Abstract.
Atmospheric
aerosol
particles
play
a
key
role
in
air
pollution,
health,
and
climate.
Particles
from
biomass
burning
emissions
are
an
important
source
of
ambient
aerosols,
have
increased
over
the
past
few
decades,
projected
to
further
surge
future
as
result
climate
land
use
changes.
Largely
variety
organic
fuel
materials
combustion
types,
emitted
often
complex
mixtures
inorganic
materials,
with
soot,
ash,
charcoal
having
previously
been
identified
main
particle
types
being
emitted.
Despite
their
importance
for
climate,
ice
nucleation
activities
remain
insufficiently
understood,
particular
particles,
whose
activity
has
not
reported.
Here,
we
present
experiments
400
nm
size-selected
derived
pyrolysis
two
different
fuels,
namely
grass
wood
charcoal.
We
find
that
pyrolysis-derived
investigated
do
contribute
formation
via
immersion
freezing
mixed-phase
cloud
conditions.
However,
our
results
reveal
considerable
heterogeneous
both
at
cirrus
temperatures.
An
inspection
together
dynamic
vapor
sorption
measurements
indicates
proceeds
pore
condensation
freezing.
be
more
ice-active
than
attribute
this
enhanced
porosity
water
uptake
capacity
compared
In
support
results,
found
positive
correlation
chemical
composition,
specifically
presence
(inorganic)
mineral
components,
based
on
single-particle
mass
spectrometry
measurements.
Even
though
correlational
nature,
corroborate
recent
findings
minerals
could
largely
govern
aerosol–cloud
interactions
emissions.
Environmental Science Atmospheres,
Journal Year:
2023,
Volume and Issue:
3(12), P. 1693 - 1740
Published: Jan. 1, 2023
The
effects
of
aviation's
non-CO
2
emissions
on
climate
and
air
quality
are
complex
relatively
poorly
understood.
Mitigation
measures
need
to
be
very
carefully
considered
so
that
perverse
outcomes
do
not
result.
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(3), P. 2045 - 2058
Published: Feb. 16, 2024
Abstract.
The
radiative
characteristics
and
lifetimes
of
contrails
are
dependent
on
the
number
concentration
ice-forming
particles
in
engine
exhaust
plume.
Aircraft
gas
turbine
engines
produce
a
variety
particles,
yet
it
is
understood
that
non-volatile
black
carbon
aggregates
dominant
source
with
typical,
fossil-derived
jet
fuel.
However,
cleaner
combustion
technologies
adoption
alternative
fuels
(e.g.
hydrogen
or
synthetic
aviation
fuel),
particle
emissions
expected
to
decrease
even
be
eliminated.
Under
these
conditions,
contrail
properties
will
depend
upon
other
than
carbon.
Ultrafine
(<
100
nm)
lubrication
oil
droplets
constitute
significant
fraction
total
organic
particulate
matter
released
by
aircraft;
however,
their
ability
form
ice
crystals
has
hitherto
been
unexplored.
In
this
work,
we
experimentally
investigate
activation
freezing
behaviour
using
an
expansion
chamber,
assessing
potential
as
particles.
We
generate
geometric
mean
mobility
diameter
(100.9
±
0.6)
nm
show
activate
water
droplets,
which
subsequently
freeze
when
temperature
below
∼
235
K.
find
nucleation
should
considered
future
computational
studies
–
particularly
under
soot-poor
conditions
would
benefit
from
size
distribution
measurements
at
cruise
altitude.
Overall,
taking
steps
reduce
help
climate
impact
cirrus.
Journal of Geophysical Research Atmospheres,
Journal Year:
2022,
Volume and Issue:
127(22)
Published: Nov. 16, 2022
Abstract
Soot
particles
are
one
of
the
major
aerosol
components
(in
particle
number
concentration)
in
troposphere
and
can
impact
cirrus
formation.
