Abstract.
The
major
bridge
linking
satellite-derived
vertical
column
densities
(VCDs)
of
nitrogen
dioxide
(NO2)
with
ground-level
concentration
is
theoretically
the
NO2
mixing
height
(NMH).
Various
meteorological
parameters
have
been
used
as
a
proxy
NMH
in
existing
studies.
This
study
developed
nested
machine
learning
model
to
convert
VCDs
into
concentrations
across
China
using
Geostationary
Environmental
Monitoring
Spectrometer
(GEMS)
measurements.
was
designed
directly
incorporate
methodological
framework
and
explore
its
impact
on
performance.
inner
predicted
from
parameters,
which
were
then
input
main
predict
VCDs.
inclusion
significantly
enhanced
accuracy
estimating
concentration,
reducing
bias
improving
R²
values
0.93
10-fold
cross-validation
0.99
fully-trained
model.
Furthermore,
identified
second
most
important
predictor
variable,
following
NO2.
Subsequently,
data
analyzed
subregions
varying
geolocations
urbanization
levels.
Highly
populated
areas
typically
experienced
peak
during
early
morning
rush
hours,
whereas
categorized
lightly
observed
slight
increase
levels
one
or
two
hours
later,
likely
due
regional
pollutant
dispersion
urban
sources.
underscores
importance
incorporating
satellite
measurements
highlights
significant
advantages
geostationary
satellites
providing
detailed
air
pollution
information
at
an
hourly
resolution.
Heliyon,
Journal Year:
2024,
Volume and Issue:
10(7), P. e28152 - e28152
Published: March 21, 2024
The
concentration
of
gases
in
the
atmosphere
is
a
topic
growing
concern
due
to
its
effects
on
health,
ecosystems
etc.
Its
monitoring
commonly
carried
out
through
ground
stations
which
offer
high
precision
and
temporal
resolution.
However,
countries
with
few
stations,
such
as
Ecuador,
these
data
fail
adequately
describe
spatial
variability
pollutant
concentrations.
Remote
sensing
have
great
potential
solve
this
complication.
This
study
evaluates
spatiotemporal
distribution
nitrogen
dioxide
(NO2)
ozone
(O3)
concentrations
Quito
Cuenca,
using
obtained
from
ground-based
Sentinel-5
Precursor
mission
sources
during
years
2019
2020.
Moreover,
Linear
Regression
Model
(LRM)
was
employed
analyze
correlation
between
satellite
datasets,
revealing
positive
associations
for
O3
(R2
=
0.83,
RMSE
0.18)
NO2
0.25)
Quito;
0.74,
0.23)
NO2,
0.73,
Cuenca.
agreement
datasets
analyzed
by
employing
intra-class
coefficient
(ICC),
reflecting
good
them
(ICC
≥0.57);
Bland
Altman
coefficients,
showed
low
bias
that
more
than
95%
differences
are
within
limits
agreement.
Furthermore,
investigated
impact
COVID-19
pandemic-related
restrictions,
social
distancing
isolation,
atmospheric
conditions.
categorized
into
three
periods
2020:
before
(from
January
1st
March
15th),
16th
May
17th),
after
18th
December
31st).
A
51%
decrease
recorded
while
experienced
14.7%
decrease.
tropospheric
column
decreased
27.3%
Cuenca
15.1%
Quito.
an
increasing
trend,
rising
0.42%
0.11%
respectively,
14.4%.
increase
10.5%.
Finally,
reduction
chemical
species
consequence
mobility
restrictions
highlighted.
compared
station
Despite
differing
units
preventing
validation,
it
verified
Sentinel-5P
satellite's
effectiveness
anomaly
detection.
Our
research's
value
lies
applicability
developing
countries,
may
lack
extensive
networks,
demonstrating
use
technology
urban
planning.
Remote Sensing,
Journal Year:
2025,
Volume and Issue:
17(1), P. 121 - 121
Published: Jan. 2, 2025
NO2
primarily
originates
from
natural
and
anthropogenic
emissions.
Given
China’s
vast
territory
significant
differences
in
topography
meteorological
conditions,
a
detailed
understanding
of
the
impacts
weather
human
emissions
different
regions
is
essential.
This
study
employs
Kolmogorov–Zurbenko
(KZ)
filtering
stepwise
multiple
linear
regression
to
isolate
effects
conditions
on
tropospheric
vertical
column
densities.
Long
term
trends
indicate
an
overall
decline,
with
contribution
rates
exceeding
90%
Shanghai,
Changchun,
Urumqi,
Shijiazhuang,
Wuhan,
where
interannual
variations
are
driven
by
In
Guangzhou,
rate
exceeds
100%,
highlighting
impact
factors
this
region,
although
somewhat
mitigate
their
effect
NO2.
