Abstract.
Recent
studies
hypothesize
that
emissions
from
fires
reaching
the
stratosphere
can
provide
aerosols
and
aerosol
precursors
initiate
stratospheric
ozone
loss
lead
to
radiative
heating
of
cooling
surface.
Air
troposphere
enters
primarily
over
tropical
western
Pacific
(TWP)
during
boreal
winter.
We
report
observations
in
TWP
persistent,
ubiquitous
continental
pollution
tropopause
layer
(TTL)
lower
(LS)
Airborne
Tropical
TRopopause
EXperiment
(ATTREX)
campaign
February–March
2014.
found
concentrations
carbon
monoxide
(CO)
enhanced
up
65
%
background
levels
deep
tropics
(5°
S–15°
N,
16
–17
km).
Correlations
CO
with
hydrocarbon
halocarbon
species
indicated
a
biomass
burning
source,
largest
enhancements
warmer,
clear
air.
Satellite
did
not
detect
thin
layers
observed
by
aircraft,
but
indicate
Africa,
Indonesia,
western/central
as
geographical
hot
spots
for
TTL.
Backward
trajectories
identified
convective
encounters
these
areas
dominant
sources
polluted
air
TWP.
Africa
Indonesia
contributed
about
60
excess
CO,
transported
two
four
weeks.
Our
study
confirms
TTL
is
affected
distant
rapidly
reach
LS
principal
source
region
entering
stratosphere,
supporting
view
regions
could
impact
temperatures.
Photochemical & Photobiological Sciences,
Год журнала:
2023,
Номер
22(5), С. 937 - 989
Опубликована: Апрель 21, 2023
This
assessment
provides
a
comprehensive
update
of
the
effects
changes
in
stratospheric
ozone
and
other
factors
(aerosols,
surface
reflectivity,
solar
activity,
climate)
on
intensity
ultraviolet
(UV)
radiation
at
Earth's
surface.
The
is
performed
context
Montreal
Protocol
Substances
that
Deplete
Ozone
Layer
its
Amendments
Adjustments.
Changes
UV
low-
mid-latitudes
(0-60°)
during
last
25
years
have
generally
been
small
(e.g.,
typically
less
than
4%
per
decade,
increasing
some
sites
decreasing
others)
were
mostly
driven
by
cloud
cover
atmospheric
aerosol
content,
caused
partly
climate
change
measures
to
control
tropospheric
pollution.
Without
Protocol,
erythemal
(sunburning)
irradiance
northern
southern
latitudes
50°
would
increased
10-20%
between
1996
2020.
For
exceeding
50°,
Index
(UVI)
surged
25%
(year-round
tip
South
America)
more
100%
(South
Pole
spring).
Variability
Antarctica
was
very
large
four
years.
In
spring
2019,
minimum
historical
(1991-2018)
range
Pole,
while
near
record-high
values
observed
2020,
which
up
80%
above
mean.
Arctic,
highest
irradiances
record
measured
March
April
example
monthly
average
UVI
over
site
Canadian
Arctic
70%
higher
(2005-2019)
average,
often
this
mean
three
standard
deviations.
Under
presumption
all
countries
will
adhere
future
concentrations
remain
constant,
(30-60°)
projected
decrease
2015
2090
2-5%
north
4-6%
south
due
recovering
ozone.
for
tropics
are
≤
3%.
However,
industrial
regions
currently
affected
air
pollution,
increase
as
reduce
pollutants
gradually
restore
intensities
those
cleaner
atmosphere.
Since
most
substances
controlled
also
greenhouse
gases,
phase-out
these
may
avoided
warming
0.5-1.0
°C
mid-latitude
continents,
1.0
Arctic;
however,
uncertainty
calculations
large.
We
assess
climate,
focusing
poleward
shift
zones,
discuss
role
Antarctic
hole
2019
devastating
"Black
Summer"
fires
Australia.
Additional
topics
include
advances
measuring
modeling
radiation;
methods
determining
personal
exposure;
effect
management
(stratospheric
injections)
relevant
plants;
possible
revisions
vitamin
D
action
spectrum,
describes
wavelength
dependence
synthesis
previtamin
Photochemical & Photobiological Sciences,
Год журнала:
2023,
Номер
22(5), С. 1049 - 1091
Опубликована: Фев. 1, 2023
Terrestrial
organisms
and
ecosystems
are
being
exposed
to
new
rapidly
changing
combinations
of
solar
UV
radiation
other
environmental
factors
because
ongoing
changes
in
stratospheric
ozone
climate.
In
this
Quadrennial
Assessment,
we
examine
the
interactive
effects
ozone,
climate
on
terrestrial
biogeochemical
cycles
context
Montreal
Protocol.
We
specifically
assess
organisms,
agriculture
food
supply,
biodiversity,
ecosystem
services
feedbacks
system.
Emphasis
is
placed
role
extreme
events
altering
exposure
potential
biodiversity.
also
address
responses
plants
increased
temporal
variability
radiation,
change
(e.g.
drought,
temperature)
crops,
driving
breakdown
organic
matter
from
dead
plant
material
(i.e.
litter)
biocides
(pesticides
herbicides).
Our
assessment
indicates
that
interact
various
ways
affect
structure
function
ecosystems,
by
protecting
layer,
Protocol
continues
play
a
vital
maintaining
healthy,
diverse
land
sustain
life
Earth.