Depending
on
their
physicochemical
properties,
soot
nucleate
ice
regime
via
pore
condensation
freezing
(PCF)
at
a
lower
saturation
threshold
than
that
homogeneous
solution
droplets.
undergoing
multiple
cloud
cycles
change
its
porosity
surface
wettability,
thus
modulating
PCF
ability.
In
this
study,
organic‐rich
‐lean
size‐selected
propane
flame
were
coated
with
different
thicknesses
sulfuric
acid
(H
2
SO
4
)
exposed
to
thermodynamic
conditions
under
228
K
relative
humidity
respect
water
104%
simulate
contrail
Ice‐activated
from
mimicked
sublimated
before
being
tested
for
nucleation
(IN)
T
≤
233
K.
Additionally,
size
mass
distribution
as
well
morphology
characterized.
The
results
demonstrate
increase
mesopore
availability
induced
by
cloud‐processing
plays
key
role
regulating
IN.
All
cloud‐processed
become
more
compacted,
however,
only
if
relevant
mesopores
generated,
compacted
exhibit
promoted
If
H
coating
and/or
enriched
organics
occupy
volume,
inhibition
is
observed
soot.
Notably,
thick
enhances
400
nm
organic‐lean
because
partially
engulfed
but
collapsed
soot‐core
may
have
new
produced
compaction.
Therefore,
abundance
evaluating
aged
IN
Abstract.
Aviation
soot
surrogates
processed
in
contrails
are
believed
to
become
potent
ice
nuclei
at
cirrus
temperature.
This
is
not
verified
for
real
aviation
soot,
that
can
have
vastly
different
physico-chemical
properties.
Here,
we
sampled
particles
from
in-use
commercial
aircraft
engines
and
quantified
the
effect
of
contrail
processing
on
their
nucleation
ability
T
<
228
K.
We
show
becomes
compacted
upon
but
this
does
change
contrast
other
types.
The
presence
H2SO4
condensed
pores,
highly
fused
nature
primary
arrangement
limit
volume
pores
generated
processing,
limiting
sites
nucleation.
Furthermore,
hypothesized
emitted
alternative
jet
fuel
would
also
be
poor
nucleating
if
emission
sizes
remain
small
(<
150
nm).
Atmospheric chemistry and physics,
Journal Year:
2023,
Volume and Issue:
23(2), P. 1285 - 1308
Published: Jan. 24, 2023
Abstract.
Atmospheric
aerosol
particles
play
a
key
role
in
air
pollution,
health,
and
climate.
Particles
from
biomass
burning
emissions
are
an
important
source
of
ambient
aerosols,
have
increased
over
the
past
few
decades,
projected
to
further
surge
future
as
result
climate
land
use
changes.
Largely
variety
organic
fuel
materials
combustion
types,
emitted
often
complex
mixtures
inorganic
materials,
with
soot,
ash,
charcoal
having
previously
been
identified
main
particle
types
being
emitted.
Despite
their
importance
for
climate,
ice
nucleation
activities
remain
insufficiently
understood,
particular
particles,
whose
activity
has
not
reported.
Here,
we
present
experiments
400
nm
size-selected
derived
pyrolysis
two
different
fuels,
namely
grass
wood
charcoal.
We
find
that
pyrolysis-derived
investigated
do
contribute
formation
via
immersion
freezing
mixed-phase
cloud
conditions.
However,
our
results
reveal
considerable
heterogeneous
both
at
cirrus
temperatures.
An
inspection
together
dynamic
vapor
sorption
measurements
indicates
proceeds
pore
condensation
freezing.
be
more
ice-active
than
attribute
this
enhanced
porosity
water
uptake
capacity
compared
In
support
results,
found
positive
correlation
chemical
composition,
specifically
presence
(inorganic)
mineral
components,
based
on
single-particle
mass
spectrometry
measurements.
Even
though
correlational
nature,
corroborate
recent
findings
minerals
could
largely
govern
aerosol–cloud
interactions
emissions.
