land cover ccicci.esa.int/sites/default/files/content/docs/bon... · • notable difference in...
TRANSCRIPT
CCI Phase 1 results Climate research perspectives
Land Cover CCI
Multi-level validation strategy
CCI-LC products 3 LC state products for the 2000, 2005 and 2010 epochs
Fate of anthropogenic CO2 emissions (2003-2012 average)
Land component of Earth System Model Simulates the Energy, Water and Carbon balance
Dynamic global vegetation model
Land cover map
LSCE – ORCHIDEE model
• Surface description: a tile approach • A mosaïc of vegetation
• 10 to 15 different PFTs
MOHC – Joint UK Land Environment Simulator (JULES)
• JULES uses a tiled model of sub-grid heterogeneity • 9 Land surface types: BL tree, NL tree, C3 grass, C4
grass, Shrub, Urban, Water, Ice, Bare Soil
MPI-M – JSBACH model
• MPI-Earth Surface Model (ESM), with JSBACH as land surface component which can be run independently (offline simulations)
• 13 different PFTs
Earth system models comparison
Modeling Team
Offline Online
Original LC LC_CCI LC Dynamic vegeta9on
Original LC LC_CCI LC
LSCE-‐ORCHIDEE
V V V V V
MOHC-‐JULES V V V V V
MPI-‐JSBACH V V ✗ V V
-‐ Same climate forcing for offline simulaAons (WATCH WFDEI) -‐ Same Epoch (2010) for LC_CCI inputs – but modeling groups define climate zones… -‐ Treatment of land use fluxes and disturbance up to the modeling teams
1. Does the use of CCI-LC maps improve model-data comparisons? 2. Does the use of CCI-LC maps reduce model-model differences? 3. Does consistency in land cover improve model comparisons?
LC-CCI to improve initial model conditions
Current land cover map • Outdated land cover inputs
• IGBP land cover (Belward et al. 1999) and,
• Olson vegetaAon map with 96 classes (1983)
Land cover Köppen-Geiger
climate zones
Phenology & Physiognomy
Plant Functional Types Land
Cover -‐>
PFT
Conversion
Too
l (BEA
M)
ESA LC_CCI PFT datasets
PFT comparison - Bare fraction
Possibly too high in high latitudes due to 85% allocation from sparse vegetation categories
ORCHIDEE
JULES JSBACH
PFT comparison - C3 / crops fractions
Decrease in high latitudes due to replacement by bare soil/barren
ORCHIDEE (natural C3 fraction)
JULES (All C3)
JSBACH (crops)
PFT comparison - BoBS fraction
Fractional difference (-)
ORCHIDEE Notable increase in E Europe at expense of evergreens
By-model experiment Carbon, energy and water budget
• LAI
• Gross Primary Production
(GPP)
• Net Primary Production (NPP)
• Radiation & moisture fluxes
• Heat sensible flux
• Latent sensible flux
• Surface temperature
Evapotranspiration
• Heterotrophic respiration
• Albedo
• Runoff
• Total precipitation changes
• Validation of Dynamic Global
Vegetation Model (in
comparison with IGBP map)
LAI comparison
Red: higher LAI with Olson-derived simulations
Blue: higher LAI with CCI_LC-derived simulations
ORCHIDEE: LAI comparison between Olson and CCI-LC Mean difference in LAI (Olson – CCI_LC)
• Comparison to GIMMS3gSurface parameters
• AVHRR GIMMS3g LAI dataset (Zhu et al. 2013 Remote Sensing)
• RMSE and bias between simulations of LAI and GIMMS3g
data with Olson and CCI-LC derived PFT maps
LAI comparison
0
0.5
1
1.5
2
Olson CCI
RM
SE
Bia
s
0
0.2
0.4
0.6
0.8
Olson CCI
ORCHIDEE: LAI comparison between Olson and CCI-LC
Carbon budget - GPP
0
25
50
75
100
125
1980 1985 1990 1995 2000 2005Year
GtC
yr−1
SourceHadGEM2A: ControlHadGEM2A: LC_CCI 2000HadGEM2A: LC_CCI 2005HadGEM2A: LC_CCI 2010MODIS GPP MOD17A3Jung et al
Global Mean Annual GPP
Offline Control LC_CCI 2010
GPP (Gt C yr-1) 152.5 166.7
Estimates of global annual GPP: • 123 ± 8 Gt C yr-1 (Beer et al.
