Michael NotaroU.W. Madison

Center for Climatic Researchmnotaro@wisc.edu

OCT

2004

- Later continue study to predict future changes in vegetation and climate

- 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

DATASETSDATASETS- 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 (1900- 1999) (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)

Contours: 20, 50, 100, and 300%

W

W

WW

W

D

D

January and July FPARJAN JUL

OBS

MODEL

Model Obs

1900 1990

FC Diff

Comparison of Simulated and Satellite-Based % Tree Cover

1950-1996 Surface Air T Change (Willmott-Matsuura)

ANNUAL

DJF

Change in Simulated Surface Air T

Shading: <0.10

Change in Simulated Surface Air T (DJF)

Shading: <0.10

Trend in Simulated PrecipitationRP

P

R

GlobalAnnual T

DJF T (Land

38-60N, 120W-140E

Global Annual

SST

GlobalTree

Cover

40-75N Boreal

SummergTree Cover

MJJASFPAR

TREE COVER VEGETATION COVER

R (0.7%)

P (1.9%)

RP (2.3%)

R (1.0%)

P (1.7%)

RP (2.9%)

TrendIn %

ForestCover

RP

R

P

Change in FPAR

RP

AVHRR

R

P

AVHRRRemote

Percent Change in Evapotranspiration (Run P)

€

FPAR = f i di + f i ′ d i

i=1

9

∑ + ′ f i

i=1

9

∑i=1

9

∑ di + ′ f i

i=1

9

∑ ′ d i

Decomposition of Simulated FPAR

For the 9 pft’s,

f = vegetation cover fraction

d = seasonal leaf cover fraction

Mean FPARwith no trend

Change in leaf cover or lengthof growing season(GDD)

Change infractionalvegetationcover

Interactionsor feedbacksbetween f and d (small)

€

f ′ d

€

′ f d

€

′ f ′ d

Trend

€

f ′ d

€

′ f d

€

′ f ′ d

Trend

€

f ′ d

€

′ f d

€

′ f ′ d

Trend

DECIDUOUS EVERGREEN

TreeRing

Width

Apr-Oct T

Ring Width

RP

P R

CONCLUSIONS

- 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.

- FOAM-LPJ captures the major global biomes but overproduces tree cover due to FOAM’s wet bias and LPJ’s woody bias.