Phenology model: (LoGro-P)
Soil model: ECHAM5-scheme:
Soil scheme Carbon Flow Model: Cbalance
Dynamic land cover:
Albedo model:
FPC1 FPC2 FPCi
Land area excluded from vegetation dynamics (e.g. crops & pastures, glaciers)
FPCn
Fast variable: Bare soil, Bs Slow variable: Desert or bare ground, Bg
Tiling of land surface
ECHAM land grid cell
damaged i burnt i i i i
FPC FPC FPC MORT FPC EST dt dFPC − − − = ) ( ) (
Bare soil fraction is diagnostic:
ODE for FPC (fractional projected cover) solved daily:
) ( 1
+ − =
woodyPFT i grassPFT i s
FPC FPC B
damaged i burnt i i i i
FPC FPC FPC MORT FPC EST dt dFPC − − − = ) ( ) (
∑
⋅ =
woodyPFT k k i i rel i
FPC NPP FPC NPP NPP
α α
) ( ) (
i i
PFT rel i
NPP FPC EST τ = ) (
mort PFT i i
i
FPC FPC MORT τ = ) ( < − + ≥ =
crit crit crit b i crit i burn PFT
q q if q q q k q q if
i
), 1 ( ,
max max
τ τ τ
burn PFT i burnt i
i
FPC FPC τ = )) ) 1 ( 1 , (max(
* 5 . 20
∑
−
− − =
allPFT LAI i yr g
i
e FPC ave B
Desert fraction: FPC fraction burnt: q – rel. air humidity
FPC dynamical equation solved daily: Mortality: Establishment: Relative NPP advantage:
, i i i i i i i a i i
potential equilibrium in absence
actual „mixed“ equilibrium induced by disturbances 1 FPC(PFT1) – dominant PFT FPC(PFT2) 1
Carbon dynamics is done by JSBACH carbon cycle module FPC dynamics is simulated by dynamic veget module
SPITFIRE model (Thonicke et al., submitted)
Fraction burnt (yr-1)
Coupled model ECHAM5-MPIOM- JSBACH
Observed, MODIS data (Hansen et al., 2006) Interactive ECHAM5-MPIOM- JSBACH
Brovkin et al., GRL, 2009
Observed, MODIS data (Hansen et al., 2006) Interactive ECHAM5-MPIOM- JSBACH
Temperature, precipitation Albedo, transpiration, runoff, surface roughness
Global annual mean temperature,°C
fixed vegetation interactive vegetation
forest grass
Brovkin et al., GRL, 2009
°C
Winter (DJF) Summer (JJA) FOREST world GRASSLAND world
Brovkin et al., GRL, 2009
Jones et al., Nature Geoscience, 2009
Projected changes in boreal forest cover in the Hadley Centre model
potential dynamic
– Increased representativeness of species, modelling on the patches level (e.g. LPJ-GUESS) – Flexible reclassification of PFTs for paleo-applications – Direct modelling of climate-relevant plant traits (albedo) response to climate change without PFT step
– Accounting for formation of vegetation patterns – Rainfall intermittency in drylands – Disturbances regimes
The main objective of the Action is a cross-disciplinary assessment of our current understanding of the terrestrial biosphere from an Earth system perspective to improve the reliability of future Earth system projections in coupled climate-biosphere simulations Bringing together biospheric modellers, ecologists, and data gathering community 4 working groups:
Chair of Action MC: Christian Reick, MPI for Meteorology (Hamburg) Action duriation: June 2009 – June 2013 Participants: 14 COST countries; 4 non-COST countries & institutions Russian participants invited: Leonid Golubyatnikov (IAP), Dmitry Luri (IG) Open Symposium: 9-11 February 2010, Hamburg www.terrabites.net (not yet available!)