Abstract.
A
new
retrieval
algorithm
to
obtain
vertical
profiles
of
the
aerosol
extinction
coefficient
from
measurements
scattered
solar
light
in
limb
viewing
geometry
made
by
OMPS-LP
instrument
is
presented.
The
method
employs
normalization
radiances
irradiance
contrast
a
measurement
at
an
upper
tangent
height,
which
used
most
other
published
limb-scatter
retrievals.
main
advantage
this
approach
nearly
complete
elimination
dependence
results
on
prior
profile
retrieval.
This
makes
well
suitable
analyze
observation
scenes
with
highly
elevated
plumes
as
occurred
after
Hunga
Tonga-Hunga
Ha'apai
volcanic
eruption
January
2022.
were
compared
independent
data
SAGE
III/ISS
and
OSIRIS.
In
general,
agreement
within
25
%
between
different
products
was
observed
although
larger
differences
seen
very
strong
eruptions
wildfires.
product
investigate
evolution
plume
eruption.
Journal of Geophysical Research Atmospheres,
Journal Year:
2023,
Volume and Issue:
128(22)
Published: Nov. 22, 2023
Abstract
The
Hunga
Tonga‐Hunga
Ha'apai
(HTHH)
volcanic
eruption
in
January
2022
injected
unprecedented
amounts
of
water
vapor
(H
2
O)
and
a
moderate
amount
the
aerosol
precursor
sulfur
dioxide
(SO
)
into
Southern
Hemisphere
(SH)
tropical
stratosphere.
H
O
perturbations
have
persisted
during
early
2023
dispersed
throughout
atmosphere.
Observations
show
large‐scale
SH
stratospheric
cooling,
equatorward
shift
Antarctic
polar
vortex
slowing
Brewer‐Dobson
circulation.
Satellite
observations
substantial
ozone
reductions
over
winter
midlatitudes
that
coincide
with
largest
circulation
anomalies.
Chemistry‐climate
model
simulations
forced
by
realistic
HTHH
inputs
SO
qualitatively
reproduce
observed
evolution
plumes
first
year,
exhibits
changes
effects
similar
to
behavior.
agreement
demonstrates
are
caused
influences.
Geophysical Research Letters,
Journal Year:
2023,
Volume and Issue:
50(14)
Published: July 25, 2023
Abstract
We
use
Aura
Microwave
Limb
Sounder
(MLS)
trace
gas
measurements
to
investigate
whether
water
vapor
(H
2
O)
injected
into
the
stratosphere
by
Hunga
Tonga‐Hunga
Ha'apai
(HTHH)
eruption
affected
2022
Antarctic
stratospheric
vortex.
Other
MLS‐measured
long‐lived
species
are
used
distinguish
high
HTHH
H
O
from
that
descending
in
vortex
upper‐stratospheric
peak.
reached
southern
latitudes
June–July
but
was
effectively
excluded
strong
transport
barrier
at
its
edge.
MLS
O,
nitric
acid,
chlorine
species,
and
ozone
within
polar
were
near
average;
large,
strong,
long‐lived,
not
exceptionally
so.
There
is
thus
no
clear
evidence
of
influence
on
or
composition.
Substantial
impacts
vortices
expected
succeeding
years
since
has
spread
globally.
Geophysical Research Letters,
Journal Year:
2023,
Volume and Issue:
50(18)
Published: Sept. 26, 2023
Abstract
On
15
January
2022,
the
Hunga
Tonga‐Hunga
Ha'apai
(HT)
eruption
injected
SO
2
and
water
into
middle
stratosphere.
The
is
rapidly
converted
to
sulfate
aerosols.
aerosol
vapor
anomalies
have
persisted
in
Southern
Hemisphere
throughout
2022.
anomaly
increases
net
downward
IR
radiative
flux
whereas
layer
reduces
direct
solar
forcing.
reduction
larger
than
increased
flux.
Thus,
tropospheric
forcing
will
be
negative.
changes
peak
July
August
diminish
thereafter.
Scaling
observed
cooling
after
1991
Pinatubo
eruption,
HT
would
cool
2022
Hemisphere's
average
surface
temperatures
by
less
0.037°C.
Journal of Geophysical Research Atmospheres,
Journal Year:
2023,
Volume and Issue:
128(16)
Published: Aug. 2, 2023
Abstract
The
January
2022
eruption
of
Hunga
Tonga‐Hunga
Ha'apai
(HT‐HH)
caused
the
largest
enhancement
in
stratospheric
aerosol
loading
decades
and
produced
an
unprecedented
water
vapor,
leading
to
strong
cooling
that
turn
induced
changes
large‐scale
circulation.
