The influence of model spatial resolution on simulated ozone and fine particulate matter for Europe: implications for health impact assessments
We examine the impact of model horizontal resolution on simulated concentrations of surface ozone (O3) and particulate matter less than 2.5 µm in diameter (PM2.5), and the associated health impacts over Europe, using the HadGEM3–UKCA chemistry–climate model to simulate pollutant concentrations at a...
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Published in | Atmospheric chemistry and physics Vol. 18; no. 8; pp. 5765 - 5784 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Katlenburg-Lindau
Copernicus GmbH
25.04.2018
Copernicus Publications |
Subjects | |
Online Access | Get full text |
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Summary: | We examine the impact of model horizontal resolution on simulated
concentrations of surface ozone (O3) and particulate matter less than
2.5 µm in diameter (PM2.5), and the associated health impacts
over Europe, using the HadGEM3–UKCA chemistry–climate model to simulate
pollutant concentrations at a coarse (∼ 140 km) and a finer
(∼ 50 km) resolution. The attributable fraction (AF) of total
mortality due to long-term exposure to warm season daily maximum 8 h running
mean (MDA8) O3 and annual-average PM2.5 concentrations is then
calculated for each European country using pollutant concentrations simulated
at each resolution. Our results highlight a seasonal variation in simulated
O3 and PM2.5 differences between the two model resolutions in
Europe. Compared to the finer resolution results, simulated European O3
concentrations at the coarse resolution are higher on average in winter and
spring (∼ 10 and ∼ 6 %, respectively). In contrast, simulated
O3 concentrations at the coarse resolution are lower in summer and
autumn (∼ −1 and ∼ −4 %, respectively). These differences
may be partly explained by differences in nitrogen dioxide (NO2)
concentrations simulated at the two resolutions. Compared to O3, we find
the opposite seasonality in simulated PM2.5 differences between the two
resolutions. In winter and spring, simulated PM2.5 concentrations are
lower at the coarse compared to the finer resolution (∼ −8 and
∼ −6 %, respectively) but higher in summer and autumn (∼ 29
and ∼ 8 %, respectively). Simulated PM2.5 values are also
mostly related to differences in convective rainfall between the two
resolutions for all seasons. These differences between the two resolutions
exhibit clear spatial patterns for both pollutants that vary by season, and
exert a strong influence on country to country variations in estimated AF for
the two resolutions. Warm season MDA8 O3 levels are higher in most of
southern Europe, but lower in areas of northern and eastern Europe when
simulated at the coarse resolution compared to the finer resolution.
Annual-average PM2.5 concentrations are higher across most of northern
and eastern Europe but lower over parts of southwest Europe at the coarse
compared to the finer resolution. Across Europe, differences in the AF
associated with long-term exposure to population-weighted MDA8 O3 range
between −0.9 and +2.6 % (largest positive differences in southern
Europe), while differences in the AF associated with long-term exposure to
population-weighted annual mean PM2.5 range from −4.7 to +2.8 %
(largest positive differences in eastern Europe) of the total mortality.
Therefore this study, with its unique focus on Europe, demonstrates that
health impact assessments calculated using modelled pollutant concentrations,
are sensitive to a change in model resolution by up to ∼ ±5 %
of the total mortality across Europe. |
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ISSN: | 1680-7324 1680-7316 1680-7324 |
DOI: | 10.5194/acp-18-5765-2018 |