2010) • 119.4 ± 5.9 Gt C yr-1 (Jung
et al. 2011) • 120 Pg C yr−1 (Denman et
al. 2007) • 109.29 Pg C yr−1 (Zhao et
al. 2005) for 2001-2003 period
• Discrepancy between offline and online GPP likely due to variations in JULES
JULES: Increase in global GPP in both online and offline simulations
Carbon budget - GPP
Gross Primary Production ( gC m−2 yr−1 )LC_CCI 2010 − Control
50°S
0°
50°N
100°W 0° 100°E
−2000 −1500 −1000 −500 0 500 1000 1500 2000
JULES: Spatial distribution of differences
Carbon budget - GPP Gross Primary Production ( gC m−2 yr−1 )
Model − Observations
50°S
0°
50°N
Control
100°W 0° 100°E
LC_CC:2010
−3000 −2000 −1000 0 1000 2000 3000
• LC_CCI 2010 shows reduction in biases in:
• West Africa • Southern Africa • Amazon • India • South East Asia
JULES: Comparison to estimates from Jung et al. (2011)
KgC/m2/yr
Carbon budget - NPP
• Large increase in NPP over croplands • Decrease in high latitudes due to decrease in grass cover
ORCHIDEE: NPP comparison (CCI-LC – Olson)
LMDz transport: comparison to GlobalView data ! improvement of the CO2 seasonal cycle with
reduced amplitude
Carbon budget - Evaluation using atm. CO2 concentration
ORCHIDEE
Bare C3 C4
0.000.050.100.150.20
−3−2−1
0
0255075
100
−10−5
05
10
0.000.040.08
−200
2040
−75−50−25
0
−2024
−4−2
024
−1.0−0.5
0.00.51.0
GPP
cVegET
SMAlb
SHLH
Tmax90pct
Pr90pctlr20m
m
J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N DMonth
valu
e
PFT, %increase (point ID)Bare, 50% (9)C3, 63% (13)C4, 32% (21)C4, 39% (8)C4, 45% (14)C4, 66% (10)C4, 71% (11)
TropicalBare C3 C4
0.000.050.100.150.20
−3−2−1
0
0255075
100
−10−5
05
10
0.000.040.08
−200
2040
−75−50−25
0
−2024
−4−2
024
−1.0−0.5
0.00.51.0
GPP
cVegET
SMAlb
SHLH
Tmax90pct
Pr90pctlr20m
m
J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N DMonth
valu
e
PFT, %increase (point ID)Bare, 50% (9)C3, 63% (13)C4, 32% (21)C4, 39% (8)C4, 45% (14)C4, 66% (10)C4, 71% (11)
Tropical11
10
Shrub Urban Water Bare Ice
-0.10 0.00 -0.04 -0.08 0.00
0.03 0.00 0.00 -0.12 0.00
ID BL NL C3 C4
10 -0.28 0.00 -0.17 0.66 11 -0.21 0.00 -0.40 0.71
C4 grass BL Tree C3 grass • Leads to: • Increase in GPP • Reduction in veg. C • Increase in extreme
max temp in Sept (10)
• Extreme precipitation earlier in season (11)
Bare C3 C4
0.000.050.100.150.20
−3−2−1
0
0255075
100
−10−5
05
10
0.000.040.08
−200
2040
−75−50−25
0
−2024
−4−2
024
−1.0−0.5
0.00.51.0
GPP
cVegET
SMAlb
SHLH
Tmax90pct
Pr90pctlr20m
m
J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N DMonth
valu
e
PFT, %increase (point ID)Bare, 50% (9)C3, 63% (13)C4, 32% (21)C4, 39% (8)C4, 45% (14)C4, 66% (10)C4, 71% (11)
TropicalRadiation & moisture fluxes
JULES: West Africa Increase in C4 Grass, replacing BL tree or C3 grass in old maps
Radiation & moisture fluxes
Maximum temperature JULES
Energy budget - Visible albedo
Cha
nge
in a
lbed
o (-
)
ORCHIDEE (CCI-LC – Olson)
• Increase in high lat. albedo with increased bare soil • Decrease in W Canada with increasing tree cover • Decrease in some cropland areas
By catchment experiment Surface albedo
• Over high- and mid-latitude catchments: CCI-LC albedo higher than reference • Over arid and semi-arid regions: improvement with CCI-LC albedo
JSBACH
By catchment experiment WFDEI 2m temperature
• Effect of albedo difference visible in estimated 2m t° (↑ albedo " ↓t°)
• General improvement over most catchments
JSBACH
By catchment experiment Uncertainty due to epoch
• Notable difference in CCI-LC maps only in Amazon and Congo (large-scale deforestation " increased albedo) ! need for simulation with LC change
• For other regions, using the 2010 epoch is a reasonable assumption
JSBACH
Models inter-comparison Albedo
• Stronger sensitivity of JSBACH than JULES to CCI-LC maps
• Overestimation over the Northern Asia region (w.r.t. GlobaAlbedo)
• Over Amazon and West African, JSBACH closer to GlobAlbedo but farther away from MODIS
• Significant improvement of ORCHIDEE with CCI-LC maps
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