Here
we
use
satellite
measurements
gas‐phase
constituents
together
with
extinction
investigate
extent
which
thick
aerosol,
excess
moisture,
enabled
heterogeneous
chemical
processing.
In
southern
tropics,
unambiguous
signatures
substantial
chlorine
nitrogen
repartitioning
appear
over
a
broad
vertical
domain
almost
immediately
after
eruption,
depletion
N
2
O
5
,
NO
x
HCl
accompanied
by
HNO
3
ClO,
ClONO
.
After
initially
rising
steeply,
ClO
plateau,
maintaining
fairly
constant
abundances
for
several
months.
These
patterns
are
consistent
saturation
hydrolysis,
suggesting
this
reaction
is
primary
mechanism
observed
composition
changes.
midlatitudes
subtropics
show
similar
but
weaker
enhancements
those
regions,
however,
effects
anomalous
transport
dominate
evolution
HCl,
obscuring
signs
Perturbations
species
considerably
than
measured
midlatitude
stratosphere
2020
following
Australian
New
Year's
fires.
moderate
HT‐HH‐induced
reactive
seen
throughout
middle
low‐latitude
stratosphere,
far
smaller
typical
winter
polar
vortices,
do
not
lead
appreciable
ozone
loss;
rather,
extrapolar
lower‐stratospheric
remains
primarily
controlled
dynamical
processes.
Proceedings of the National Academy of Sciences,
Journal Year:
2023,
Volume and Issue:
120(46)
Published: Oct. 30, 2023
The
Hunga
Tonga–Hunga
Ha’apai
(HT-HH)
volcanic
eruptions
on
January
13
and
15,
2022,
produced
a
plume
with
the
highest
signal
in
stratospheric
aerosol
optical
depth
observed
since
eruption
of
Mt.
Pinatubo
1991.
Suites
balloon-borne
instruments
series
launches
from
Réunion
Island
intercepted
HT-HH
between
7
10
d
eruptions,
yielding
observations
number
size
distribution
sulfur
dioxide
(SO
2
)
water
vapor
(H
O)
concentrations.
measurements
reveal
an
unexpected
abundance
large
particles
plume,
constrain
total
injected
to
approximately
0.2
Tg,
provide
information
altitude
injection,
indicate
that
formation
sulfuric
acid
was
complete
within
3
wk.
Large
H
O
enhancements
contributed
as
much
~30%
ambient
surface
area
likely
accelerated
SO
oxidation
rates
three
times
faster
than
under
normal
conditions.
Geophysical Research Letters,
Journal Year:
2024,
Volume and Issue:
51(7)
Published: April 1, 2024
Abstract
Following
the
Hunga
Tonga–Hunga
Ha'apai
(HTHH)
eruption
in
January
2022,
stratospheric
ozone
depletion
was
observed
at
Southern
Hemisphere
mid‐latitudes
and
over
Antarctica
during
2022
austral
wintertime
springtime,
respectively.
The
injected
sulfur
dioxide
unprecedented
amounts
of
water
vapor
into
stratosphere.
This
work
examines
chemistry
contribution
volcanic
materials
to
using
chemistry‐climate
model
simulations
with
nudged
meteorology.
Simulated
nitrogen
oxide
(NO
x
=
NO
+
2
)
anomalies
show
good
agreement
satellite
observations.
We
find
that
yields
up
4%
destruction
near
∼70
hPa
August
20%
∼80
October.
Most
is
attributed
internal
variability
dynamical
changes
forced
by
eruption.
Both
modeling
observations
a
significant
reduction
associated
HTHH
aerosol
plume,
indicating
enhanced
dinitrogen
pentoxide
hydrolysis
on
sulfate
aerosol.
Abstract.
A
new
retrieval
algorithm
to
obtain
vertical
profiles
of
the
aerosol
extinction
coefficient
from
measurements
scattered
solar
light
in
limb
viewing
geometry
made
by
OMPS-LP
instrument
is
presented.
The
method
employs
normalization
radiances
irradiance
contrast
a
measurement
at
an
upper
tangent
height,
which
used
most
other
published
limb-scatter
retrievals.
main
advantage
this
approach
nearly
complete
elimination
dependence
results
on
prior
profile
retrieval.
This
makes
well
suitable
analyze
observation
scenes
with
highly
elevated
plumes
as
occurred
after
Hunga
Tonga-Hunga
Ha'apai
volcanic
eruption
January
2022.
were
compared
independent
data
SAGE
III/ISS
and
OSIRIS.
In
general,
agreement
within
25
%
between
different
products
was
observed
although
larger
differences
seen
very
strong
eruptions
wildfires.
product
investigate
evolution
plume
eruption.
