Solar Induced Fluorescence as an Application Ready Early Warning Indicator of Flash Drought

Flash drought has garnered major attention due to its devastating impact on both agricultural and ecological systems impacting production and income for producers, due to its rapid onset nature, and poor predictability. Solar induced fluorescence (SIF) is an increasingly well-known and reliable indicator of vegetation health which captures rapid changes in how plants absorb and use light under stress. Recent efforts leveraging machine learning (ML) trained on spaceborne SIF and vegetation data from other sensors are producing seamless maps of SIF at spatial resolutions (~5 km) aligned with land management needs. Three recent studies, Mohammadi et al. (2022, https://doi.org/10.1073/pnas.2202767119), Parazoo et al. (2024, https://doi.org/10.1029/2024GL108310), and Behera et al. (2025, https://doi.org/10.1029/2024GL113419), directly show the value of SIF as an early indicator of flash drought. The growing literature connecting SIF to vegetation stress across a range of ecosystems highlights the immediate value of SIF to facilitate agricultural, rangeland, and forestry management. Through advanced studies and calibration, we contend that SIF-based data products are ready to move from research to operations. To utilize high resolution (5 km) and low-latency (1 week – 2 months) SIF mapping for regional- to global- scale drought monitoring, there are several current efforts to prepare SIF data for immediate use by the drought monitoring community including the U.S. Drought Monitor.