Data from: Systematic assessment of retrieval methods for canopy far-red solar-induced chlorophyll fluorescence (SIF) using automated high-frequency field spectroscopy
No Access Until
Permanent Link(s)
Collections
Other Titles
Abstract
Data in support of the following research: Remote sensing of solar-induced chlorophyll fluorescence (SIF) offers potential to infer photosynthesis across scales and biomes. Many retrieval methods have been developed to estimate top-of-canopy SIF using ground-based spectroscopy. However, inconsistencies among methods may confound interpretation of SIF dynamics, eco-physiological/environmental drivers, and its relationship with photosynthesis. Using high temporal- and spectral-resolution ground-based spectroscopy, we aimed to 1) evaluate performance of SIF retrieval methods under diverse sky conditions using continuous field measurements; 2) assess method sensitivity to fluctuating light, reflectance and fluorescence emission spectra; and 3) inform users for optimal ground-based SIF retrieval. Analysis included field measurements from bi-hemispherical and hemispherical-conical systems and synthetic upwelling radiance constructed from measured downwelling radiance, simulated reflectance and simulated fluorescence for benchmarking. Fraunhofer-based differential optical absorption spectroscopy (DOAS) and singular vector decomposition (SVD) retrievals exhibit convergent SIF-PAR relationships and diurnal consistency across different sky conditions while O2A-based spectral fitting method (SFM), SVD, and modified Fraunhofer line discrimination (3FLD) exhibit divergent SIF-PAR relationships across sky conditions. Such behavior holds across system configurations, though hemispherical-conical systems diverge less across sky conditions. O2A retrieval accuracy, influenced by atmospheric distortion, improves with a narrower fitting window and when training SVD with temporally-local spectra. This may impact SIF-photosynthesis relationships interpreted by previous studies using O2A-based retrievals with standard (759-767.76 nm) fitting windows. Fraunhofer-based retrievals resist atmospheric impacts but are noisier and more sensitive to assumed SIF spectral shape than O2A-based retrievals. We recommend SVD or SFM using reduced fitting window (759.5-761.5 nm) for robust far-red SIF retrievals across sky conditions.
Journal / Series
Volume & Issue
Description
Sponsorship
Date Issued
Publisher
Keywords
Location
Effective Date
Expiration Date
Sector
Employer
Union
Union Local
NAICS
Number of Workers
Committee Chair
Committee Co-Chair
Committee Member
Degree Discipline
Degree Name
Degree Level
Related Version
Related DOI
Related To
Related Part
Based on Related Item
Has Other Format(s)
Part of Related Item
Related To
Related Publication(s)
Christine Yao-Yun Chang. (2020). SunCornell/SIF_retrieval_methods: SIF_retrieval_methods (Version v1.0). [code] Zenodo. https://doi.org/10.5281/zenodo.3759965