why do we have landsat?

Why Do We Have Landsat?

•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?

NASA’s Earth Science Research Questions

Landsat Science Themes

Monitoring Ecosystem Changes

• Climate Dynamics

• Quantifying Water and Energy Budgets

• Quantifying Earth’s Carbon Cycle

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:

Although Climate Change is a global phenomenon…

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?

… the effects of climate change on ecosystems are local and heterogeneous

- treeline/ecotone changes- invasive species- desertification- coral reef declines, etc.



Forest fragmentation in Amazon basin

Coastal Marsh Loss in the Eastern U.S.

Loss of Mesopotamian Wetlands

Mapping extent and morphology of coral reefs

Mapping Spotted Owl Habitat, Oregon

1973-76

2000

Gradual changes require long-term, repeat satellite coverage

Loss of wetlands in Mesopotamia (dark red areas) since 1973 from Landsat. Courtesy Hassan Partow, UNEP


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

Example: Eastern Hemlock Decline

D. Royle and R. Lathrop, Rutgers University

Highlands

Piedmont

Ridge & Valley

Ecosystem disturbance and invasive species may be harbingers of climate change


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

Courtesy U.S. Forest Service

Cerro Grande Fire, New Mexico

April 14, 2000 Before Fire

May 9, 2000 During Fire

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.

June 17, 2000 After Fire


• Monitoring Ecosystem Changes




MODIS, AVHRR SeaWiFS

Global Climate Models

GlobalSurfaceProperties

GlobalClimate andWeather

RegionalLand-cover and surface properties

Landsat

Mesoscale Models

RegionalClimateAnalyses

Landsat and Climate Modeling

Example: Climate and Land-Cover Change

Pre-1900 Vegetation1990’s Land Cover from Landsat

Do changes in landscape structure affect regional climate?

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

•Monitoring Ecosystem Changes




Quantifying Water and Energy Budgets

• By 2025, 48% of global population will live in “water stressed” basins (<1700 m3/pers/yr)

1973

1987

2000

ARAL SEAWill future water supplies meet human needs?

Courtesy WRIWater flux into the Aral Sea is being diverted for human use

Most mountain glaciers worldwide have been retreating

Franz Josef Glacier, New Zealand

Mountain Glacier Dynamics

What changes are occurring in the mass of the Earth's ice cover?

D. Hall, NASA GSFC

Pasterze Glacier,

Austria 06-Sept-1999


Antarctic Monitoring

R. Bindschadler, NASA GSFC

Landsat Archive


LDCM Science Themes

• Monitoring Ecosystem Changes




Together with other Earth Observing Satellite instruments, Landsat plays a critical role in NASA’s studies of Earth:

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?”

Atmospheric CO2

250

275

300

325

350

375

1000 1200 1400 1600 1800 2000

year( AD)

pp

mQuantifying Earth’s Carbon Cycle

Carbon Sources and Sinks

source: WHRC

8

6

4

2

0

-2

-4

-6

1850 1870 1890 1910 1930 1950 1970 1990-8

So

urc

eS

inks

Emissions from Fossil FuelsNet release from land-use change

Unidentified sinkOceanic uptakeAtmospheric accumulation

1.6 +/- 1.0

5.5 +/- 0.5

1.9

2.0 +/- 0.8

3.2 +/- 0.2

Pg

C /

yr Reforestation

Fire Supression

Woody Encroachment

CO2, N Fertilization

Climate

Human-induced Carbon Flux since 1850: where has all the carbon gone?

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

1970 1980 1990 2000

MSS (79 m, 4 band)

TM (30/120 m, 7 band)

ETM+ (15/30/60 m, 8 band)

2010

LDCM Sensor (15/30/90 m, 9 band

Landsat-2

Landsat-3

Landsat-4

Landsat-5

Landsat-6

LDCM

Government operations

Commercial operations

Landsat-1 (ERTS)

Landsat-7

Landsat – 30 Years of Earth Observations

Landsat-7 Global Acquisitions

The first truly global archive

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

Extending the Legacy of Global Extending the Legacy of Global Land ObservationsLand Observations

Landsat Data Continuity Mission

National Aeronautics and Space Administrationhttp://www.nasa.gov

why do we have landsat?

Documents