Sensitivity of air pollution simulations with LOTOS-EUROS to the temporal distribution of anthropogenic emissions
In this study the sensitivity of the model performance of the chemistry transport model (CTM) LOTOS-EUROS to the description of the temporal variability of emissions was investigated. Currently the temporal release of anthropogenic emissions is described by European average diurnal, weekly and seaso...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/14/939/2014/acp-14-939-2014.pdf |
| Summary: | In this study the sensitivity of the model performance of the chemistry
transport model (CTM) LOTOS-EUROS to the description of the temporal
variability of emissions was investigated. Currently the temporal release of
anthropogenic emissions is described by European average diurnal, weekly and
seasonal time profiles per sector. These default time profiles largely
neglect the variation of emission strength with activity patterns, region,
species, emission process and meteorology. The three sources dealt with in
this study are combustion in energy and transformation industries (SNAP1),
nonindustrial combustion (SNAP2) and road transport (SNAP7). First of all, the
impact of neglecting the temporal emission profiles for these SNAP
categories on simulated concentrations was explored. In a second step, we
constructed more detailed emission time profiles for the three categories
and quantified their impact on the model performance both separately as well as
combined. The performance in comparison to observations for Germany was
quantified for the pollutants NO<sub>2</sub>, SO<sub>2</sub> and PM<sub>10</sub> and compared to a
simulation using the default LOTOS-EUROS emission time profiles. The
LOTOS-EUROS simulations were performed for the year 2006 with a temporal
resolution of 1 h and a horizontal resolution of approximately
25 × 25km<sup>2</sup>.
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In general the largest impact on the model performance was found when
neglecting the default time profiles for the three categories. The daily
average correlation coefficient for instance decreased by 0.04 (NO<sub>2</sub>),
0.11 (SO<sub>2</sub>) and 0.01 (PM<sub>10</sub>) at German urban background stations compared
to the default simulation. A systematic increase in the correlation
coefficient is found when using the new time profiles. The size of the
increase depends on the source category, component and station. Using
national profiles for road transport showed important improvements in the
explained variability over the weekdays as well as the diurnal cycle for
NO<sub>2</sub>. The largest impact of the SNAP1 and 2 profiles were found for
SO<sub>2</sub>. When using all new time profiles simultaneously in one simulation,
the daily average correlation coefficient increased by 0.05 (NO<sub>2</sub>), 0.07
(SO<sub>2</sub>) and 0.03 (PM<sub>10</sub>) at urban background stations in Germany. This
exercise showed that to improve the performance of a CTM, a better
representation of the distribution of anthropogenic emission in time is
recommendable. This can be done by developing a dynamical emission model
that takes into account regional specific factors and meteorology. |
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| ISSN: | 1680-7316 1680-7324 |