Variations in ozone exposure in the landscape with consideration of topography and coastal climate

Klingberg, J. (1), Karlsson, P. E. (2), Pihl Karlsson, G. (2), Hu, Y. (3), Chen, D. (3) , Pleijel, H. (1)

(1) Department of Plant and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-40530 Gothenburg, Sweden(2) IVL Swedish Environmental Research Institute, P.O. Box 5302, SE-40014 Gothenburg, Sweden(3) Department of Earth Sciences, University of Gothenburg, P.O. Box 460, SE 405 30 Gothenburg, Sweden

An activity of the CLEO Programme, funded by the Swedish Environmental Protection Agency. Measurements were funded by the County Administration Board of Västra Götaland.

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• Surface ozone concentrations, [O3], depended on the position in the landscape and vary on small geographical scales.

• Variations in [O3] were related to the distance from the coast and for inland sites to the relative topography within a 3 km radius.

• Relative topography was more relevant than altitude in explaining the diurnal dynamics of [O3] for inland sites.

• Diurnal [O3] range correlated with diurnal air temperature range across all sites.

• Diurnal air temperature range correlated with daily air pressure

• Climate change may alter surface [O3] through changes in vertical air mixing, independently of changes in emissions, chemistry, deposition or long-range transport

Highlights

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Methodology

x

xx

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x

xLanna

Hedared

Sandhult

Nidingen

Råö

Alafors

xÖstad

x BrobackaxRönnäng

3 km

red cross; mobile systemblack cross; permanent monitoring sites

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• Three days with anticyclonic weather conditions.

• Only 8 km distance between Östad and Brobacka.

Hourly ozone concentrations depend on the position in the landscape

Östad

Råö

Brobacka

40 km

Site type Relative topo-graphy, m

Altitude, m a.s.l.

Östad Inland valley -23 63

Brobacka Inland hilltop 46 167

Råö Coastal - -

Östad RåöBrobacka

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Ozo

ne

pp

b

12 Sept -06 13 Sept -06 14 Sept -06

↑

↓ ↓↓

↑↑

↑ sunrise

↓ sunset

555

Diurnal ozone concentrations depend on distance to the coast and relative topography

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Time of day

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Östad

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Time of day

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Nidingen

Östad

c

Östad

Sandhult

Hedared

40 km

Nidingen

Site type Relative topo-graphy, m

Altitude, m a.s.l.

Östad Inland valley -23 63

Hedared Inland valley -11 191

Sandhult Inland hilltop 38 296

Nidingen Coastal - -

Hedared vs Östad Sandhult vs Östad

Nidingen vs Östad

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Diurnal ozone range correlated with relative topography

The diurnal ozone concentra-tion range (DOR) of a certain inland site, relative to Östad (=1.0), could be significantly correlated to the relative topography of the specific site.

y = -0.007x + 0.87

R2 = 0.87p = 0.015

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-30 -20 -10 0 10 20 30 40 50

Relative altitude (m)

Site

/Öst

ad D

OR

(pp

b)

b

Relative topography (m)low high

777Diurnal ozone range correlated with diurnal temperature range

y = 1.36x + 10.2

R2 = 0.39p = 0.001

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DTR (°C)

DO

R (

ppb)

Lanna

Hedared

Brobacka

Sandhult

Rönnäng

Nidingen

The diurnal ozone concentration range (DOR) could be significantly correlated with the diurnal air temperature range (DTR) across all investigated locations.

Blue; coastalRed; inland hilltopGreen; inland valley

888Diurnal temperature range correlated with daily air pressure

The diurnal air temperature range (DTR) could be significantly correlated with daily air pressure for sites separated into different categories.

y = 0.07x - 69

R2 = 0.10p = 0.077

y = 0.18x - 177

R2 = 0.31p = 0.010

y = 0.38x - 369

R2 = 0.46p = 0.005

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985 995 1005 1015 1025 1035

Daily average air pressure (hPa)

DT

R (

°C)

Lanna

Hedared

Brobacka

Sandhult

Rönnäng

Nidingen

Blue; coastalRed; inland hilltopGreen; inland valley