@article{fdi:010090699,
  title = {{N}et fluxes of broadband shortwave and photosynthetically active radiation complement {NDVI} and near infrared reflectance of vegetation to explain gross photosynthesis variability across ecosystems and climate},
  author = {{M}allick, {K}. and {V}erfaillie, {J}. and {W}ang, {T}. {X}. and {O}rtiz, {A}. {A}. and {S}zutu, {D}. and {Y}i, {K}. and {K}ang, {Y}. {H}. and {S}hortt, {R}. and {H}u, {T}. and {S}ulis, {M}. and {S}zantoi, {Z}. and {B}oulet, {G}illes and {F}isher, {J}. {B}. and {B}aldocchi, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A} significant challenge in global change research is understanding how vegetation interacts with the environment to influence ecosystem gross primary productivity ({GPP}) through carbon assimilation. {O}ne emerging objective is to consistently predict {GPP} fluctuations worldwide by establishing a robust scaling relationship between {GPP} measured at flux towers and satellite spectral reflectance data. {H}owever, a major hurdle in achieving this goal is the discrepancy in spatial resolution between early satellite measurements and eddy flux measurements. {B}y using a large set of growing season data covering 100 site -years in {N}orth and {C}entral {A}merica, we explored the potential of transforming incident and reflected shortwave ({R}g) and photosynthetically active radiation ({PAR}) measurements into a broadband normalized difference vegetation index ({NDVI}) and nearinfrared ({NIR}) reflectance of vegetation ({NIR}v) which simultaneously explains the {GPP} variability. {W}e found that the broadband {NDVI} and {NIR}v derived from {R}g and {PAR} measurements at the daily time scale were highly correlated with {P}lanet {F}usion, {L}andsat-8/9, and {S}entinel -2 narrowband {NDVI} and {NIR}v across a wide range of climate and ecological gradients. {T}he differences between satellite and broadband {NDVI} and {NIR}v were found to be significantly associated with soil background variations, phenological stages, water stress and signal saturation of broadband {NIR} reflectance at high biomass. {T}he seasonal variability of broadband {NDVI} and {NIR}v remarkably captured the seasonality of vegetation phenology, evaporative fraction, {GPP} and rainfall in different ecosystems. {A}lthough saturation of {GPP} at high {NDVI} was evident, a linear relationship between broadband {NIR}v times incident {PAR} versus {GPP} indicated the effectiveness of {NIR}v-based approach to capture the hidden light use efficiency impacts on {GPP}. {O}ur study concludes that inexpensive measurement of {R}g and {PAR} components can provide reliable information on {NDVI}, {NIR}v, and {GPP} uninterruptedly. {T}his enhances the sensing capability of flux tower sites without requiring additional spectrometer measurements. {T}he proposed in -situ vegetation indices make a compelling case on using radiation signals for handshaking between ecosystem -scale measurements and remote sensing observables relevant to carbon uptake.},
  keywords = {{S}pectral reflectance ; {B}roadband vegetation index ; {NIR}v ; {G}ross primary productivity ; {P}hotosynthetically active radiation ; {E}cosystem ; {C}limate ; {AMERIQUE} {DU} {NORD} ; {AMERIQUE} {CENTRALE} ; {MONDE}},
  booktitle = {},
  journal = {{R}emote {S}ensing of {E}nvironment},
  volume = {307},
  numero = {},
  pages = {114123 [28 ]},
  ISSN = {0034-4257},
  year = {2024},
  DOI = {10.1016/j.rse.2024.114123},
  URL = {https://www.documentation.ird.fr/hor/fdi:010090699},
}