First observations of global and seasonal terrestrial chlorophyll fluorescence from space

Abstract

Remote sensing of terrestrial vegetation fluorescence from space is of interest because it can potentially provide global coverage of the functional status of vegetation. For example, fluorescence observations may provide a means to detect vegetation stress before chlorophyll reductions take place. Although there have been many measurements of fluorescence from ground- and airborne-based instruments, there has been scant information available from satellites. In this work, we use high-spectral resolution data from the Thermal And Near-infrared Sensor for carbon Observation – Fourier Transform Spectrometer (TANSO-FTS) on the Japanese Greenhouse gases Observing SATellite (GOSAT) that is in a sun-synchronous orbit with an equator crossing time near 13:00 LT. We use filling-in of the potassium (K) I solar Fraunhofer line near 770 nm to derive chlorophyll fluorescence and related parameters such as the fluorescence quantum yield at that wavelength. We map these parameters globally for two months (July and December 2009) and show a full seasonal cycle for several different locations, including two in the Amazonia region. We also compare the derived fluorescence information with that provided by the MODIS Enhanced Vegetation Index (EVI). These comparisons show that for several areas these two indices exhibit different seasonality and/or relative intensity variations, and that changes in fluorescence frequently lead those seen in the EVI for those regions. The derived fluorescence therefore provides information that is related to, but independent of the reflectance

Disentangling Changes in the Spectral Shape of Chlorophyll Fluorescence: Implications for Remote Sensing of Photosynthesis

“…Recent advances in the remote sensing of solar‐induced ChlF (SIF)—indicative of the product of Φ F t,λ and absorbed photosynthetically active radiation (APAR)—show promise for mapping plant photosynthetic dynamics globally (Frankenberg et al, ; Guanter et al, ; Joiner et al, ; Sun et al, , ). However, the direct connection between PAM ChlF, remotely sensed SIF, and photosynthesis is lacking.…”

Estimation of Leaf Photosynthetic Capacity From Leaf Chlorophyll Content and Leaf Age in a Subtropical Evergreen Coniferous Plantation

“…Photosynthesis is a key component of process‐based terrestrial biosphere models (TBMs) (Dietze & Moorcroft, ) and accounts for 90% of water and carbon fluxes between the atmosphere and the biosphere (Joiner et al, ; Zhu et al, ). TBMs represent the most sophisticated and accurate means of predicting ecosystem carbon fluxes and usually include the Farquhar–von Caemmerer–Berry model (FvCB) kinetic enzyme model to simulate photosynthetic rates (Farquhar et al, ).…”

Varying Contributions of Drivers to the Relationship Between Canopy Photosynthesis and Far‐Red Sun‐Induced Fluorescence for Two Maize Sites at Different Temporal Scales

“…This red and far‐red light emission, also known as chlorophyll fluorescence, has long been a powerful tool to study photosynthesis at the leaf level (Baker, ). Recently, the sun‐induced chlorophyll fluorescence (SIF) signals became remotely detectable with the development of hyperspectral technologies (Frankenberg et al, ; Grossmann et al, ; Joiner et al, , ; Köhler et al, ; Rascher et al, ; Sun et al, ; X. Yang, Shi, et al, ; Zareo‐Tejada et al, ), which has been rapidly expanding the potential of chlorophyll fluorescence to estimate photosynthetic rates from short‐term leaf scale to larger spatial and temporal scales.…”