Chengdu,
also
play
role.
Seasonal
display
U-shaped
trend,
there
seasonal
among
regions.
Meteorological
Changchun
Chengdu
below
36.90%
contributions
exceed
63.10%.
indicates
that
changes
less
influenced
than
activities,
dominating.
other
regions,
greater
those
activities.
Frontiers in Sustainable Energy Policy,
Journal Year:
2025,
Volume and Issue:
3
Published: Jan. 7, 2025
The
global
phenomenon
of
environmental
deterioration
often
signifies
the
increase
in
ecological
footprint
and
emissions
levels
that
adversely
affect
earth's
biocapacity.
This
results
from
use
substantial
fossil
fuels
energy
sources,
industrialization,
extensive
economic
activities
developing
countries.
In
this
context,
study
examine
impact
depletion,
technical
cooperation
grants,
on
load
capacity
factor
Pakistan
1970
to
2022.
To
accomplish
this,
employs
innovative
dynamic
autoregressive
distributed
lag
(ARDL)
simulation
approach,
providing
fresh
insights
contrast
with
earlier
conclusions.
authors
contribute
focusing
supply-side
dynamics
indicators,
namely
capacity,
viewpoint
Pakistan,
distinguishing
our
research
existing
academic
publications.
Our
results,
however,
demonstrate
a
markedly
favorable
effect
grants
enhancing
safety.
Furthermore,
depletion
industrialization
dynamics,
exacerbating
deterioration.
Moreover,
conducts
sensitivity
analysis
by
comparing
obtained
using
those
derived
footprints.
Consequently,
we
advocate
for
development
realistic
policies
mitigate
adverse
impacts
via
effective
sources
preserve
biodiversity.
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(16), P. 9645 - 9665
Published: Aug. 30, 2024
Abstract.
The
major
link
between
satellite-derived
vertical
column
densities
(VCDs)
of
nitrogen
dioxide
(NO2)
and
ground-level
concentrations
is
theoretically
the
NO2
mixing
height
(NMH).
Various
meteorological
parameters
have
been
used
as
a
proxy
for
NMH
in
existing
studies.
This
study
developed
nested
XGBoost
machine
learning
model
to
convert
VCDs
into
across
China
using
Geostationary
Environmental
Monitoring
Spectrometer
(GEMS)
measurements.
was
designed
directly
incorporate
methodological
framework
estimate
concentrations.
inner
predicted
from
parameters,
which
were
then
input
main
predict
its
VCDs.
inclusion
significantly
enhanced
accuracy
concentration
estimates;
i.e.,
R2
values
improved
0.73
0.93
10-fold
cross-validation
0.88
0.99
fully
trained
model.
Furthermore,
identified
second
most
important
predictor
variable,
following
NO2.
Subsequently,
data
analyzed
subregions
with
varying
geographic
locations
urbanization
levels.
Highly
populated
areas
typically
experienced
peak
during
early
morning
rush
hour,
whereas
categorized
lightly
observed
slight
increase
levels
1
or
2
h
later,
likely
due
regional
pollutant
dispersion
urban
sources.
underscores
importance
incorporating
estimating
satellite
measurements
highlights
significant
advantages
geostationary
satellites
providing
detailed
air
pollution
information
at
an
hourly
resolution.
Atmosphere,
Journal Year:
2025,
Volume and Issue:
16(1), P. 45 - 45
Published: Jan. 3, 2025
The
increasingly
severe
nocturnal
ozone
enhancement
(NOE)
event
pollution
is
widely
concerning.
Therefore,
based
on
the
observed
hourly
O3
concentrations
from
2015
to
2023,
this
study
analyzes
characteristics
of
NOE
events
over
Putian
City.
analysis
results
show
that
frequency
City
high,
at
about
127
days
annually,
with
a
high
in
April
and
low
July
August.
Most
corresponded
peak
concentration
(NOP)
<120
μg/m3.
Moreover,
they
mainly
occurred
between
1:00–3:00
7:00.
physicochemical
processes
April,
October,
November
2020
were
simulated
using
Weather
Research
Forecasting
(WRF,
version
4.3.3)
model
coupled
Community
Multiscale
Air
Quality
(CMAQ,
5.4)
model.
suggest
transport,
especially
horizontal
transport
eastern
sea
Zhejiang
Province
vertical
upper
atmosphere,
could
be
major
cause
Furthermore,
movement
zone,
along
aggregation
due
weakened
dry
deposition
influence
stable
boundary
layer
obstructed
by
mountain
terrain,
significantly
influenced
overall
concentration.
Thus,
stem
interaction
among
these
processes.
emphasize
importance
control
implementation
strict
joint
regional
measures
for
improve
air
quality.