Atmospheric chemistry and physics,
Год журнала:
2024,
Номер
24(16), С. 9555 - 9572
Опубликована: Авг. 29, 2024
Abstract.
The
fraction
of
urban
volatile
organic
compound
(VOC)
emissions
attributable
to
fossil
fuel
combustion
has
been
declining
in
many
parts
the
world,
resulting
a
need
better
constrain
other
anthropogenic
sources
these
emissions.
During
National
Institute
Environmental
Research
(NIER)
and
Aeronautics
Space
Administration
(NASA)
Korea-United
States
Air
Quality
(KORUS-AQ)
field
study
Seoul,
South
Korea,
during
May–June
2016,
air
quality
models
underestimated
ozone,
formaldehyde,
peroxyacetyl
nitrate
(PAN),
indicating
an
underestimate
VOCs
inventory.
Here,
we
use
aircraft
observations
interpreted
with
GEOS-Chem
chemical
transport
model
(version
13.4.0)
assess
for
increases
VOC
revised
mechanism
improve
treatment
speciation
chemistry.
We
find
that
largest
needed
are
compounds
associated
products,
liquefied
petroleum
gas
(LPG)
natural
emissions,
long-range
transport.
Revising
chemistry
match
observed
together
increasing
species
increased
calculated
OH
reactivity
by
+2
s−1
ozone
production
ppb
h−1.
Ozone
+6
below
2
km
+9
at
surface,
formaldehyde
acetaldehyde
+30
%
+120
aloft,
respectively,
all
agreement
observations.
larger
increase
was
attributed
ethanol
which
found
be
as
important
isoprene
or
alkenes.
significantly
reduced
PAN
bias.
additional
unmeasured
VOCs,
however,
indicated
remaining
bias
−0.8
−57
−52
higher
peroxynitrates
(PNs)
alkyl
nitrates
(ANs),
respectively.
added
represent
six
PNs
from
but
were
unable
account
majority
missing
PNs.
However,
four
modeled
concentrations
similar
commonly
measured
(>
PAN)
should
future
campaigns
considered
emission
(e.g.,
fires).
hypothesize
oxygenated
(OVOCs)
such
≥
C5
aldehydes
cooking
and/or
alkenes
products
could
produce
both
ANs
biases.
Emerging
research
on
will
soon
allow
modeling
their
impact
local
regional
photochemistry.
Particulate
nitrate
([Formula:
see
text])
has
long
been
considered
a
permanent
sink
for
NOx
(NO
and
NO2),
removing
gaseous
pollutant
that
is
central
to
air
quality
influences
the
global
self-cleansing
capacity
of
atmosphere.
Evidence
emerging
photolysis
[Formula:
text]
can
recycle
HONO
back
gas
phase
with
potentially
important
implications
tropospheric
ozone
OH
budgets;
however,
there
are
substantial
discrepancies
in
"renoxification"
rate
constants.
Using
aircraft
ground-based
observations
remote
Atlantic
troposphere,
we
show
evidence
renoxification
occurring
on
mixed
marine
aerosols
an
efficiency
increases
relative
humidity
decreases
concentration
text],
thus
largely
reconciling
very
large
constants
found
across
multiple
laboratory
field
studies.
Active
release
from
aerosol
atmospheric
oxidants
such
as
O3
both
polluted
clean
environments.
Atmospheric chemistry and physics,
Год журнала:
2023,
Номер
23(2), С. 1227 - 1257
Опубликована: Янв. 24, 2023
Abstract.
Satellite-based
retrievals
of
tropospheric
NO2
columns
are
widely
used
to
infer
NOx
(≡
NO
+
NO2)
emissions.
These
rely
on
model
information
for
the
vertical
distribution
NO2.
The
free
background
above
2
km
is
particularly
important
because
sensitivity
increases
with
altitude.
Free
also
has
a
strong
effect
OH
and
ozone
concentrations.
Here
we
use
observations
from
three
aircraft
campaigns
(SEAC4RS,
DC3,
ATom)
four
atmospheric
chemistry
models
(GEOS-Chem,
GMI,
TM5,
CAMS)
evaluate
capabilities
simulating
in
troposphere
attribute
it
sources.
measurements
during
Studies
Emissions
Atmospheric
Composition,
Clouds,
Climate
Coupling
by
Regional
Surveys
(SEAC4RS)
Deep
Convective
Clouds
Chemistry
(DC3)
over
southeastern
U.S.
summer
show
increasing
concentrations
upper
10
km,
which
not
replicated
GEOS-Chem,
although
consistent
measurements.
