% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{Mallik:857542,
author = {Mallik, Chinmay and Tomsche, Laura and Bourtsoukidis,
Efstratios and Crowley, John N. and Derstroff, Bettina and
Fischer, Horst and Hafermann, Sascha and Hüser, Imke and
Javed, Umar and Keßel, Stephan and Lelieveld, Jos and
Martinez, Monica and Meusel, Hannah and Novelli, Anna and
Phillips, Gavin J. and Pozzer, Andrea and Reiffs, Andreas
and Sander, Rolf and Taraborrelli, Domenico and Sauvage,
Carina and Schuladen, Jan and Su, Hang and Williams,
Jonathan and Harder, Hartwig},
title = {{O}xidation processes in the eastern {M}editerranean
atmosphere: evidence from the modelling of
${HO}\<sub\>\<i\>x\</i\>\</sub\>$ measurements over
{C}yprus},
journal = {Atmospheric chemistry and physics},
volume = {18},
number = {14},
issn = {1680-7324},
address = {Katlenburg-Lindau},
publisher = {EGU},
reportid = {FZJ-2018-06533},
pages = {10825 - 10847},
year = {2018},
abstract = {The Mediterranean is a climatically sensitive region
located at the crossroads of air masses from three
continents: Europe, Africa, and Asia. The chemical
processing of air masses over this region has implications
not only for the air quality but also for the long-range
transport of air pollution. To obtain a comprehensive
understanding of oxidation processes over the Mediterranean,
atmospheric concentrations of the hydroxyl radical (OH) and
the hydroperoxyl radical (HO2) were measured during an
intensive field campaign (CYprus PHotochemistry EXperiment,
CYPHEX-2014) in the northwest of Cyprus in the summer of
2014. Very low local anthropogenic and biogenic emissions
around the measurement location provided a vantage point to
study the contrasts in atmospheric oxidation pathways under
highly processed marine air masses and those influenced by
relatively fresh emissions from mainland Europe.The CYPHEX
measurements were used to evaluate OH and HO2 simulations
using a photochemical box model (CAABA/MECCA) constrained
with CYPHEX observations of O3, CO, NOx, hydrocarbons,
peroxides, and other major HOx (OH+HO2) sources and sinks in
a low-NOx environment (<100pptv of NO). The model
simulations for OH agreed to within $10\%$ with in situ OH
observations. Model simulations for HO2 agreed to within
$17\%$ of the in situ observations. However, the model
strongly under-predicted HO2 at high terpene concentrations,
this under-prediction reaching up to $38\%$ at the highest
terpene levels. Different schemes to improve the agreement
between observed and modelled HO2, including changing the
rate coefficients for the reactions of terpene-generated
peroxy radicals (RO2) with NO and HO2 as well as the
autoxidation of terpene-generated RO2 species, are explored
in this work. The main source of OH in Cyprus was its
primary production from O3 photolysis during the day and
HONO photolysis during early morning. Recycling contributed
about one-third of the total OH production, and the maximum
recycling efficiency was about 0.7. CO, which was the
largest OH sink, was also the largest HO2 source. The lowest
HOx production and losses occurred when the air masses had
higher residence time over the oceans.},
cin = {IEK-8},
ddc = {550},
cid = {I:(DE-Juel1)IEK-8-20101013},
pnm = {243 - Tropospheric trace substances and their
transformation processes (POF3-243)},
pid = {G:(DE-HGF)POF3-243},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000440515900001},
doi = {10.5194/acp-18-10825-2018},
url = {https://juser.fz-juelich.de/record/857542},
}