Ozone deposition impact assessments for forest canopies require accurate ozone flux partitioning on diurnal timescales

作者：A.J. Visser, L. Ganzeveld, Ignacio Goded, Maarten Krol, Ivan Mammarella, Giovanni Manca, K. F. Boersma · 发表于：Atmospheric chemistry and physics · 年份：2021 · DOI：10.5194/acp-21-18393-2021 · 被引用次数：25 · 研究领域：Plant responses to elevated CO2、Atmospheric chemistry and aerosols、Atmospheric Ozone and Climate

Abstract. Dry deposition is an important sink of tropospheric ozone that affects surface concentrations and impacts crop yields, the land carbon sink, and the terrestrial water cycle. Dry deposition pathways include plant uptake via stomata and non-stomatal removal by soils, leaf surfaces, and chemical reactions. Observational studies indicate that ozone deposition exhibits substantial temporal variability that is not reproduced by atmospheric chemistry models due to a simplified representation of vegetation uptake processes in these models. In this study, we explore the importance of stomatal and non-stomatal uptake processes in driving ozone dry deposition variability on diurnal to seasonal timescales. Specifically, we compare two land surface ozone uptake parameterizations – a commonly applied big leaf parameterization (W89; Wesely, 1989) and a multi-layer model (MLC-CHEM) constrained with observations – to multi-year ozone flux observations at two European measurement sites (Ispra, Italy, and Hyytiälä, Finland). We find that W89 cannot reproduce the diurnal cycle in ozone deposition due to a misrepresentation of stomatal and non-stomatal sinks at our two study sites, while MLC-CHEM accurately reproduces the different sink pathways. Evaluation of non-stomatal uptake further corroborates the previously found important roles of wet leaf uptake in the morning under humid conditions and soil uptake during warm conditions. The misrepresentation of stomatal versus non-stomatal u...