Authorea (Authorea),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Oct. 17, 2023
Multispectral
mapping
data
from
the
Compact
Reconnaissance
Imaging
Spectrometer
for
Mars
(CRISM)
provide
a
unique
opportunity
to
characterize
south
polar
ice
deposits
at
higher
spectral
sampling,
spatial
resolution,
or
spatiotemporal
coverage
than
previous
work.
This
new
perspective
can
help
constrain
nature
and
distribution
of
different
mixtures
CO
ice,
HO
dust
that
influence
formation,
evolution,
preservation
climate
records.
We
processed
1103
CRISM
observations
spanning
southern
summer
six
Years
(MY)
through
combination
k
-means
clustering
random
forest
classification.
Using
set
12
endmembers
directly
tied
work
with
high-resolution
targeted
data,
we
made
series
temporally
restricted
mosaics
showing
surface
variation
over
time.
The
show
effects
MY
28
storm
on
removal
seasonal
cap
year
reveal
how
this
process
differed
years
followed.
A
mosaic
residual
surfaces
displays
broad
agreement
compositional
maps
while
resolving
details
in
ice-rich
material
around
periphery
bright
cap.
By
composition
varies
across
swath
region
though
time,
endmember
classified
produced
critical
context
future
studies
dynamic
processes
shape
deposits.
Icarus,
Journal Year:
2023,
Volume and Issue:
419, P. 115801 - 115801
Published: Sept. 19, 2023
Carbon
dioxide
is
Mars'
most
active
volatile.
The
seasonal
and
diurnal
processes
of
when
where
it
condenses
sublimates
are
determined
by
energy
balance
between
the
atmosphere
surface
ice
in
vapor
pressure
equilibrium
climate.
current
obliquity
ensures
that
polar
caps
stable
locations
for
condensation.
eccentricity
orbit
major
driver
differences
behavior
CO2
northern
vs
southern
hemisphere.
In
particular,
seasons
perihelion
aphelion,
addition
to
large
elevation
difference
poles,
dominate
ways
transpire
two
hemispheres.
We
summarize
discuss
unprecedented
observations
these
have
been
collected
Mars
Reconnaissance
Orbiter
over
last
8.5
Years.
longer
fall
winter
allows
more
time
accumulate
densify
Northern
coincides
with
dust
storm
season,
thus
north
deposits
expected
contain
a
greater
concentration
relation
H2O
ices.
With
less
densification
contaminants
layer
likely
weaker
than
layer.
Journal of Geophysical Research Planets,
Journal Year:
2024,
Volume and Issue:
129(3)
Published: March 1, 2024
Abstract
The
north
and
south
polar
layered
deposits
(PLD)
on
Mars
are
composed
of
stacks
ice
dust,
but
the
SPLD
is
approximately
twice
as
bright
NPLD
in
20‐MHz
radar
echoes.
We
use
Shallow
Radar
(SHARAD)
data
∼4‐MHz
bands
centered
17.5
MHz
(“
L
”)
22.5
H
to
determine
whether
reflectivity
variations
due
scattering
effects
related
closely
spaced,
near‐surface
dielectric
layering.
mapped
ratio
surface
echo
power
at
two
frequencies
(
/
)
for
both
PLDs.
has
large
areas
where
differ,
consistent
with
destructive
interference
band
within
uppermost
∼20
m.
dominated
by
∼
(unity),
except
isolated
regions
near
residual
CO
2
cap
Australe
Lingula.
can
be
partly
explained
structure,
match
locations
numerous
reflecting
interfaces,
may
contain
few
such
reflectors.
There
no
obvious
connection
between
morphology,
distribution
non‐unity
resembles
extent
a
widespread,
recent
accumulated
package
(WRAP)
poles.
spatial
association
WRAP
indicated
suggests
that
NPLD—and
SPLD—are
characterized
shallow
layer(s)
thickness/separation
potentially
deposited
past
tens
kyr
emerged
from
last
obliquity‐driven
age.
