Assessment of surface O₃-induced risk variations on wheat using different exposure data in Hebei, China

Accurate assessment of the yield and economic consequences of wheat cultivation heavily depends on the estimation of O₃ exposure. In this study, we used the cumulative O₃ concentration over 40 ppb h (AOT40) and the mean daytime 7 h O₃ concentration (M7) as exposure evaluation indicators to evaluate the changes of wheat production loss (WPL) and economic loss (ECL) in Hebei, China, based on four different O₃ data sources. The results showed AOT40- and M7-related WPLs increased from 3.0 and 0.3 million metric tons to 8.6 and 0.9 million metric tons, respectively, due to O₃ exposure during winter wheat growing seasons from 2015 to 2019. The AOT40 (M7)-related ECLs increased from 680.3 to 2401.0 million USD (41.1-213.2 million USD). The estimated mean changes in O₃-related WPLs and ECLs were both approximately 30 % different among different exposure data. Based on AOT40 and M7, the predicted hour concentration data of the observation-fused CMAQ results data (FSD) simulation had the minimum increase (AOT40). Cangzhou, Baoding, and Handan experienced more serious WPL/ECL losses based on FSD data in 2018. The interaction between heat stress and O₃ pollution further exacerbates wheat yield losses. Our findings will enhance our understanding of the consequences of increased surface O₃ concentration on wheat and suggest potential measures to mitigate these negative effects.