TY  - JOUR
AU  - Lefohn, Allen S.
AU  - Malley, Christopher S.
AU  - Smith, Luther
AU  - Wells, Benjamin
AU  - Hazucha, Milan
AU  - Simon, Heather
AU  - Naik, Vaishali
AU  - Mills, Gina
AU  - Schultz, Martin
AU  - Paoletti, Elena
AU  - De Marco, Alessandra
AU  - Xu, Xiaobin
AU  - Zhang, Li
AU  - Wang, Tao
AU  - Neufeld, Howard S.
AU  - Musselman, Robert C.
AU  - Tarasick, David
AU  - Brauer, Michael
AU  - Feng, Zhaozhong
AU  - Tang, Haoye
AU  - Kobayashi, Kazuhiko
AU  - Sicard, Pierre
AU  - Solberg, Sverre
AU  - Gerosa, Giacomo
TI  - Tropospheric ozone assessment report: Global ozone metrics for climate change, human health, and crop/ecosystem research
JO  - Elementa
VL  - 6
SN  - 2325-1026
CY  - Washington, DC
PB  - BioOne
M1  - FZJ-2018-02810
SP  - 28
PY  - 2018
AB  - Assessment of spatial and temporal variation in the impacts of ozone on human health, vegetation, and climate requires appropriate metrics. A key component of the Tropospheric Ozone Assessment Report (TOAR) is the consistent calculation of these metrics at thousands of monitoring sites globally. Investigating temporal trends in these metrics required that the same statistical methods be applied across these ozone monitoring sites. The nonparametric Mann-Kendall test (for significant trends) and the Theil-Sen estimator (for estimating the magnitude of trend) were selected to provide robust methods across all sites. This paper provides the scientific underpinnings necessary to better understand the implications of and rationale for selecting a specific TOAR metric for assessing spatial and temporal variation in ozone for a particular impact. The rationale and underlying research evidence that influence the derivation of specific metrics are given. The form of 25 metrics (4 for model-measurement comparison, 5 for characterization of ozone in the free troposphere, 11 for human health impacts, and 5 for vegetation impacts) are described. Finally, this study categorizes health and vegetation exposure metrics based on the extent to which they are determined only by the highest hourly ozone levels, or by a wider range of values. The magnitude of the metrics is influenced by both the distribution of hourly average ozone concentrations at a site location, and the extent to which a particular metric is determined by relatively low, moderate, and high hourly ozone levels. Hence, for the same ozone time series, changes in the distribution of ozone concentrations can result in different changes in the magnitude and direction of trends for different metrics. Thus, dissimilar conclusions about the effect of changes in the drivers of ozone variability (e.g., precursor emissions) on health and vegetation exposure can result from the selection of different metrics.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000429374000001
C6  - pmid:30345319
DO  - DOI:10.1525/elementa.279
UR  - https://juser.fz-juelich.de/record/845585
ER  -