Deep Space Mapping of Saharan Dust Height

Dust
and
sand
lifted
from
the
Saharan
Desert
can
rise
up
in
into
the
Earth’s
atmosphere
and
travel
thousands
of
miles
across
the

Atlantic
Ocean,
reaching
as
far
away
as
the
United
States
and
the
Arctic.
Atmospheric
Saharan
debris
influences
ecosystems,
weather
systems,
and
even
air
quality.

Why
dust
height
matters

Understanding
how
high
Saharan
dust
ascends
in
the
atmosphere
is
important
for
assessing
its
impact
on
weather
forecasting
and

climate
modeling.
Dust
particles
in
the
air
can
scatter
and
absorb
sunlight,
influencing
atmospheric
temperature
profiles
and

cloud
formation.

It’s
not
just
the
geographic
extent
of
dust
in
the
atmosphere
that
is
important
to
understand
for
climate
modeling.
The
vertical
distribution
of
dust
in
the
atmosphere
affects
how
much
of
the
Sun’s
radiation
is
absorbed
or
reflected,
known
as
the
Earth’s
“radiative
balance”.

Limitations
of
active
sensors
in
measuring
atmospheric
Saharan
dust
height

Historical
remote
sensing
and
LiDAR
based
measurements
of
vertical
dust
height
have
their
limitations.
Active
sensors,
like

CALIPSO
(Cloud-Aerosol
Lidar
and
Infrared
Pathfinder
Satellite
Observation)
satellite
and
the International
Space
Station-based CATS
(Cloud-Aerosol
Transport
System) 
are
limited
in
their
geographic
scope
and
how
frequently
these
sensors
collect
data.
For
example,
researchers
from

NASA
noted
that
CALIPSO
was
only
able
to
measure
0.2%
of
the
atmosphere
in
2023.

Using
passive
remote
sensing
to
measure
atmospheric
dust

A
study
published
in
Geophysical
Research
Letters
looked
at
the
reliability
of
using
passive
remote
sensing
onboard
the
deep
space
satellite

DSCOVR
(Deep
Space
Climate
Observatory) .
Researchers
used
four
years
of
measurements
from
the
Earth
Polychromatic
Imaging
Camera
(EPIC)
to
calculate
the
average
monthly
heights
of
Saharan
dust
clouds.

Launched
in
2015,
DSCOVR
orbits
1
million
miles
from
Earth
at
the
Lagrange-1
point
(L1).
L1
is
the
point
between
the
Earth
and
the
Sun
where
the
gravitational
pull
of
these
two
planetary
bodies
cancels
out
(known
as
the
neutral
gravity
point).
From
this
position,
EPIC
is
able
to
remotely
sense
conditions
in
the
atmosphere
over
the

Atlantic
Ocean
every
1
to
2
hours.

Researchers
from
the
University
of
Iowa
extracted
vertical
dust
conditions
by
developing
an
algorithm
that
analyzed
data
collected
by
EPIC’s

oxygen
A
and
B
bands.
Over
a
four
year
period
(2015-2019)
average
vertical
atmospheric
dust
measurements
were
collected
for
two
separate
seasons:
the
wet
season
(May–October)
and
the
dry
season
(November–April).
The
study
found
that
during
the
wet
season,
solar
heating
creates
thermal
buoyancy
that
lifts
the
dust
higher
in
the
atmosphere
compared
with
the
dry
season.

Using
both
active
and
passive
sensing
to
measure
atmospheric
dust

By
contrast,
two
widely
used
models
(MERRA-2
and
NAAPS-RA)
do
not
capture
this
daily
pattern
in
dust
height.
These
results
suggest
that
EPIC’s
multiple
measurements
each
day
could
help
refine
atmospheric
models
so
they
can
better
represent
how
dust
moves
up
and
down
in
the
atmosphere
over
the
course
of
a
day.
Combining
active
and
passive
sensing
can
help
researchers
better
understand
how
dust
and
other
airborne
particles
vary
over
time.

References

Lu,
Z.,
Wang,
J.,
Chen,
X.,
Zeng,
J.,
Wang,
Y.,
Xu,
X.,
…
&
Xian,
P.
(2023).


First
mapping
of
monthly
and
diurnal
climatology
of
Saharan
dust
layer
height
over
the
Atlantic
Ocean
from
EPIC/DSCOVR
in
deep
space. Geophysical
Research
Letters, 50(5),
e2022GL102552.

Voiland, A.
(2025,
February
11). A
daily
boost
in
dust
height.
NASA
Earth
Observatory. 

Xu,
X.,
Wang,
J.,
Wang,
Y.,
Zeng,
J.,
Torres,
O.,
Yang,
Y.,
…
&
Miller,
S.
(2017).


Passive
remote
sensing
of
altitude
and
optical
depth
of
dust
plumes
using
the
oxygen
A
and
B
bands:
First
results
from
EPIC/DSCOVR
at
Lagrange‐1
point. Geophysical
Research
Letters, 44(14),
7544-7554.

Go to Source
Author: Caitlin Dempsey