Atmospheric chemistry and physics,
Год журнала:
2023,
Номер
23(7), С. 4091 - 4104
Опубликована: Апрель 5, 2023
Abstract.
Aerosol
particles
play
important
roles
in
air
quality
and
global
climate
change.
In
this
study,
we
analyze
the
measurements
of
particle
size
distribution
from
12
March
to
6
April
2016
Beijing
characterize
new
formation
(NPF)
using
observational
data
sulfuric
acid,
meteorological
parameters,
solar
radiation,
mass
concentration
fine
(PM2.5,
particulate
matter
with
diameters
less
than
2.5
µm).
During
26
d
campaign,
11
events
are
identified
obvious
bursts
sub-3
nm
number
concentrations
subsequent
growth
these
nucleated
particles.
It
is
found
that
acid
does
not
have
a
significant
difference
between
NPF
event
non-event
days.
Low
relative
humidity
(RH)
high
daily
total
radiation
appear
be
favorable
for
occurrence
events,
which
quite
campaign.
The
simulations
four
nucleation
schemes,
i.e.,
H2SO4–H2O
binary
homogeneous
(BHN),
H2SO4–H2O–NH3
ternary
(THN),
H2SO4–H2O–ion
ion-mediated
(BIMN),
H2SO4–H2O–NH3–ion
(TIMN),
based
on
chemistry
transport
model
(GEOS-Chem)
coupled
an
advanced
microphysics
(APM)
model,
conducted
study
process.
Our
comparisons
indicate
BHN
scheme
BIMN
significantly
underestimate
observed
concentrations,
THN
captures
most
days
well
but
fails
capture
noticeable
increase
18
1
April.
TIMN
has
improvement
terms
rates.
This
provides
basis
further
understanding
mechanism
Beijing.
Chemical Reviews,
Год журнала:
2023,
Номер
123(4), С. 1635 - 1679
Опубликована: Янв. 11, 2023
Organic
peroxides
(POs)
are
organic
molecules
with
one
or
more
peroxide
(−O–O−)
functional
groups.
POs
commonly
regarded
as
chemically
labile
termination
products
from
gas-phase
radical
chemistry
and
therefore
serve
temporary
reservoirs
for
oxidative
radicals
(HOx
ROx)
in
the
atmosphere.
Owing
to
their
ubiquity,
active
gas-particle
partitioning
behavior,
reactivity,
key
reactive
intermediates
atmospheric
multiphase
processes
determining
life
cycle
(formation,
growth,
aging),
climate,
health
impacts
of
aerosol.
However,
there
remain
substantial
gaps
origin,
molecular
diversity,
fate
due
complex
nature
dynamic
behavior.
Here,
we
summarize
current
understanding
on
POs,
a
focus
identification
quantification,
state-of-the-art
analytical
developments,
molecular-level
formation
mechanisms,
chemical
transformation
pathways,
well
environmental
impacts.
We
find
that
interactions
SO2
transition
metal
ions
generally
fast
PO
pathways
liquid
water,
lifetimes
estimated
be
minutes
hours,
while
hydrolysis
is
particularly
important
α-substituted
hydroperoxides.
Meanwhile,
photolysis
thermolysis
likely
minor
sinks
POs.
These
distinctly
different
fates,
such
reaction
OH
radicals,
which
highlights
need
understand
By
summarizing
advances
remaining
challenges
investigation
propose
future
research
priorities
regarding
fate,
Environmental Science & Technology,
Год журнала:
2022,
Номер
56(14), С. 9936 - 9946
Опубликована: Июнь 24, 2022
Atmospheric
new
particle
formation
significantly
affects
global
climate
and
air
quality
after
newly
formed
particles
grow
above
∼50
nm.
In
polluted
urban
atmospheres
with
1-3
orders
of
magnitude
higher
rates
than
those
in
clean
atmospheres,
growth
are
comparable
or
even
lower
for
reasons
that
were
previously
unclear.
