Abstract Solar‐induced chlorophyll fluorescence (SIF) retrieved from spaceborne measurements is widely used as an indicator of vegetation activity. However, this weak emission can be confused with the inelastic scattering component of sunlight that lacks distinctive Fraunhofer lines. Through high‐fidelity radiative transfer simulations of nadir‐mode observations near the O2 ${\mathrm{O}}_{2}$ A‐band, we show that this signal can cause artificially high SIF estimates–reaching up to 0.35 mW/nm/sr/m2 ${\mathrm{m}\mathrm{W}/\mathrm{n}\mathrm{m}/\mathrm{s}\mathrm{r}/\mathrm{m}}^{2}$ over vegetation‐free regions like the Sahara, Greenland, and Antarctica. Current “zero‐level offset” corrections, originally intended to address instrument errors, partially remove these erroneous signals but leave significant residual biases (± $\pm $0.15 mW/nm/sr/m2 ${\mathrm{m}\mathrm{W}/\mathrm{n}\mathrm{m}/\mathrm{s}\mathrm{r}/\mathrm{m}}^{2}$) that correlate with surface brightness, elevation, and viewing geometry. We introduce a lookup table approach based on physical simulations to directly estimate and subtract inelastic scattering, which substantially improves SIF retrieval accuracy. Correcting the inelastic scattering effect refines the interpretation of global SIF applications–ranging from agricultural monitoring to assessments of ecosystem health and the carbon cycle.
Observations from the Little Bunker
Last updated: August 18, 2025 06:15 PM
Atmospheric CO₂
425.4 ppm
+18.4
ppm/year
Atmospheric CH₄
1934.91 ppb
+9.11
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year