Figure 2
From: Sun-induced fluorescence and gross primary productivity during a heat wave
Midday (10–14 local time) mean (±standard deviation) (a) inferred gross primary productivity (GPP, µmol m−2 s−1), (b) the ecosystem relative uptake rate (ERU) and the normalised difference vegetation index (NDVI from hyperspectral sensor), and sun-induced fluorescence in the (c) O2-A (F760) and (d) O2-B (F687) band (W m−2 sr−1 µm−1) during the heat wave and the first day thereafter. Hourly air temperature (Tair, °C), vapour pressure deficit (VPD, kPa) and incident photosynthetically active radiation (PAR, µmol m−2 s−1) are shown in panels a-d as grey shading. Simulated SIF is scaled to the measured value during the first day of the heat wave (see Methods). Simulated GPP and SIF (green symbols) are slightly offset horizontally from measured values (black symbols) for improved clarity.