Here,
we
address
the
slow
Beijing
advanced
measurements
size-resolved
molecular
composition
nanoparticles
using
thermal
desorption
chemical
ionization
mass
spectrometer
gas
precursors
nitrate
CI-APi-ToF.
A
model
combining
condensational
particle-phase
acid-base
chemistry
was
developed
to
explore
mechanisms.
The
8-40
nm
during
events
is
dominated
by
organics
(∼80%)
sulfate
(∼13%),
remainder
from
base
compounds,
nitrate,
chloride.
With
increase
sizes,
fraction
decreases,
while
slow-desorbed
organics,
organic
acids,
increases.
simulated
consistent
measured
results
most
cases,
they
both
indicate
vapors
H2SO4
major
pathway
reactions
play
a
minor
role.
comparison
high
concentrations
gaseous
sulfuric
acid
amines
cause
rates,
concentration
condensable
comparably
under
NOx
levels,
relatively
high-volatility
nitrogen-containing
oxidation
products
higher.
insufficient
lead
growth,
which
further
causes
low
survival
environments.
Thus,
some
extent,
counteract
impact
on
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(24), С. 10664 - 10674
Опубликована: Июнь 8, 2024
New
particle
formation
(NPF)
is
a
major
source
of
atmospheric
aerosol
particles,
including
cloud
condensation
nuclei
(CCN),
by
number
globally.
Previous
research
has
highlighted
that
NPF
less
frequent
but
more
intense
at
roadsides
compared
to
urban
background.
Here,
we
closely
examine
both
background
and
roadside
sites
in
Central
Europe.
We
show
the
concentration
oxygenated
organic
molecules
(OOMs)
greater
roadside,
OOMs
along
with
sulfuric
acid
onto
new
particles
sufficient
explain
growth
sites.
identify
hitherto
unreported
traffic-related
OOM
contributing
29%
16%
total
background,
respectively.
Critically,
this
undiscovered
an
essential
component
NPF.
Without
their
contribution
rates
subsequent
enhancements
survival,
>50
nm
produced
would
be
reduced
factor
21
site.
Reductions
hydrocarbon
emissions
from
road
traffic
may
thereby
reduce
numbers
CCN
counts.
Atmospheric chemistry and physics,
Год журнала:
2022,
Номер
22(18), С. 12207 - 12220
Опубликована: Сен. 19, 2022
Abstract.
During
the
COVID-19
lockdown,
dramatic
reduction
of
anthropogenic
emissions
provided
a
unique
opportunity
to
investigate
effects
reduced
activity
and
primary
on
atmospheric
chemical
processes
consequent
formation
secondary
pollutants.
Here,
we
utilize
comprehensive
observations
examine
response
new
particle
(NPF)
changes
in
cocktail.
We
find
that
main
clustering
process
was
unaffected
by
drastically
traffic
emissions,
rate
1.5
nm
particles
remained
unaltered.
However,
survival
probability
enhanced
due
an
increased
growth
(GR)
during
lockdown
period,
explaining
NPF
earlier
studies.
For
GR
at
1.5–3
nm,
sulfuric
acid
(SA)
contributor
high
temperatures,
whilst
there
were
unaccounted
contributing
vapors
low
temperatures.
3–7
7–15
oxygenated
organic
molecules
(OOMs)
played
major
role.
Surprisingly,
OOM
composition
volatility
insensitive
large
change
NOx
concentration;
instead
associated
rates
concentration
period
mostly
caused
oxidative
capacity.
Overall,
our
findings
suggest
limited
role
NPF.
Atmospheric chemistry and physics,
Год журнала:
2024,
Номер
24(3), С. 1873 - 1893
Опубликована: Фев. 12, 2024
Abstract.
New
particle
formation
contributes
significantly
to
the
number
concentration
of
ultrafine
particles
(UFPs,
d
≤
100
nm)
and
has
a
great
impact
on
human
health
global
climate.
Iodine
oxoacids
(HIOx,
including
iodic
acid,
HIO3,
iodous
HIO2)
have
been
observed
in
pristine
regions
proved
dominate
new
(NPF)
at
some
sites.
