Chapter 4: Present day ozone distribution and trends relevant to human Health Zoe Fleming U. Leicester, Ruth Doherty U. Edinburgh UK Cooper, O. R., Xu, X., Feng, Z., Simpson, D., Schultz, M., Pinto, J., Shallcross, D., Moolla, R., Lefer, B., Solberg, S., von Schneidemesser, E., Jaffe, D., Hamad, S. Colette, A.

Chapter Structure Introduction Acute exposure and Air quality standards Plethora of metrics- differ by timescale and world region Station data selection and classification Networks utilised for health metric calculations and time periods Optimal station classification for health purposes- i.e. accounting for population Regional aggregation Health metrics for present-day ozone Which one/ones/few…? Present-day ozone and metrics relevant for human health Present-day distribution and disparities in distributions Population –weighting Ozone trends and metrics relevant for human health Time –series and trend methodology Encompassing trends for different metrics/distributions/percentiles Mapping Regional ozone trends Discussion

Major Science points/issues: Optimal station classification for health  Urban standard classification, suburban/rural and baseline or…. Joly et al. 2011

 Urban standard classification, suburban/rural and baseline or….  In addition: Urban (high NO x emissions) Urban (zero ozone at night in winter- if available) Urban (population density) Urban (lighting) Major Science points/issues: Optimal station classification for health

Major Science points/issues: Regional aggregation  Regional aggregation for present-day ozone and for trends Averaging, kriging …. How complex? Which regions?- common decision for TOAR chapters Disparity in distributions? European EMEP ozone monitoring sites, the number of years of data during 1990–2009 (courtesy S. Solberg) TF-HTAP source regions

Major Science points/issues: Which metrics?  Wide range including:  4 th highest 8 hour average for each year (USA)  Ditto daytime average  Maximum daily 8 hour  Maximum daily 1 hour  SUMO35, SUM010  W90  Percentiles annual and seasonal  Number of exceedances above an absolute threshold (8 and 1 hr)  Running mean 3 month average

Major Science points/issues: Which metrics? (cntd)

Major Science points/issues: Population –weighting Qualitative vs. qualitative Grid-cell for population vs. Stations are sites Population as link to global health dominated by urban areas Population weighted ozone by region (from population map, GPW Colombia web site)

Major Science points/issues: trends for different metrics/distributions/percentiles Percentiles on x –axis Different percentiles show different trends Sensitivity of individual trends to ozone metrics – percentile values of ozone as given on the x-axis. (Simpson et al. 2014)

Major Science points/issues: displaying regional trends globally Cooper et al. 2015

Data periods  Chapter 3…

Overlap  Chapter 3resent-day  Xioabin Chinese data (Beijing Bureau of Environmental Protection) has been running an air quality monitoring network consisting of 35 sites since 2013  Trends use 1994 to 2013 or 2004 to 2013?

Overlap