Michael Notaro U.W. Madison Center for Climatic Research

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Michael Notaro
U.W. Madison
Center for Climatic Research
[email protected]
- Study the impact of rising levels of equivalent
carbon dioxide on global vegetation and climate
- Evaluate FOAM-LPJ model
- Focus on higher latitudes
- Compare findings with satellite data and tree
ring data
- Later continue study to predict future changes
in vegetation and climate
DATASETS
- Global Potential Vegetation (Ramankutty and Foley, 1999)
- Global Continuous Fields of Vegetation Cover for 1992-1993
(DeFries et al., 1999; 2000)
- Pathfinder V3 AVHRR FPAR (1981-2001) (Myneni et al., 1997)
- HYDE Global Historical Land Cover for 1900 and 1990 (Goldewijk,
2001; Goldewijk and Battjes, 1997)
- International Tree-Ring Data Bank’s Tree Ring Width (212 sites)
(1800-1999) (45ºN-75ºN) (<500m) (standardized)
- NCEP-NCAR Reanalysis (Kalnay et al., 1996)
- NASA GISS Land-Ocean Surface Air Temperature Anomalies (19001999) (Hansen et al., 1999; Reynolds and Smith, 1994; Smith et al.,1996)
- Climatic Research Unit’s CRUTEM2 Monthly Land Air Temperature
Anomalies (1851-2003) (Jones and Moberg, 2003)
- NOAA Extended Reconstruction SST (ERSST) (1900-1999) (Smith
and Reynolds, 2003)
- Xie-Arkin CPC Merged Analysis of Precipitation (1979-2001) (Xie and
Arkin, 1996; 1997)
- CRU TS2.0 Land Surface Precipitation (1901-2000)
- Willmott-Matsuura V1.01 Temperature and Precipitation (1950-1996)
(Willmott and Matsuura, 2000)
Fraction of Photosynthetically Active Radiation
MEAN
TREND
April-October 1982-2000 FPAR Anomalies
FOAM = Fast Ocean Atmosphere Model
(Jacob, 1997) - R15 (PCCM3+OM3)
LPJ = Lund-Potsdam-Jena dynamic
vegetation model (Sitch, 2000) 1.4°x2.8°
FOAM-LPJ = fully coupled global
atmosphere-ocean-land model with
dynamic vegetation
Percent difference (Model-Obs) in Annual Average
Land Precipitation (Obs = Xie Arkin 1979-2001)
W
D
W
W
W
D
Contours: 20, 50, 100, and 300%
W
JAN
O
B
S
M
O
D
E
L
January and July FPAR
JUL
Model
Obs
1900
1990
FC
Diff
Comparison of Simulated and Satellite-Based % Tree Cover
1950-1996 Surface Air T Change (Willmott-Matsuura)
A
N
N
U
A
L
D
J
F
Change in Simulated Surface Air T
Shading:
<0.10
Change in Simulated Surface Air T (DJF)
Shading:
<0.10
Trend in Simulated Precipitation
RP
P
R
Global
Annual T
DJF T
(Land
38-60N,
120W-140E
Global
Annual
SST
Global
Tree
Cover
40-75N
Boreal
Summerg
Tree Cover
MJJAS
FPAR
TREE COVER
VEGETATION COVER
R ( 0 .7 %)
R ( 1 .0 %)
P (1 .9 %)
P (1 .7 %)
RP (2 .3 %)
RP (2 .9 %)
RP
R
P
Trend
In %
Forest
Cover
Change in FPAR
RP
P
R
AVHRR
AVHRR
Remote
Percent Change in Evapotranspiration (Run P)
Decomposition of Simulated FPAR
FPAR 
9
9
9
9
i1
i1
i1
i1
 f i di   f i di   f idi   f idi
Mean FPAR Change in
with no trend leaf cover
or length
of growing
season
(GDD)
Change in
fractional
vegetation
cover
Interactions
or feedbacks
between f
and d (small)
For the 9 pft’s,
f = vegetation cover fraction
d = seasonal leaf cover fraction
Trend
fd 
f d
f d 
Trend
fd 
f d
f d 
Trend
fd 
f d
f d 
DECIDUOUS
EVERGREEN
Tree
Ring
Width
Apr-Oct T
Ring Width
RP
P
R
CONCLUSIONS
- FOAM-LPJ captures the major global biomes but
overproduces tree cover due to FOAM’s wet bias and
LPJ’s woody bias.
- Both satellite data and FOAM-LPJ reveal a global
greening trend and poleward expansion of the
northern boreal forest
- The radiative forcing is responsible for most of the
warming trend, although the physiological forcing
contributes some additional local warming.
- While the physiological forcing dominates the global
greening trend, both forcings play a role in the boreal
expansion.