Why Do We Have Landsat

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Why Do We Have Landsat?
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NASAs Earth Science Research Questions

• How is the global Earth system changing?
• What are the primary causes of change in the
  Earth System?
• How does the Earth system respond to natural and
  human-induced changes?
• What are the consequences of change in the Earth
  systems for human civilization?
• How can we predict future changes in the Earth
  system?

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Landsat Science Themes
Together with other Earth Observing Satellite
instruments, Landsat plays a critical role in
NASAs studies of Earth.
A cornerstone of NASAs Global Change Research

• Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earths Carbon Cycle

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Monitoring Ecosystem Changes

• NASA Earth Science Questions with Respect to
  Ecosystems
• How are global ecosystems changing?
• How do ecosystems respond to and affect global
  environmental change and the carbon cycle?

Although Climate Change is a global phenomenon
the effects of climate change on ecosystems are
local and heterogeneous - treeline/ecotone
changes - invasive species - desertification -
coral reef declines, etc.
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Monitoring Ecosystem Changes
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Monitoring Ecosystem Changes
Gradual changes require long-term, repeat
satellite coverage

• Landsat data are used to
• Precisely assess the area affected
• Separate human from natural causes
• Bridge the gap between field observations and
  global monitoring

Loss of wetlands in Mesopotamia (dark red areas)
since 1973 from Landsat. Courtesy Hassan Partow,
UNEP
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Monitoring Ecosystem Changes
Ecosystem disturbance and invasive species may be
harbingers of climate change
Example Eastern Hemlock Decline
Ridge Valley
Highlands
Piedmont
D. Royle and R. Lathrop, Rutgers University
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Monitoring Ecosystem Changes

• Landsat is well suited to providing detailed maps
  of burned areas and for verification of coarse
  scale operational burn-scar mapping.

A ratio of Landsat bands 4 and 7 is also used to
create burn severity maps which are key in the
post-fire rapid assessment process led by the
Burn Area Emergency Response (BAER) Team.
Cerro Grande Fire, New Mexico
Courtesy U.S. Forest Service
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• Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earths Carbon Cycle

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Landsat and Climate Modeling
Global Climate and Weather
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Example Climate and Land-Cover Change
Do changes in landscape structure affect regional
climate?
Pre-1900 Vegetation
1990s Land Cover from Landsat
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• Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earths Carbon Cycle

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Quantifying Water and Energy Budgets
Will future water supplies meet human needs?
1973
ARAL SEA

• By 2025, 48 of global population will live in
  water stressed basins (lt1700 m3/pers/yr)

1987
2000
Water flux into the Aral Sea is being diverted
for human use
Courtesy WRI
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Quantifying Water and Energy Budgets
What changes are occurring in the mass of the
Earth's ice cover?
Mountain Glacier Dynamics
Franz Josef Glacier, New Zealand
Most mountain glaciers worldwide have been
retreating
Pasterze Glacier, Austria 06-Sept-1999
D. Hall, NASA GSFC
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Quantifying Water and Energy Budgets
Antarctic Monitoring
Landsat Archive
R. Bindschadler, NASA GSFC
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LDCM Science Themes
Together with other Earth Observing Satellite
instruments, Landsat plays a critical role in
NASAs studies of Earth

• Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earths Carbon Cycle

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Quantifying Earths Carbon Cycle

• Increasing atmospheric CO2 levels are correlated
  with increasing global temperatures
• How well can cycling of carbon through the earth
  system be modeled, and how reliable are
  predictions of future atmospheric concentrations
  of carbon dioxide and methane by these models?

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Carbon Sources and Sinks
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Emissions from Fossil Fuels Net release from
land-use change Unidentified sink Oceanic
uptake Atmospheric accumulation
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Source
4
2
0
-2
Sinks
-4
-6
-8
1850
1870
1890
1910
1930
1950
1970
1990
Human-induced Carbon Flux since 1850 where has
all the carbon gone?
source WHRC
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The Landsat Mission

• Over 30-year years of global land cover data
• Resolution shows human activities
• Key information for climate, ecosystems,
  biogeochemical cycles, and hydrology studies

EPA-USGS NALC Land-cover Dataset
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Landsat 30 Years of Earth Observations
MSS (79 m, 4 band)
TM (30/120 m, 7 band)
ETM (15/30/60 m, 8 band)
LDCM
LDCM Sensor (15/30/90 m, 9 band
1990
1970
1980
2000
2010
Commercial operations
Government operations
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Landsat-7 Global Acquisitions
The first truly global archive
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Landsat Data Continuity Mission
Extending the Legacy of Global Land Observations
The Landsat Data Continuity Mission (aka LDCM)
will continue the legacy of the Landsat program.
Launch dates are years away, and the request for
proposals for the instrument is to be released
soon. For more information on the next satellite
in the Landsat series, please visit http//ldcm.gs
fc.nasa.gov
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