Furthermore,
its
Kigali
Amendment
mitigating
some
negative
consequences
limiting
emissions
greenhouse
gases
carbon
sequestration
vegetation
pool.
Communications Earth & Environment,
Год журнала:
2022,
Номер
3(1)
Опубликована: Окт. 17, 2022
Abstract
High-intensity
wildland
fires
can
produce
extreme
flaming
and
smoke
emissions
that
develop
into
a
fire-cloud
chimney,
reaching
the
upper
troposphere
or
lower
stratosphere.
Termed
pyrocumulonimbus,
these
storms
are
both
conventional
counterintuitive.
They
have
been
observed
to
lightning,
hail,
downdraft
wind
hazards,
tornadoes
as
expected
with
severe
convective
storms,
but
counterintuitively,
they
not
associated
significant
precipitation.
Pyrocumulonimbus
noticed
outside
wildfire
expert
circles
following
Australia’s
Black
Summer
in
2019/20,
since
repeatedly
made
headlines
United
States.
However,
much
is
unknown
about
their
behavior,
energetics,
history,
impact
on
Earth/atmosphere
system.
We
address
several
questions
science
challenges
related
unknowns.
Our
worldwide
record
of
pyrocumulonimbus
events
from
2013
2021
shows
phenomenon
neither
new
nor
rare.
Despite
high
occurrences
2019
2021,
data
do
support
identification
trend.
Future
studies
require
an
expansive
occurrence
globally
regionally,
historically
continuously
forward
time.
Atmospheric chemistry and physics,
Год журнала:
2022,
Номер
22(14), С. 9299 - 9311
Опубликована: Июль 20, 2022
Abstract.
As
a
consequence
of
extreme
heat
and
drought,
record-breaking
wildfires
developed
ravaged
south-eastern
Australia
during
the
fire
season
2019–2020.
The
strength
reached
its
paroxysmal
phase
at
turn
year
During
this
phase,
pyrocumulonimbus
clouds
(pyroCb)
injected
biomass
burning
aerosols
gases
into
upper
troposphere
lower
stratosphere
(UTLS).
UTLS
aerosol
layer
was
massively
perturbed
by
these
fires,
with
extinction
increased
factor
3
in
visible
spectral
range
Southern
Hemisphere,
respect
to
background
atmosphere,
stratospheric
optical
depth
reaching
values
as
large
0.015
February
2020.
Using
best
available
description
event
observations,
we
estimate
radiative
forcing
(RF)
such
perturbations
Hemispheric
layer.
We
use
offline
transfer
modelling
driven
observed
information
perturbation
variability
obtained
from
limb
satellite
measurements.
Based
on
hypotheses
absorptivity
angular
scattering
properties
layer,
regional
(at
three
latitude
bands
Hemisphere)
clear-sky
TOA
(top-of-atmosphere)
RF
is
found
varying
small
positive
relatively
negative
(up
−2.0
W
m−2),
surface
be
consistently
−4.5
m−2).
argue
that
are
unlikely
for
event,
if
ageing/mixing
plume
mirrored
evolution
properties.
Our
area-weighted
global-equivalent
-0.35±0.21
(TOA
RF)
-0.94±0.26
m−2
(surface
RF),
thus
strongest
documented
comparable
magnitude
volcanic
eruptions
post-Pinatubo
era.
surplus
surface,
TOA,
due
absorption
within
has
contributed
generation
ascending
smoke
vortices
stratosphere.
Highly
reflective
underlying
surfaces,
like
clouds,
can
nevertheless
swap
RF,
global
average
high
+1.0
assuming
highly
absorbing
particles.
Geophysical Research Letters,
Год журнала:
2022,
Номер
49(10)
Опубликована: Май 21, 2022
Abstract
The
latter
months
of
2020
and
2021
were
marked
by
two
the
largest
Antarctic
ozone
holes
on
record.
That
such
large
occurred
despite
ongoing
recovery
raises
questions
about
their
origins
climate
impacts.
Here
we
provide
novel
evidence
that
supports
hypothesis
influenced
distinct
extraordinary
events:
Australian
wildfires
early
eruption
La
Soufriere
in
2021.
We
further
reveal
both
associated
with
widespread
changes
Southern
Hemisphere
are
consistent
established
impacts
depletion,
including
a
strengthening
polar
stratospheric
vortex,
enhanced
surface
westerlies
over
Ocean,
temperature
Antarctica
Australia.
results
thus
suggestive
injections
wildfire
smoke
volcanic
emissions
into
stratosphere
can
lead
to
hemispheric‐scale
climate.
Science,
Год журнала:
2023,
Номер
379(6634), С. 815 - 820
Опубликована: Фев. 24, 2023
Pyrocumulonimbus
(pyroCb)
are
wildfire-generated
convective
clouds
that
can
inject
smoke
directly
into
the
stratosphere.
PyroCb
have
been
tracked
for
years,
yet
their
apparent
rarity
and
episodic
nature
lead
to
highly
uncertain
climate
impacts.
In
situ
measurements
of
pyroCb
reveal
its
distinctive
exceptionally
stable
aerosol
properties
define
long-term
influence
activity
on
stratospheric
budget.
Analysis
13
years
airborne
observations
shows
responsible
10
25%
black
carbon
organic
aerosols
in
"present-day"
lower
stratosphere,
with
similar
impacts
both
North
South
Hemispheres.
These
results
suggest
that,
should
increase
frequency
and/or
magnitude
future
climates,
they
could
generate
dominant
trends
aerosol.