Using
concurrent
NO,
NO2,
DC3
flight
thunderstorm
outflow,
that
biased
high,
plausibly
due
interference
thermally
labile
reservoirs
such
as
peroxynitric
acid
(HNO4)
methyl
peroxy
nitrate
(MPN).
We
find
calculated
NO–NO2
photochemical
steady
state
(PSS)
more
reliable
profiles
models.
GEOS-Chem
reproduces
shape
PSS-inferred
throughout
SEAC4RS
but
overestimates
about
factor
2.
underestimates
MPN
alkyl
concentrations,
suggesting
missing
organic
chemistry.
On
other
hand,
standard
Tomography
Mission
(ATom)
Pacific
Atlantic
oceans,
indicating
source
oceans.
can
account
this
including
photolysis
particulate
sea
salt
aerosols
at
rates
inferred
laboratory
studies
field
nitrous
(HONO)
Atlantic.
median
column
density
ATom
campaign
1.7
±
0.44
×
1014
molec.
cm−2,
simulated
range
1.4–2.4
implying
uncertainty
using
modeled
clean
areas
stratosphere–troposphere
separation
1
cm−2.
lightning
main
primary
tropics
southern
midlatitudes,
emissions
dominate
northern
midlatitudes
winter
Particulate
up
5
ppbv
(parts
per
billion
volume)
extratropics
model,
would
largely
correct
low
bias
relative
ozonesonde
observations.
Global
increase
19
%.
contribution
observed
satellites
contiguous
25
11
%
65
9
summer,
according
profiles.
This
needs
be
accounted
when
deriving
satellite
Atmospheric chemistry and physics,
Год журнала:
2022,
Номер
22(5), С. 3275 - 3302
Опубликована: Март 11, 2022
Abstract.
Co-occurrences
of
high
concentrations
PM2.5
and
ozone
(O3)
have
been
frequently
observed
in
haze-aggravating
processes
the
North
China
Plain
(NCP)
over
past
few
years.
Higher
O3
on
hazy
days
were
hypothesized
to
be
related
nitrous
acid
(HONO),
but
key
sources
HONO
enhancing
during
remain
unclear.
We
added
six
potential
sources,
i.e.,
four
ground-based
(traffic,
soil,
indoor
emissions,
NO2
heterogeneous
reaction
ground
surface
(Hetground))
two
aerosol-related
(the
aerosol
surfaces
(Hetaerosol)
nitrate
photolysis
(Photnitrate))
into
WRF-Chem
model
designed
23
simulation
scenarios
explore
unclear
sources.
The
results
indicate
that
producing
enhancements
showed
a
rapid
decrease
with
height,
while
NO
+
OH
decreased
slowly
height.
Photnitrate
contributions
enhanced
aggravated
pollution
levels.
enhancement
due
was
about
10
times
greater
than
clean
dominated
daytime
(∼
30
%–70
%
when
ratio
frequency
(Jnitrate)
gas
nitric
(JHNO3)
equals
30)
at
higher
layers
(>800
m).
Compared
days,
contribution
daily
maximum
8
h
averaged
(DMA8)
increased
by
1
magnitude
process.
contributed
only
∼
5
Jnitrate/JHNO3
%–50
near
NCP
days.
Surface
volatile
organic
compound-sensitive
chemistry,
altitudes
m)
NOx-sensitive
chemistry.
had
limited
impact
(<15
%)
even
120.
These
suggest
significant
formation,
more
comprehensive
studies
atmosphere
are
still
needed.
Atmospheric chemistry and physics,
Год журнала:
2022,
Номер
22(2), С. 1035 - 1057
Опубликована: Янв. 21, 2022
Abstract.
In
the
summer
of
2018,
a
comprehensive
field
campaign,
with
measurements
on
HONO
and
related
parameters,
was
conducted
at
foot
(150
m
a.s.l.)
summit
Mt.
Tai
(1534
in
central
North
China
Plain
(NCP).
With
implementation
0-D
box
model,
budget
six
additional
sources
its
role
radical
chemistry
station
were
explored.
We
found
that
model
default
source,
NO
+
OH,
could
only
reproduce
13
%
observed
HONO,
leading
to
strong
unknown
source
strength
up
3
ppbv
h−1.
Among
sources,
NO2
uptake
ground
surface
dominated
(∼
70
%)
nighttime
formation,
photo-enhanced
reaction
80
daytime
formation.