However,
knowledge
HIOx
polluted
urban
areas
is
rather
limited.
Here,
we
conducted
long-term
measurements
gaseous
iodine
sulfuric
acid
Beijing
from
January
2019
October
2021
also
Nanjing
March
February
2020
investigated
contribution
UFP
both
environments.
HIO3
highest
summer,
up
2.85
×
106
2.78
cm−3
Nanjing,
respectively,
lowest
winter
by
96
%
75
%,
respectively.
exhibits
more
prominent
variation
than
H2SO4
shows
clear
diurnal
pattern
sites
with
daily
maximum
around
noontime,
similar
atmospheric
temperature,
solar
radiation,
ozone
(O3)
levels.
HIO2
same
seasonal
trend
as
but
overall
about
an
order
magnitude
lower
concentration.
Back
trajectory
analysis
suggests
that
sources
for
inland
species
could
be
mix
marine
terrestrial
origins,
having
peak
emission
warm
seasons.
While
growth
marginal
our
results
demonstrate
enhances
survival
probability
sub-3
nm
40
(median)
occasionally
NPF
events,
suggesting
are
significant
contributor
UFPs
areas.
As
per-molecule
basis,
propose
sum
used
estimate
inorganic
origin
atmospheres
amount
HIOx.
Environmental Science & Technology,
Год журнала:
2023,
Номер
57(20), С. 7764 - 7776
Опубликована: Май 8, 2023
Oxygenated
organic
molecules
(OOMs)
are
critical
intermediates
linking
volatile
compound
oxidation
and
secondary
aerosol
(SOA)
formation.
Yet,
the
understanding
of
OOM
components,
formation
mechanism,
impacts
still
limited,
especially
for
urbanized
regions
with
a
cocktail
anthropogenic
emissions.
Herein,
ambient
measurements
OOMs
were
conducted
at
regional
background
site
in
South
China
2018.
The
molecular
characteristics
revealed
dominant
nitrogen-containing
products,
influences
different
factors
on
composition
state
elucidated.
Positive
matrix
factorization
analysis
resolved
complex
species
to
featured
fingerprint
from
pathways.
A
new
method
was
developed
identify
key
functional
groups
OOMs,
which
successfully
classified
majority
into
carbonyls
(8%),
hydroperoxides
(7%),
nitrates
(17%),
peroxyl
(10%),
dinitrates
(13%),
aromatic
ring-retaining
(6%),
terpenes
(7%).
volatility
estimation
improved
based
their
identified
used
simulate
growth
process
contributed
by
condensation
those
low-volatile
OOMs.
results
demonstrate
predominant
role
contributing
sub-100
nm
particle
SOA
highlight
importance
products
multistep
oxidation.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(19), С. 8380 - 8392
Опубликована: Май 1, 2024
A
comprehensive
understanding
of
the
full
volatility
spectrum
organic
oxidation
products
from
benzene
series
precursors
is
important
to
quantify
air
quality
and
climate
effects
secondary
aerosol
(SOA)
new
particle
formation
(NPF).
However,
current
models
fail
capture
due
absence
reaction
pathways.
Here,
we
develop
a
novel
unified
model
framework,
integrated
two-dimensional
basis
set
(I2D-VBS),
simulate
by
simultaneously
representing
first-generational
oxidation,
multigenerational
aging,
autoxidation,
dimerization,
nitrate
formation,
etc.
The
successfully
reproduces
O/C
distributions
oxygenated
molecules
(OOMs)
as
well
concentrations
SOA
over
wide-ranging
experimental
conditions.
In
typical
urban
environments,
autoxidation
are
two
main
pathways
for
OOMs
with
similar
contributions,
but
contributes
more
low-volatility
products.
NOx
can
reduce
about
two-thirds
SOA,
most
extremely
compared
clean
conditions,
suppressing
dimerization
autoxidation.
I2D-VBS
facilitates
holistic
product
which
helps
fill
large
gap
in
predictions
NPF,
growth,
formation.