TY  - JOUR
AU  - Lu, Wendi
AU  - Zeng, Yelu
AU  - Vilfan, Nastassia
AU  - Huang, Jianxi
AU  - Van Wittenberghe, Shari
AU  - He, Yachang
AU  - Gao, Yongyuan
AU  - Junker-Frohn, Laura
AU  - Johnson, Jennifer E.
AU  - Su, Wei
AU  - Liu, Qinhuo
AU  - Siegmann, Bastian
AU  - Hao, Dalei
TI  - Characterizing leaf-scale fluorescence with spectral invariants
JO  - Remote sensing of environment
VL  - 322
SN  - 0034-4257
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2025-02037
SP  - 114704
PY  - 2025
AB  - Sun-induced chlorophyll fluorescence (SIF) is increasingly recognized as a non-destructive probe for tracking terrestrial photosynthesis. Emerging developments in spectral invariants theory provide an innovative and efficient approach for representing SIF radiative transfer processes at the canopy scale. However, modeling leaf-scale fluorescence based on the spectral invariants properties (SIP) remains underexplored. In this study, the spectral invariants theory is employed for the first time to model the leaf-scale total, backward and forward fluorescence (leaf-SIP SIF). The leaf-SIP SIF model separates the leaf-scale radiative transfer process into two distinct components: the wavelength-dependent one associated with leaf biochemical properties, and the wavelength-independent component linked to leaf structural characteristics. The leaf structure-related effects are characterized by two spectrally invariant parameters: the photon recollision probability (p) and the scattering asymmetry parameter (q), which are parameterized using the directly measurable leaf dry matter. Evaluation against field measurements shows that the proposed leaf-SIP SIF model has a good performance, with coefficient of determination (R2) of 0.89, 0.89, 0.90 and root mean squared errors (RMSE) of 1.28, 0.69, 0.74 Wm−2μm−1sr−1, respectively for the total, backward, and forward fluorescence (660–800 nm). The leaf-SIP SIF model with a more concise formulation demonstrates comparable performance with the widely used Fluspect model. The leaf-SIP SIF model provides a simple and efficient approach for simulating leaf-scale fluorescence, with the potential to be integrated into a unified SIP-based model framework for simulating the radiative transfer processes across the soil-leaf-canopy-atmosphere continuum.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001448467100001
DO  - DOI:10.1016/j.rse.2025.114704
UR  - https://juser.fz-juelich.de/record/1040884
ER  -