Monitoring of long-range transported air pollutants in Annual Report 2019 Wenche Aas, Sabine Eckhardt, Markus Fiebig, Sverre Solberg and Karl Espen Yttri

NILU report 4/2020

NILU report 4/2020 ISBN: 978-82-425-3000-4 CLASSIFICATION: ISSN: 2464-3327 Norwegian Environment Agency A – Unclassified (open report) M-1710 | 2020

DATE SIGNATURE OF RESPONSIBLE PERSON NUMBER OF PAGES

09.08.2020 Ole-Anders Braathen, 133 Deputy Director (sign.)

TITLE PROJECT LEADER

Monitoring of long-range transported air pollutants in Norway Wenche Aas Annual Report 2019 NILU PROJECT NO.

O-113007/O-113008 AUTHOR(S) QUALITY CONTROLLER Wenche Aas, Sabine Eckhardt, Markus Fiebig, Sverre Solberg and Karl Espen Yttri Kjetil Tørseth

REPORT PREPARED FOR CONTRACT REF.

Norwegian Environment Agency Contract number 17078061 Postboks 5672 Sluppen, 7485 Trondheim

ABSTRACT

This report presents results from the monitoring of atmospheric composition and deposition of air pollution in 2019, and focuses on main components in air and precipitation, particulate and gaseous phase of inorganic constituents, particulate carbonaceous matter, ground level ozone and particulate matter. In 2019, it was an unusual wide-spread episode during April causing high concentrations of most pollutants at several sites.

NORWEGIAN TITLE

Overvåking av langtransportert forurenset luft og nedbør. Atmosfæriske tilførsler 2019.

KEYWORDS

Atmosphere and climate/ Aerosols and particles/ Ground level ozone/ Acid rain and eutrophication/ Atmosfære og klima/ Aerosoler og partikler Bakkenært ozon Sur nedbør og overgjødsling

ABSTRACT (in Norwegian)

Denne rapporten omhandler resultater fra overvåkningsprogrammet for langtransportert forurenset luft og nedbør og atmosfæriske tilførsler i 2019. Rapporten presenterer målinger av uorganiske hovedkomponentene i luft og nedbør, partikulært karbonholdig materiale, partikkelmasse og bakkenært ozon. I 2019 ble det observert en uvanlig omfattende episode med høye konsentrasjoner av luftforurensing på flere stasjoner.

PUBLICATION TYPE: Digital document (pdf) COVER PICTURE: Source: NILU, Observatory

© NILU – Norwegian Institute for Air Research

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NILU report 4/2020

Contents

Sammendrag ...... 4 Summary ...... 6 1 The monitoring programme 2019 ...... 8 2 The weather in Norway 2019 ...... 11 3 Inorganic components ...... 13 3.1 Observations in 2019 ...... 13 3.1.1 Chemical composition in precipitation ...... 13 3.1.2 Chemical composition in air ...... 17 3.1.3 Total deposition of sulfur and nitrogen ...... 21 3.2 Trends ...... 23 3.3 Summary ...... 30 4 EC and OC ...... 31 4.1 Introduction ...... 31 4.2 Concentrations of OC in PM10, PM2.5 and PM10-2.5 ...... 31 4.3 Concentrations of EC in PM10 and PM2.5 ...... 32 4.4 Relative contribution of EC and OC to PM ...... 33 4.5 Trends for concentrations of EC and OC ...... 33 4.6 Concentrations of levoglucosan, mannosan and galactosan in PM10 ...... 34 4.7 Summary ...... 35 5 Particulate matter, mass concentrations ...... 36 5.1 Introduction ...... 36 5.2 PM10, PM2.5 and PM10-2.5 concentrations ...... 36 5.3 Trends ...... 39 5.4 Compliance with EU limit values and Air-Quality Guidelines for PM10 and PM2.5 ...... 41 5.5 Chemical composition of particulate matter ...... 42 5.6 Particle number concentrations ...... 45 5.7 Summary ...... 45 6 Ground-level ozone ...... 46 6.1 Monitoring network ...... 46 6.2 Ground-level ozone in Norway ...... 47 6.3 Norwegian ozone levels in 2019 ...... 48 6.4 Exceedances of the limit values for protection of human health ...... 51 6.5 Exceedance of the threshold values for protection of vegetation ...... 54 6.6 Long-term trends in ground level ozone...... 57 6.7 Summary ...... 62 7 The April 2019 episode ......