18 April 2018

Future Heat Waves and Surface Ozone Events

Science

Understand how more intense heat waves in the future could affect severe surface ozone events.

Analyze a global Earth system model that simulates the observed relationship between heat waves and elevated surface ozone levels with associated severe health impacts

--The model is driven by emissions of greenhouse gases and ozone precursors from a medium-high emission scenario (RCP6.0) compared to an experiment with ozone precursor emissions fixed at 2005 levels 

Impact

Ozone concentrations during future more intense heat waves decrease in areas where ozone precursors are prescribed to decrease in RCP6.0 (e.g. most of North America and Europe), and ozone concentrations during heat waves increase in areas where ozone precursors either increase or have little change (e.g. central Asia, the Mideast, northern Africa). With stabilized ozone precursors, surface ozone concentrations increase during future heat waves compared to non-heat wave days in most regions except where there is ozone suppression that is likely associated with changes in isoprene emissions at high temperatures from forests.

Summary

Ozone concentrations during future more intense heat waves decrease in areas where ozone precursors are prescribed to decrease in RCP6.0 (e.g. most of North America and Europe), and ozone concentrations during heat waves increase in areas where ozone precursors either increase or have little change (e.g. central Asia, the Mideast, northern Africa). With stabilized ozone precursors, surface ozone concentrations increase during future heat waves compared to non-heat wave days in most regions except where there is ozone suppression that is likely associated with changes in isoprene emissions at high temperatures from forests.

Contact
Gerald Meehl
National Center for Atmospheric Research (NCAR)
Publications
Meehl, G, C Tebaldi, S Tilmes, J Lamarque, S Bates, A Pendergrass, and D Lombardozzi.  2018.  "Future Heat Waves and Surface Ozone Events."  Environmental Research Letters, doi:10.1088/1748-9326/aabcdc.