Journal of Geophysical Research Atmospheres,
Journal Year:
2024,
Volume and Issue:
129(14)
Published: July 24, 2024
Abstract
We
calculate
the
climate
forcing
for
2
ys
after
15
January
2022,
Hunga
Tonga‐Hunga
Ha'apai
(Hunga)
eruption.
use
satellite
observations
of
stratospheric
aerosols,
trace
gases
and
temperatures
to
compute
tropopause
radiative
flux
changes
relative
climatology.
Overall,
net
downward
decreased
compared
The
water
vapor
anomaly
initially
increases
infrared
flux,
but
this
diminishes
as
disperses.
aerosols
cause
a
solar
reduction
that
dominates
change
over
most
yrs
period.
induced
temperature
produce
decrease
in
long‐wave
flux.
ozone
short‐wave
creating
small
sub‐tropical
increase
total
from
mid‐2022
2023.
By
end
2023,
have
disappeared.
There
is
some
disagreement
measured
aerosol
optical
depth
(SAOD)
which
we
view
measure
uncertainty;
however,
SAOD
uncertainty
does
not
alter
our
conclusion
that,
overall,
dominate
changes.
Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(1), P. 535 - 553
Published: Jan. 16, 2025
Abstract.
The
Global
Space-based
Stratospheric
Aerosol
Climatology
(GloSSAC)
is
essential
for
understanding
and
modeling
the
climatic
impacts
of
stratospheric
aerosols.
It
relies
primarily
on
data
from
Gas
Experiment
(SAGE)
satellite
series,
supplemented
by
Optical
Spectrograph
Infrared
Imaging
System
(OSIRIS)
Cloud-Aerosol
Lidar
Pathfinder
Satellite
Observations
(CALIPSO).
GloSSAC
currently
provides
aerosol
extinction
coefficients
optical
depths
at
525
1020
nm.
With
CALIPSO
decommissioned
OSIRIS
nearing
end
its
operational
life,
SAGE
III/ISS
(International
Space
Station)
will
soon
become
sole
source
GloSSAC,
but
it
only
be
available
as
long
ISS
operational,
until
around
2030.
Therefore,
incorporating
other
measurements,
such
those
Ozone
Mapping
Profiler
Suite
Limb
(OMPS-LP),
critical.
OMPS-LP
has
provided
continuous
coefficient
measurements
since
2012
with
a
retrieval
algorithm
developed
NASA,
i.e.,
OMPS(NASA).
However,
OMPS(NASA)
been
shown
to
overestimate
coefficients,
particularly
after
2022
Hunga
Tonga
eruption,
compared
tomographic
OMPS
University
Saskatchewan
(OMPS(SASK))
III/ISS.
Our
analysis
shows
that
indeed
exhibits
consistently
high
bias
(>50
%)
following
large
volcanic
eruptions
pyrocumulonimbus
plumes
intense
wildfires,
while
OMPS(SASK)
reasonable
agreement
between
40°
S
N.
This
overestimation
leads
an
effective
radiative
forcing
(ERF)
associated
model-simulated
global
surface
temperature
response
factor
about
2.
Atmospheric measurement techniques,
Journal Year:
2024,
Volume and Issue:
17(22), P. 6677 - 6695
Published: Nov. 25, 2024
Abstract.
A
new
retrieval
approach
for
obtaining
vertical
profiles
of
the
aerosol
extinction
coefficient
from
measurements
scattered
solar
light
in
limb-viewing
geometry
made
by
Ozone
Mapper
and
Profiler
Suite
Limb
(OMPS-LP)
instrument
is
presented.
In
contrast
to
many
other
published
limb-scatter
retrievals,
our
algorithm
does
not
employ
normalization
a
limb
measurement
at
an
upper
tangent
height.
Instead,
measured
radiances
are
normalized
irradiance.
The
main
advantage
this
almost
complete
elimination
dependence
results
on
prior
profile
used
retrieval.
This
makes
better
suited
analysis
observation
scenes
with
highly
elevated
plumes,
such
as
those
that
occurred
after
Hunga
Tonga–Hunga
Ha′apai
volcanic
eruption
January
2022.
were
compared
coefficients
retrieved
Stratospheric
Aerosol
Gas
Experiment
III
International
Space
Station
(SAGE
III/ISS)
Optical
Spectrograph
InfraRed
Imaging
System
(OSIRIS).
general,
agreement
within
25
%
between
different
data
products
was
observed
18–23
km
altitude
range,
although
larger
differences
seen
very
strong
eruptions
wildfires.
comparison
OSIRIS,
high
southern
latitudes
(above
60°
S).
product
investigate
evolution
plume
eruption.
