On the drivers of ice nucleating particle diurnal variability in Eastern Mediterranean clouds
npj Climate and Atmospheric Science,
Journal Year:
2025,
Volume and Issue:
8(1)
Published: May 5, 2025
Abstract
We
report
the
drivers
of
spatiotemporal
variability
ice
nucleating
particles
(INPs)
for
mixed-phase
orographic
clouds
(~−25
°C)
in
Eastern
Mediterranean.
In
planetary
boundary
layer,
pronounced
INP
diurnal
periodicity
is
observed,
which
mainly
driven
by
biological
(and
to
a
lesser
extent,
dust)
but
not
aerosols
from
biomass
burning.
The
comparison
size-resolved
and
fluorescence-discriminated
aerosol
particle
properties
with
INPs
reveals
primary
role
fluorescent
bioaerosol.
presence
Saharan
dust
increases
during
nighttime
more
than
daytime,
because
lower
layer
height
decreases
contribution
(including
bioaerosols)
layer.
absent
free
troposphere,
although
levels
are
availability
bioaerosol
particles.
Given
effective
nucleation
ability
bioaerosols
subsequent
effects
multiplication
at
warm
temperatures,
lack
such
cycles
models
points
important
overlooked
cloud
formation
precipitation
mountainous
regions.
Language: Английский
Sources and Variability of Greenhouse Gases over Greece
Atmosphere,
Journal Year:
2024,
Volume and Issue:
15(11), P. 1288 - 1288
Published: Oct. 27, 2024
This
study
provides
an
overview
of
the
atmospheric
drivers
climate
change
over
Greece
(Eastern
Mediterranean),
focusing
on
greenhouse
gases
(GHG:
carbon
dioxide,
CO2;
methane,
CH4;
etc.).
CO2
in
is
mostly
produced
by
energy
production,
followed
transport,
construction,
and
industry.
Waste
management
largest
anthropogenic
source
accounting
for
47%
total
CH4
emissions,
surpassing
emissions
from
agricultural
sector
2017,
while
accounts
remaining
10.5%.
In
situ
simultaneous
observations
GHG
concentrations
conducted
at
three
sites
with
different
topologies
(urban
background;
Athens,
regional
Finokalia
free
troposphere;
Helmos)
during
last
5
years
(2019–2023)
showed
increasing
trends
order
2.2
ppm·yr−1
~15
ppb·yr−1
CH4,
respectively,
line
global
trends.
These
were
found
both
ground-based
satellite-based
remote-sensing
observations.
Finally,
lockdown
period
due
to
COVID-19
pandemic,
a
58%
reduction
levels
was
observed
urban
background
site
Athens
after
subtracting
Finokalia,
respective
only
15%,
highlighting
differences
emission
sources.
Language: Английский
Drivers of droplet formation in east Mediterranean orographic clouds
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(17), P. 9827 - 9842
Published: Sept. 5, 2024
Abstract.
The
purpose
of
this
study
is
to
understand
the
drivers
cloud
droplet
formation
in
orographic
clouds.
We
used
a
combination
modeling,
situ,
and
remote
sensing
measurements
at
high-altitude
Helmos
Hellenic
Atmospheric
Aerosol
Climate
Change
((HAC)2)
station,
which
located
top
Mt.
(1314
m
above
sea
level),
Greece,
during
Cloud–AerosoL
InteractionS
Background
TropOsphere
(CALISHTO)
campaign
fall
2021
(https://calishto.panacea-ri.gr/,
last
access:
1
August
2024)
examine
origins
aerosols
(i.e.,
local
aerosol
from
planetary
boundary
layer
(PBL)
or
long-range-transported
free-tropospheric
(FTL)
contributing
condensation
nuclei
(CCN)),
their
characteristics
(hygroscopicity,
size
distribution,
mixing
state),
vertical
velocity
distributions
resulting
supersaturations.
found
that
PBL
were
considerably
different
FTL
use
particle
number
equivalent
mass
concentration
black
carbon
(eBC)
order
determine
when
(HAC)2
was
within
based
on
time
series
height
PBL.
During
events
we
sample
mixture
interstitial
residues,
characterize
using
new
approach
utilizes
situ
periods
purely
interstitial.
From
dataset
properties
(size
distribution
hygroscopicity)
pre-cloud,
activated,
aerosol.
hygroscopicity
activated
be
higher
than
pre-cloud
A
closure
studies
with
parameterization
shows
(Nd)
supersaturation
can
predicted
25
%
observations
correspond
conditions.
analysis
characteristic
each
population
indicates
clouds
aerosol-limited
formed
air
masses
–
hence
driven
by
variations,
while
tend
velocity-limited
variations
are
fluctuations
velocity.
Given
dynamics
do
not
vary
significantly
between
masses,
variation
type
mostly
responsible
for
these
shifts
microphysical
state
sensitivity
With
insights,
droplets
such
infer
either
CCN
spectra
(when
FTL)
PBL).
In
conclusion,
show
coordinated
measurement
properties,
together
novel
approaches
presented
here,
allows
determination
variations.
Language: Английский
Biological and dust aerosols as sources of ice-nucleating particles in the eastern Mediterranean: source apportionment, atmospheric processing and parameterization
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(17), P. 9939 - 9974
Published: Sept. 9, 2024
Abstract.
Aerosol–cloud
interactions
in
mixed-phase
clouds
(MPCs)
are
one
of
the
most
uncertain
drivers
hydrological
cycle
and
climate
change.
A
synergy
situ,
remote-sensing
modelling
experiments
were
used
to
determine
source
ice-nucleating
particles
(INPs)
for
MPCs
at
Mount
Helmos
eastern
Mediterranean.
The
influences
boundary
layer
turbulence,
vertical
aerosol
distributions
meteorological
conditions
also
examined.
When
observation
site
is
free
troposphere
(FT),
approximately
1
×106
serve
as
INPs
around
−25
°C.
INP
abundance
spans
3
orders
magnitude
increases
following
order:
marine
aerosols;
continental
and,
finally,
dust
plumes.
Biological
important
observed
aerosols,
whereas
they
play
a
secondary,
although
important,
role
during
Saharan
events.
Air
masses
planetary
(PBL)
show
both
enriched
concentrations
higher
proportion
total
particles,
compared
with
cases
FT.
presence
precipitation/clouds
enriches
FT
but
decreases
PBL.
Additionally,
new
parameterizations
developed
that
incorporate
ratio
fluorescent-to-nonfluorescent
or
coarse-to-fine
predict
>90
%
within
an
uncertainty
range
factor
10;
these
exhibit
better
performance
than
current
widely
allow
ice
formation
models
respond
variations
biological
particles.
improved
can
help
MPC
simulations
regions
various
sources
different
prevailing
sources.
Language: Английский