457
Remote Sensing and Modeling of Global Evapotranspiration
19.5 VALIDATIONS AT FLUX TOWER SITES
19.5.1 flux toweRS
The AmeriFlux network (http://public.ornl.gov/ameriflux/) was established in 1996
as a network of field sites that provide continuous observations of ecosystem level
exchange of CO 2 , water, and energy. AmeriFlux, part of the global FLUXNET network, is currently composed of 106 sites in North America, Central America, and
South America. FLUXNET, an international network measuring terrestrial carbon,
water, and energy fluxes at multiple time scales, coordinates regional and global
analyses of observations from eddy covariance tower sites. Until March 1, 2010,
more than 500 tower sites (Figure 19.4) are operating on a long-term and continuous
(b)
Networks
AmeriFlux
AsiaFlux
CARBOAFRICA
CarboEurope IP
Carbomont
ChinaFLUX
Canadian CP
Other
KoFlux
LBA
OzFlux
Sardinilla Proj
TROPI-DRY
USCCC
Unaffiliated
FLUXNET
October 2010, 524 Sites
700
600
500
400
300
200
100
0
1995
2000
2005
Year
Number of towers
2010
Growth of FLUXNET
502 towers as of March 1, 2010
Africa (25)
Asia (84)
Australia/Oceania (17)
Europe (152)
North America (194)
South America (30)
(a)
FIGURE 19.4 (a) Distribution of FLUXNET tower sites. (b) Growth rate of FLUXNET,
1992–2010. (From http://www.fluxnet.ornl.gov/fluxnet.)
Remote Sensing and Modeling of Global Evapotranspiration
19.5 VALIDATIONS AT FLUX TOWER SITES
19.5.1 flux toweRS
The AmeriFlux network (http://public.ornl.gov/ameriflux/) was established in 1996
as a network of field sites that provide continuous observations of ecosystem level
exchange of CO 2 , water, and energy. AmeriFlux, part of the global FLUXNET network, is currently composed of 106 sites in North America, Central America, and
South America. FLUXNET, an international network measuring terrestrial carbon,
water, and energy fluxes at multiple time scales, coordinates regional and global
analyses of observations from eddy covariance tower sites. Until March 1, 2010,
more than 500 tower sites (Figure 19.4) are operating on a long-term and continuous
(b)
Networks
AmeriFlux
AsiaFlux
CARBOAFRICA
CarboEurope IP
Carbomont
ChinaFLUX
Canadian CP
Other
KoFlux
LBA
OzFlux
Sardinilla Proj
TROPI-DRY
USCCC
Unaffiliated
FLUXNET
October 2010, 524 Sites
700
600
500
400
300
200
100
0
1995
2000
2005
Year
Number of towers
2010
Growth of FLUXNET
502 towers as of March 1, 2010
Africa (25)
Asia (84)
Australia/Oceania (17)
Europe (152)
North America (194)
South America (30)
(a)
FIGURE 19.4 (a) Distribution of FLUXNET tower sites. (b) Growth rate of FLUXNET,
1992–2010. (From http://www.fluxnet.ornl.gov/fluxnet.)