From the Ground to Space: Using Solar-Induced Chlorophyll Fluorescence to Estimate Crop Productivity
Abstract
Timely and accurate monitoring of crops is essential for food security. Here, we examine how well solar‐induced chlorophyll fluorescence (SIF) can inform crop productivity across the United States. Based on tower‐level observations and process‐based modeling, we find highly linear gross primary production (GPP):SIF relationships for C4 crops, while C3 crops show some saturation of GPP at high light when SIF continues to increase. C4 crops yield higher GPP:SIF ratios (30–50%) primarily because SIF is most sensitive to the light reactions (does not account for photorespiration). Scaling to the satellite, we compare SIF from the TROPOspheric Monitoring Instrument (TROPOMI) against tower‐derived GPP and county‐level crop statistics. Temporally, TROPOMI SIF strongly agrees with GPP observations upscaled across a corn and soybean dominated cropland (R² = 0.89). Spatially, county‐level TROPOMI SIF correlates with crop productivity (R² = 0.72; 0.86 when accounting for planted area and C3/C4 contributions), highlighting the potential of SIF for reliable crop monitoring.
Additional Information
© 2020 American Geophysical Union. Received 10 FEB 2020; Accepted 4 MAR 2020; Accepted article online 9 MAR 2020. Part of this research was funded by the NASA Carbon Cycle Science program (grant NNX17AE14G). L.H. thanks the Resnick Sustainability Institute at Caltech for fellowship support. TROPOMI SIF data generation by P.K. and C.F. is funded by the Earth Science U.S. Participating Investigator program (grant NNX15AH95G). TROPOMI SIF product is available at ftp://fluo.gps.caltech.edu/data/tropomi/. County‐level crop statistics is available at the USDA NASS Quick Stats Database (quickstats.nass.usda.gov). Crop‐specific land cover data layer CDL can be accessed at https://nassgeodata.gmu.edu/CropScape/.Attached Files
Published - 2020GL087474.pdf
Supplemental Material - grl60362-sup-0001-2020gl087474-si.docx
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Additional details
- Eprint ID
- 102399
- Resolver ID
- CaltechAUTHORS:20200408-093014100
- NASA
- NNX17AE14G
- Resnick Sustainability Institute
- NASA
- NNX15AH95G
- Created
-
2020-04-08Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Resnick Sustainability Institute, Division of Geological and Planetary Sciences