TY - JOUR
T1 - On the relationship between sub-daily instantaneous and daily total gross primary production
T2 - Implications for interpreting satellite-based SIF retrievals
AU - Zhang, Yao-Jun
AU - Xiao, Xiangming
AU - Zhang, Yongguang
AU - Wolf, Sebastian
AU - Zhou, Sha
AU - Joiner, Joanna
AU - Guanter, Luis
AU - Verma, Manish
AU - Sun, Ying
AU - Yang, Xi
AU - Paul-Limoges, Eugénie
AU - Gough, Christopher M.
AU - Wohlfahrt, Georg
AU - Gioli, Beniamino
AU - van der Tol, Christiaan
AU - Yann, Nouvellon
AU - Lund, Magnus
AU - de Grandcourt, Agnès
PY - 2018/2/1
Y1 - 2018/2/1
N2 - Spatially and temporally continuous estimation of plant photosynthetic carbon fixation (or gross primary production, GPP) is crucial to our understanding of the global carbon cycle and the impact of climate change. Besides spatial, seasonal and interannual variations, GPP also exhibits strong diurnal variations. Satellite retrieved solar-induced chlorophyll fluorescence (SIF) provides a spatially continuous, but temporally discrete measurement of plant photosynthesis, and has the potential to be used to estimate GPP at global scale. However, it remains unclear whether the seasonal time series of SIF snapshots taken at a fixed time of the day can be used to infer daily total GPP variation at spatial and seasonal scales. In this study, we first used GPP estimates from 135 eddy covariance flux sites, covering a wide range of geographic locations and biome types, to investigate the relationship between the instantaneous GPP (GPPinst) and daily GPP (GPPdaily) on the seasonal course for different times of the day. Latitudinal and diurnal patterns were found to correspond to variations in photosynthetically active radiation (PAR) and light use efficiency (LUE), respectively. We then used the Soil-Canopy Observation Photosynthesis and Energy Balance (SCOPE) model and the FluxCom GPP product to investigate the instantaneous and daily SIF-GPP relationships at five flux tower sites along a latitudinal gradient and at a global scale for different biome types. The results showed that daily SIF had a stronger linear correlation with daily GPP than instantaneous SIF at the seasonal scale, with an instantaneous to daily SIF conversion factor following the latitudinal and seasonal pattern driven by PAR. Our study highlights the necessity to take the latitudinal and diurnal factors into consideration for SIF-GPP relationship analyses or for physiological phenology analyses based on SIF.
AB - Spatially and temporally continuous estimation of plant photosynthetic carbon fixation (or gross primary production, GPP) is crucial to our understanding of the global carbon cycle and the impact of climate change. Besides spatial, seasonal and interannual variations, GPP also exhibits strong diurnal variations. Satellite retrieved solar-induced chlorophyll fluorescence (SIF) provides a spatially continuous, but temporally discrete measurement of plant photosynthesis, and has the potential to be used to estimate GPP at global scale. However, it remains unclear whether the seasonal time series of SIF snapshots taken at a fixed time of the day can be used to infer daily total GPP variation at spatial and seasonal scales. In this study, we first used GPP estimates from 135 eddy covariance flux sites, covering a wide range of geographic locations and biome types, to investigate the relationship between the instantaneous GPP (GPPinst) and daily GPP (GPPdaily) on the seasonal course for different times of the day. Latitudinal and diurnal patterns were found to correspond to variations in photosynthetically active radiation (PAR) and light use efficiency (LUE), respectively. We then used the Soil-Canopy Observation Photosynthesis and Energy Balance (SCOPE) model and the FluxCom GPP product to investigate the instantaneous and daily SIF-GPP relationships at five flux tower sites along a latitudinal gradient and at a global scale for different biome types. The results showed that daily SIF had a stronger linear correlation with daily GPP than instantaneous SIF at the seasonal scale, with an instantaneous to daily SIF conversion factor following the latitudinal and seasonal pattern driven by PAR. Our study highlights the necessity to take the latitudinal and diurnal factors into consideration for SIF-GPP relationship analyses or for physiological phenology analyses based on SIF.
KW - Correction factor
KW - Diurnal variation
KW - FluxCom
KW - FLUXNET
KW - Light use efficiency
KW - Phenology
KW - Photosynthetically active radiation
KW - SCOPE
KW - ITC-ISI-JOURNAL-ARTICLE
KW - 2023 OA procedure
U2 - 10.1016/j.rse.2017.12.009
DO - 10.1016/j.rse.2017.12.009
M3 - Article
AN - SCOPUS:85037523988
SN - 0034-4257
VL - 205
SP - 276
EP - 289
JO - Remote sensing of environment
JF - Remote sensing of environment
ER -