Their
contributions
sensitive
mixing
layer
height
(MLH)
used
for
parameterizations,
highlighting
importance
reasonable
MLH
exploring
ground-level
formation
models
necessity
gradient
measurements.
A
ΔHONO/ΔNOx
ratio
0.7
direct
emissions
from
vehicle
exhaust
inferred,
new
method
quantify
contribution
observations
proposed
discussed.
Aerosol-derived
including
aerosol
particulate
nitrate
photolysis,
did
not
lead
significant
their
lower
than
OH.
photolysis
early
morning
initialized
photochemistry
station.
It
also
substantial
throughout
daytime,
higher
O3
OH
initiation.
Moreover,
we
atmospheric
oxidizing
capacity
while
modeled
NO3
appeared
be
night.
Peaks
time
series
average
diurnal
variation
reached
22
9
pptv,
respectively.
NO3-induced
reactions
contribute
18
potential
(P(HNO3))
11
isoprene
(C5H8)
oxidation
whole
day.
At
night,
led
51
44
P(HNO3)
or
C5H8
oxidation,
respectively,
implying
significantly
affect
secondary
organic
inorganic
this
high-O3
region.
Considering
severe
pollution
NCP
very
limited
measurements,
suggest
besides
HOx
primary
precursors
(O3,
alkenes,
etc.),
should
understand
air
similar
regions.
Frontiers of Environmental Science & Engineering,
Год журнала:
2022,
Номер
17(4)
Опубликована: Ноя. 1, 2022
Abstract
Nitrate
is
an
important
component
of
atmospheric
particulate
matter
and
affects
air
quality,
climate,
human
health,
the
ecosystem.
was
previously
considered
a
permanent
sink
for
nitrogen
oxides
(NO
x
).
However,
this
viewpoint
has
been
challenged
in
recent
years
because
growing
research
evidence
shown
transformation
nitrate
into
NO
(i.e.,
renoxification).
The
photolysis
nitrate/HNO
3
,
especially
phase
or
adsorbed
on
particles,
can
be
significant
renoxification
process
atmosphere.
formation
aerosol
not
only
change
diurnal
variation
but
also
provide
long-distance
transport
form
nitrate,
which
local
regional
chemistry
quality.
This
review
summarizes
advances
fundamental
understanding
under
various
conditions,
with
focus
mechanisms
key
factors
affecting
process.
implications
are
discussed
future
recommended.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(43)
Опубликована: Авг. 19, 2022
The
nitrogen
oxides
(NOx)
formed
by
photochemical
reaction
of
surface
nitrates
raise
significant
concerns.
However,
little
is
known
about
the
effect
visible
light
(>380
nm)
on
nitrate
decomposition
and
mechanism.
Herein,
investigated
under
light.
results
indicate
that
photocatalysis
contributes
significantly
to
decomposition.
Monodentate
(m-NO3-
)
can
be
decomposed
into
NOx
photogenerated
electrons
starting
from
weakly
coordinated
N-O
bond.
Water
vapor
promotes
generation
because
more
stable
bidentate
(b-NO3-
will
converted
m-NO3-
hydroxyl
groups
through
hydrogen
bonding
interactions.
Alternatively,
b-NO3-
directly
NO2-
NO
attack,
but
this
process
subject
photocatalytic
oxidation.
This
work
brings
a
new
focus
atmospheric
sources
provides
nuanced
understanding
processes.
Geophysical Research Letters,
Год журнала:
2024,
Номер
51(5)
Опубликована: Март 8, 2024
Abstract
Tropospheric
ozone
is
an
air
pollutant
and
a
greenhouse
gas
whose
anthropogenic
production
limited
principally
by
the
supply
of
nitrogen
oxides
(NO
x
)
from
combustion.
in
northern
hemisphere
has
been
rising
despite
flattening
NO
emissions
recent
decades.
Here
we
propose
that
this
sustained
increase
could
result
photolysis
nitrate
particles
(pNO
3
−
to
regenerate
.
Including
pNO
GEOS‐Chem
atmospheric
chemistry
model
improves
consistency
with
observations.
Our
simulations
show
concentrations
have
increased
since
1960s
because
ammonia
falling
SO
2
emissions,
augmenting
extratropics
about
50%
better
match
observed
trend.
will
likely
continue
through
2050,
which
would
drive
continued
even
as
decrease.
More
work
needed
understand
mechanism
rates
photolysis.