(A–F) Seasonal hourly averages of (A) far-red SIF; (B) GPP; (C) far-red SIF yield (SIF/APAR); (D) LUE (GPP/APAR); (E) relative far-red SIF (SIF/reflected radiance in the NIR retrieval window); and (F) APAR. Summer data are from June 21, 2017 to August 30, 2017 and from June 1, 2018 to June 29, 2018. Fall data are from September 1, 2017 to November 15, 2017. Winter data are from November 15, 2017 to March 31, 2018. Spring data are from April 1, 2018 to May 23, 2018. Shaded regions represent 1 SE of the hourly mean. Green, summer; gold, fall; blue, winter; and purple, spring.