1. Changes in black carbon emissions over Europe due to COVID-19 lockdownsNikolaos Evangeliou, Stephen M. Platt, Sabine Eckhardt, Cathrine Lund Myhre, Paolo Laj, L. Alados-Arboledas, John Backman, Benjamin T. Brem, Markus Fiebig, Jesús Yus-Díez, 2021, izvirni znanstveni članek Opis: Abstract. Following the emergence of the severe acute respiratory syndrome coronavirus
2 (SARS-CoV-2) responsible for COVID-19 in December 2019 in Wuhan (China)
and its spread to the rest of the world, the World Health Organization
declared a global pandemic in March 2020. Without effective treatment in the
initial pandemic phase, social distancing and mandatory quarantines were
introduced as the only available preventative measure. In contrast to the
detrimental societal impacts, air quality improved in all countries in which
strict lockdowns were applied, due to lower pollutant emissions. Here we
investigate the effects of the COVID-19 lockdowns in Europe on ambient black
carbon (BC), which affects climate and damages health, using in situ
observations from 17 European stations in a Bayesian inversion framework. BC
emissions declined by 23 kt in Europe (20 % in Italy, 40 % in Germany,
34 % in Spain, 22 % in France) during lockdowns compared to the same
period in the previous 5 years, which is partially attributed to COVID-19
measures. BC temporal variation in the countries enduring the most drastic
restrictions showed the most distinct lockdown impacts. Increased particle
light absorption in the beginning of the lockdown, confirmed by assimilated
satellite and remote sensing data, suggests residential combustion was the
dominant BC source. Accordingly, in central and Eastern Europe, which
experienced lower than average temperatures, BC was elevated compared to the
previous 5 years. Nevertheless, an average decrease of 11 % was seen
for the whole of Europe compared to the start of the lockdown period, with
the highest peaks in France (42 %), Germany (21 %), UK (13 %), Spain
(11 %) and Italy (8 %). Such a decrease was not seen in the previous
years, which also confirms the impact of COVID-19 on the European emissions
of BC.
Ključne besede: black carbon, covid-19, emissions, Europe
Objavljeno v RUNG: 13.05.2024; Ogledov: 112; Prenosov: 3
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2. Elucidating local pollution and site representativeness at the Jungfraujoch, Switzerland through parallel aerosol measurements at an adjacent mountain ridgeNicolas Bukowiecki, Benjamin Brem, Günther Wehrle, Griša Močnik, Stéphane Affolter, Markus Christian Leuenberger, Martine Collaud Coen, Maxime Hervo, Urs Baltensperger, Martin Gysel, 2021, izvirni znanstveni članek Opis: Many long-term air pollution and climate monitoring stations face the issue of increasing anthropogenic activities in their vicinity. Furthermore, the spatial representativeness of the sites is often not entirely understood especially in mountainous terrain with complex topographic features. This study presents a 5-year comparison of parallel aerosol measurements (total particle number concentration and equivalent black carbon mass concentration) at the Jungfraujoch in the Swiss Alps (JFJ, 3580 m a.s.l.), and an adjacent mountain ridge, the Jungfrau East Ridge (JER, 3705 m a.s.l.), in 1000 m air-line distance to the main site. The parallel aerosol measurements reveal characteristic differences in the diurnal variations between the two sites under certain specific meteorological conditions. Our analysis estimates that on 20-40% of the days local activities at the Jungfraujoch have a clear influence on the measured time series of the total aerosol number concentration and the equivalent black carbon mass concentration. This influence is mainly seen in form of strong isolated spikes rather than by an increase in the on-site background concentration. They can thus be flagged during the data quality assurance process and filtered from those measurement parameters available at high time resolution. Removing the spikes from the original time series results in daily mean values for the total aerosol number concentration and equivalent black carbon mass concentration that are 5-10 % lower compared to the original signals. During nighttime with hardly any local pollution sources that cause spikes this percentage decreases towards 0%. The signal baselines at the Jungfraujoch and Jungfrau East Ridge correlate well during more than 50% of the days.
Ključne besede: aerosol long-term monitoring, equivalent black carbon, aerosol number concentration, spatial variation
Objavljeno v RUNG: 15.03.2021; Ogledov: 1995; Prenosov: 71
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