Transcript Document

Why Do We Have Landsat?
NASA’s 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 humaninduced 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 NASA’s studies of Earth.
A cornerstone of NASA’s Global Change Research:
Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earth’s 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
Forest fragmentation in Amazon basin
Mapping Spotted Owl Habitat, Oregon
Coastal Marsh Loss in the Eastern U.S.
Loss of Mesopotamian Wetlands
Mapping extent and morphology of
coral reefs
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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
1973-76
2000
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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 bands
of burned
areas
A ratio
of Landsat
4 and
7 is also
and for verification of coarse scale
burn-scar
usedoperational
to create burn
severity maps which
mapping.
are key in the post-fire rapid assessment
process led by the Burn Area Emergency
Response (BAER) Team.
April 14, 2000
Before Fire
Cerro Grande
Fire, New Mexico
May 9, 2000
During Fire
June 17, 2000
After Fire
Courtesy U.S. Forest Service
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• Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earth’s Carbon Cycle
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Landsat and Climate Modeling
MODIS, AVHRR
SeaWiFS
Landsat
Regional
Land-cover and
surface
properties
Global
Surface
Properties
Global Climate
Models
Regional
Climate
Analyses
Mesoscale
Models
Global
Climate and
Weather
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Example: Climate and Land-Cover Change
Do changes in landscape structure affect regional climate?
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Pre-1900 Vegetation
1990’s Land Cover from Landsat
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•Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earth’s Carbon Cycle
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Quantifying Water and Energy Budgets
Will future water supplies meet
human needs?
ARAL SEA
1973
• By 2025, 48% of global population will
live in “water stressed” basins (<1700
m3/pers/yr)
1987
2000
Courtesy WRI
Water flux into the Aral Sea
is being diverted for human use
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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 NASA’s studies of Earth:
• Monitoring Ecosystem Changes
• Climate Dynamics
• Quantifying Water and Energy Budgets
• Quantifying Earth’s Carbon Cycle
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Quantifying Earth’s 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?”
375
Atmospheric CO2
ppm
350
325
300
275
250
1000
1200
1400
1600
1800
2000
year( AD)
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6
Emissions from Fossil Fuels
Net release from land-use change
Pg C / yr
Unidentified sink
4
2
0
Oceanic uptake
Atmospheric accumulation
5.5 +/- 0.5
Reforestation
Fire Supression
1.6 +/- 1.0
Woody Encroachment
1.9
-2
2.0 +/- 0.8
-4
3.2 +/- 0.2
Sinks
8
Source
Carbon Sources and Sinks
CO2, N Fertilization
Climate
-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
Landsat-1 (ERTS)
Landsat-2
Landsat-3
Landsat-4
Landsat-5
Landsat-6
MSS (79 m, 4 band)
Landsat-7
TM (30/120 m, 7 band)
ETM+ (15/30/60 m, 8 band)
LDCM Sensor (15/30/90 m, 9 band
1970
1980
LDCM
1990
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.gsfc.nasa.gov
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National Aeronautics and Space Administration
http://www.nasa.gov
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