Trends of inorganic and organic aerosols and precursor gases in Europe: Insights from the EURODELTA multi-model experiment over the 1990-2010 period
Journal article, 2019

In the framework of the EURODELTA-Trends (EDT) modeling experiment, several chemical transport models (CTMs) were applied for the 1990-2010 period to investigate air quality changes in Europe as well as the capability of the models to reproduce observed long-term air quality trends. Five CTMs have provided modeled air quality data for 21 continuous years in Europe using emission scenarios prepared by the International Institute for Applied Systems Analysis/Greenhouse Gas - Air Pollution Interactions and Synergies (IIASA/GAINS) and corresponding year-by-year meteorology derived from ERA-Interim global reanalysis. For this study, long-term observations of particle sulfate (SO2 4-), total nitrate (TNO3), total ammonium (TNHx) as well as sulfur dioxide (SO2) and nitrogen dioxide (NO2) for multiple sites in Europe were used to evaluate the model results. The trend analysis was performed for the full 21 years (referred to as PT) but also for two 11-year subperiods: 1990-2000 (referred to as P1) and 2000-2010 (referred to as P2). The experiment revealed that the models were able to reproduce the faster decline in observed SO2 concentrations during the first decade, i.e., 1990-2000, with a 64%-76% mean relative reduction in SO2 concentrations indicated by the EDT experiment (range of all the models) versus an 82% mean relative reduction in observed concentrations. During the second decade (P2), the models estimated a mean relative reduction in SO2 concentrations of about 34%-54%, which was also in line with that observed (47%). Comparisons of observed and modeled NO2 trends revealed a mean relative decrease of 25% and between 19% and 23% (range of all the models) during the P1 period, and 12% and between 22% and 26% (range of all the models) during the P2 period, respectively. Comparisons of observed and modeled trends in SO4 2- concentrations during the P1 period indicated that the models were able to reproduce the observed trends at most of the sites, with a 42%-54% mean relative reduction indicated by the EDT experiment (range of all models) versus a 57% mean relative reduction in observed concentrations and with good performance also during the P2 and PT periods, even though all the models overpredicted the number of statistically significant decreasing trends during the P2 period. Moreover, especially during the P1 period, both modeled and observational data indicated smaller reductions in SO42- concentrations compared with their gas-phase precursor (i.e., SO2), which could be mainly attributed to increased oxidant levels and pH-dependent cloud chemistry. An analysis of the trends in TNO3 concentrations indicated a 28%-39% and 29% mean relative reduction in TNO3 concentrations for the full period for model data (range of all the models) and observations, respectively. Further analysis of the trends in modeled HNO3 and particle nitrate (NO-3 ) concentrations revealed that the relative reduction in HNO3 was larger than that for NO-3 during the P1 period, which was mainly attributed to an increased availability of "free ammonia". By contrast, trends in modeled HNO3 and NO-3 concentrations were more comparable during the P2 period. Also, trends of TNHx concentrations were, in general, underpredicted by all models, with worse performance for the P1 period than for P2. Trends in modeled anthropogenic and biogenic secondary organic aerosol (ASOA and BSOA) concentrations together with the trends in available emissions of biogenic volatile organic compounds (BVOCs) were also investigated. A strong decrease in ASOA was indicated by all the models, following the reduction in anthropogenic non-methane VOC (NMVOC) precursors. Biogenic emission data provided by the modeling teams indicated a few areas with statistically significant increase in isoprene emissions and monoterpene emissions during the 1990-2010 period over Fennoscandia and eastern European regions (i.e., around 14 %-27 %), which was mainly attributed to the increase of surface temperature. However, the modeled BSOA concentrations did not linearly follow the increase in biogenic emissions. Finally, a comprehensive evaluation against positive matrix factorization (PMF) data, available during the second period (P2) at various European sites, revealed a systematic underestimation of the modeled SOA fractions of a factor of 3 to 11, on average, most likely because of missing SOA precursors and formation pathways, with reduced biases for the models that accounted for chemical aging of semi-volatile SOA components in the atmosphere.

air quality

monoterpene

aerosol composition

ammonium

isoprene

concentration (composition)

experimental study

trend analysis

Author

Giancarlo Ciarelli

University of Paris-Sud

Institut National de l'Environnement Industriel et des Risques (INERIS)

Carnegie Mellon University (CMU)

M. R. Theobald

Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (Ciemat)

Marta G. Vivanco

Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (Ciemat)

Matthias Beekmann

University of Paris-Sud

W. Aas

Norwegian Institute for Air Research (NILU)

Camilla Andersson

SMHI

Robert Bergström

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing

SMHI

Astrid Manders-Groot

Netherlands Organisation for Applied Scientific Research (TNO)

Florian Couvidat

Institut National de l'Environnement Industriel et des Risques (INERIS)

Mihaela Mircea

ENEA Centro Ricerche Bologna

S. Tsyro

Norwegian Meteorological Institute

H. Fagerli

Norwegian Meteorological Institute

Kathleen Mar

Institute for Advanced Sustainability Studies (IASS)

Valentin Raffort

École des Ponts ParisTech

Yelva Roustan

École des Ponts ParisTech

M. T. Pay

Centro Nacional de Supercomputacion

M. Schaap

Netherlands Organisation for Applied Scientific Research (TNO)

R. Kranenburg

Netherlands Organisation for Applied Scientific Research (TNO)

Mario Adani

ENEA Centro Ricerche Bologna

Gino Briganti

ENEA Centro Ricerche Bologna

Andrea Cappelletti

ENEA Centro Ricerche Bologna

Massimo D'Isidoro

ENEA Centro Ricerche Bologna

C. Cuvelier

Joint Research Centre (JRC), European Commission

Arineh Cholakian

Institut National de l'Environnement Industriel et des Risques (INERIS)

University of Paris-Sud

B. Bessagnet

Institut National de l'Environnement Industriel et des Risques (INERIS)

311121 China

P. Wind

Norwegian Meteorological Institute

University of Tromsø – The Arctic University of Norway

A. Colette

Institut National de l'Environnement Industriel et des Risques (INERIS)

Geoscientific Model Development

1991-959X (ISSN) 1991-9603 (eISSN)

Vol. 12 12 4923-4954

Subject Categories

Meteorology and Atmospheric Sciences

Physical Geography

Environmental Sciences

DOI

10.5194/gmd-12-4923-2019

More information

Latest update

7/2/2021 7