In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 21, No. 7 ( 2021-04-06), p. 5269-5288
Abstract:
Abstract. The evaluation of chemical transport models, CTMs, is
essential for the assessment of their performance regarding the physical and
chemical parameterizations used. While regional CTMs have been widely used
and evaluated over Europe, their validation over Greece is limited. In this
study, we investigate the performance of the Long Term Ozone Simulation
European Operational Smog (LOTOS-EUROS) v2.2.001 regional chemical transport
model in simulating nitrogen dioxide, NO2, over Greece from June to
December 2018. In situ NO2 measurements obtained from 14 stations
of the National Air Pollution Monitoring Network are compared with surface
simulations over the two major cities of Greece, Athens and Thessaloniki.
Overall the LOTOS-EUROS NO2 surface simulations compare very well to
the in situ measurements showing a mild underestimation of the measurements
with a mean relative bias of ∼-10 %, a high spatial
correlation coefficient of 0.86 and an average temporal correlation of 0.52.
The CTM underestimates the NO2 surface concentrations during daytime by
∼-50 ± 15 %, while it slightly overestimates during
night-time ∼ 10 ± 35 %. Furthermore, the LOTOS-EUROS
tropospheric NO2 columns are evaluated against ground-based multi-axis
differential optical absorption spectroscopy (MAX-DOAS) NO2
measurements in Athens and Thessaloniki. We report that the CTM tropospheric
NO2 column simulations over both urban and rural locations represent
the diurnal patterns and hourly levels for both summer and winter seasons
satisfactorily. The relative biases range between ∼ −2 % and
−35 %, depending on season and relative NO2 load observed. Finally,
the CTM was assessed also against space-borne Sentinel-5
Precursor (S5P) carrying the Tropospheric Monitoring Instrument (TROPOMI) tropospheric NO2
observations. We conclude that LOTOS-EUROS simulates extremely well the
tropospheric NO2 patterns over the region with very high spatial
correlation of 0.82 on average, ranging between 0.66 and 0.95, with negative biases in the summer and positive in the winter.
Updated emissions for the simulations and model improvements when extreme
values of boundary layer height are encountered are further suggested.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-21-5269-2021
DOI:
10.5194/acp-21-5269-2021-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2021
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
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