Geophysical Research Letters,
Journal Year:
2024,
Volume and Issue:
51(7)
Published: April 4, 2024
Abstract
Organic‐lean
and
organic‐rich
size‐selected
soot
particles
were
exposed
to
a
varying
O
3
concentration,
progressively
decreasing
the
soot‐water
contact
angle
(
θ
)
study
its
impact
on
ice
nucleation
(IN).
The
IN
ability
of
fresh
‐aged
between
218
233
K
was
observed
while
monitoring
particle
mass
size
distributions.
properties
bulk
organic‐lean
samples
with
low
high
‐adsorption
characterized
for
,
chemical
composition,
functional
groups,
interaction
porosity.
By
retaining
porosity
aged
unaged
samples,
we
demonstrate
that
decrease
in
after
‐aging
enhances
via
pore
condensation
freezing.
Fresh
exhibits
suppressed
homogeneous
freezing,
but
it
freezes
within
uncertainty
freezing
threshold
solution
drops,
because
increased
hydrophilicity.
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(7), P. 4537 - 4567
Published: April 17, 2024
Abstract.
Ice-nucleating
particles
catalyze
ice
formation
in
clouds,
affecting
climate
through
radiative
forcing
from
aerosol–cloud
interactions.
Aviation
directly
emits
into
the
upper
troposphere
where
conditions
are
favorable.
Previous
studies
have
used
proxies
of
aviation
soot
to
estimate
their
nucleation
activity;
however,
investigations
with
commercial
aircraft
modern
in-use
engines
not
been
quantified.
In
this
work,
we
sample
at
ground
level
different
test
ability
temperatures
≤228
K
as
a
function
engine
thrust
and
particle
size.
Additionally,
were
catalytically
stripped
reveal
impact
mixing
state
on
ability.
Particle
physical
chemical
properties
further
characterized
related
properties.
The
results
show
that
nucleates
or
above
relative
humidity
required
for
homogeneous
freezing
solution
droplets
(RHhom).
We
attribute
mesopore
paucity
inhibiting
pore
condensation
sulfur
content
which
suppresses
freezing.
Only
large
aggregates
(400
nm)
emitted
under
30
%–100
%
subset
(2
out
10)
nucleate
via
For
those
specific
engines,
presence
hydrophilic
groups
facilitates
nucleation.
≥
100
(sea
thrust)
RHhom.
Overall,
our
suggest
will
contribute
natural
cirrus
can
be
models
update
impacts
soot–cirrus
clouds.
Abstract.
Ice
nucleating
particles
catalyse
ice
formation
in
clouds,
affecting
climate
through
radiative
forcing
from
aerosol-cloud
interactions.
Aviation
directly
emits
into
the
upper
troposphere
where
conditions
are
favourable.
Previous
studies
have
used
proxies
of
aviation
soot
to
estimate
their
nucleation
activity,
however
investigations
with
commercial
aircraft
modern
in-use
engine
not
been
quantified.
In
this
work,
we
sample
at
ground
level
different
engines
test
ability
temperatures
≤
228
K,
as
a
function
thrust
and
particle
size.
Additionally
were
catalytically
stripped
reveal
impact
mixing
state
on
ability.
Particle
physical
chemical
properties
further
characterised
related
properties.
The
results
show
that
nucleates
or
above
relative
humidity
required
for
homogeneous
freezing
solution
droplets
(RHhom).We
attribute
mesopore
paucity
inhibiting
pore
condensation
sulfur
content
which
suppresses
freezing.
Only
large
aggregates
(400
nm)
emitted
under
30–100
%
subset
(2/10)
nucleate
via
For
those
specific
engines,
presence
hydrophilic
groups
facilitates
nucleation.
≥100
(sea
thrust)
RHhom.
Overall
our
suggest
will
contribute
natural
cirrus
can
be
models
update
impacts
soot-cirrus
clouds.