The Planetary Science Journal,
Journal Year:
2023,
Volume and Issue:
4(12), P. 232 - 232
Published: Dec. 1, 2023
Abstract
Martian
slope
streaks
are
large
surface
features
with
lower
albedo
than
their
surroundings
that
one
of
the
few
active
geologic
processes
occurring
on
Mars
today.
We
investigated
streaks’
spectral
properties
using
images
from
Compact
Reconnaissance
Imaging
Spectrometer
for
(CRISM)
at
nine
sites,
including
three
sites
observations
over
multiple
years
to
enable
time-series
analysis.
For
each
individual
streak
within
image,
we
determined
average
spectra
and
immediately
adjacent
account
changes
in
geology
across
a
CRISM
image
or
slopes
containing
streaks.
find
trend
where
visible
continuum
(0.4–0.6
μ
m)
is
strongly
negative
darkest
streaks,
increases
as
fade,
consistent
all
same
site.
do
not
absorption
1.4
1.9
m
associated
hydration.
In
some
see
evidence
Fe-bearing
minerals,
but
these
signatures
also
found
streak-free
directly
adjacent,
suggesting
have
similar
mineralogy
surroundings.
The
most
fine
dust
component
support
dry
flow
mechanism
whereby
formed
by
trigger
removal
particular
locations,
slowly
fading
resettles
surface.
Journal of Geophysical Research Planets,
Journal Year:
2023,
Volume and Issue:
128(11)
Published: Nov. 1, 2023
Abstract
Multispectral
mapping
data
from
the
Compact
Reconnaissance
Imaging
Spectrometer
for
Mars
(CRISM)
provide
a
unique
opportunity
to
characterize
south
polar
ice
deposits
at
higher
spectral
sampling,
spatial
resolution,
or
spatiotemporal
coverage
than
previous
work.
This
new
perspective
can
help
constrain
nature
and
distribution
of
different
mixtures
CO
2
ice,
H
O
dust
that
influence
formation,
evolution,
preservation
climate
records.
We
processed
1,103
CRISM
observations
spanning
southern
summer
six
Years
(MYs)
through
combination
k
‐means
clustering
random
forest
classification.
Using
set
12
endmembers
directly
tied
work
with
high‐resolution
targeted
data,
we
made
series
temporally
restricted
mosaics
showing
surface
variation
over
time.
The
show
effects
MY
28
storm
on
removal
seasonal
cap
year
reveal
how
this
process
differed
years
followed.
A
mosaic
residual
surfaces
displays
broad
agreement
compositional
maps
while
resolving
details
in
ice‐rich
material
around
periphery
bright
cap.
By
composition
varies
across
swath
region
time,
endmember
classified
produced
critical
context
future
studies
dynamic
processes
shape
deposits.
Authorea (Authorea),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Aug. 12, 2023
Multispectral
mapping
data
from
the
Compact
Reconnaissance
Imaging
Spectrometer
for
Mars
(CRISM)
provide
a
unique
opportunity
to
characterize
south
polar
ice
deposits
at
higher
spectral
sampling,
spatial
resolution,
or
spatiotemporal
coverage
than
previous
work.
This
new
perspective
can
help
constrain
nature
and
distribution
of
different
mixtures
CO2
ice,
H2O
dust
that
influence
formation,
evolution,
preservation
climate
records.
We
processed
1103
CRISM
observations
spanning
southern
summer
six
Years
(MY)
through
combination
k-means
clustering
random
forest
classification.
Using
set
12
endmembers
directly
tied
work
with
high-resolution
targeted
data,
we
made
series
temporally
restricted
mosaics
showing
surface
variation
over
time.
The
show
effects
MY
28
storm
on
removal
seasonal
cap
year
details
how
this
process
differed
years
followed.
A
mosaic
residual
surfaces
displays
broad
agreement
compositional
maps
while
resolving
in
ice-rich
material
around
periphery
bright
cap.
By
composition
varies
across
swath
region
though
time,
endmember
classified
produced
critical
context
future
studies
dynamic
processes
shape
deposits.