AMZ WAF SAF NAS SAS NAU
Surface Albedo
MODIS
GlobAlbedo
WFDEI-‐REF
WFDEI-‐CCI
ECHAM6-‐REF
ECHAM6-‐CCI
JULES-‐REF
JULES-‐CCI
HadGEM2A-‐REF
HadGEM2A-‐CCI
0
0.05
0.1
0.15
0.2
0.25
0.3
AMZ WAF SAF NAS SAS NAU
Surface Albedo
MODIS
GlobAlbedo
ORCHIDEE-‐Olson
ORCHIDEE-‐CCI
ORCHIDEEonl-‐Olson
ORCHIDEEonl-‐CCI
ORCHIDEE-‐DGVM
Over Giorgi regions AMZ = Amazonia WAF = West Africa SAF = South Africa NAS = North Asia SAS = South Asia NAU = North Australia
Models inter-comparison Evapotranspiration
• Direction of change when using CCI-LC data:
• Is consistent between offline & online simulation for JULES and JSBACH
• Opposite direction for ORCHIDEE over AMZ, WAF and SAS
• Improvement over high latitude for 3 models
Over Giorgi regions AMZ = Amazonia WAF = West Africa SAF = South Africa NAS = North Asia SAS = South Asia NAU = North Australia
-‐60.0%
-‐40.0%
-‐20.0%
0.0%
20.0%
40.0%
60.0%
AMZ WAF SAF NAS SAS NAU
Deviation from LandFlux Diag ET mean
LF MinLF MaxWFDEI-‐REFWFDEI-‐CCIECHAM6-‐REFECHAM6-‐CCIJULES-‐REFJULES-‐CCIHadGEM2A-‐REFHadGEM2A-‐CCI
-‐80.0%
-‐60.0%
-‐40.0%
-‐20.0%
0.0%
20.0%
40.0%
60.0%
AMZ WAF SAF NAS SAS NAU
Deviation from LandFlux Diag ET mean
LF Min
LF Max
ORCHIDEE-‐Olson
ORCHIDEE-‐CCI
ORCHIDEEonl-‐Olson
ORCHIDEEonl-‐CCI
ORCHIDEEoff-‐DGVM
Summary
• Significant differences are observed in the land surface description when using CCI-LC maps w.r.t. older reference maps
• Boreal region with the continuum bare – sparse vegetation – grassland – JULES & ORCHIDEE: vegetation to bare soil è increased albedo associated with
decrease in extreme temperatures
– JSBACH: more forest & less bare soil è increases of LAI, biomass and surface albedo è decrease of surface temperature and sensible heat flux
• JSBAC model: less forest and more bare soil in West Africa, Sahel, Congo
– LAI and biomass decrease, albedo increase – reduced NPP, GPP and evapotranspiration – soil moisture and runoff increases.
• Globally, large reduction in C3 grass cover and increase in C4 grass cover ! generally increases GPP, but decreases cVeg, associated with improvements in max temp bias
Summary
• All models show high sensitivity to land cover as an initial condition for both stocks and fluxes
• Mainly changes in high latitudes and tropics • Improvement in high latitude NPP, in GPP online • Improvement in terrestrial carbon sink estimate and seasonality • For Amazon and Congo, albedo is increasing from the earliest 2000 Epoch to the
latest 2010 Epoch ! indication of large-scale deforestation of tropical rainforest • Mixed response of biomass, depending on region BUT global reduction in positive
bias • Improvement to atmospheric data at high latitudes • Improved representation of 2m air temperature and surface albedo in some regions
• CCI-LC constrains the problem of where to improve existing model processes and parameters
• Implementation of fully consistent changes of land cover (not only input data but all associated parameters – e.g. PFTs distributions) would lead to a more larger impact of CCI data
2 papers to come
Paper 1 - “Land cover uncertainty in land carbon cycle processes”
… Making sense of multiple benchmarks … Paper 2 - “A plant functional type classification for Earth System Models from the European Space Agency Essential Climate Variables Program”
… Toward regular PFT classification from ESA-CCI …
For the future
• Further discussion/development of cross-walking procedure (LCCS class into PFTs)
• In Phase 1: assess the impact of LC uncertainty with all models with their own reference map
Next step: Same experiment with all models with the same reference map • Model optimization for new CCI-LC maps • More links between C and water/energy expertise in modelling
groups • Create a LC change scenario (yearly) and assess its impact on the
C, water and energy fluxes (especially on on-going deforestation and associated fluxes)
• Use of WB product and/or LC condition products in models