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Monitoring the Arctic and Antarctic

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Satellites Used. Passive and active microwave sensors (SAR) SSM/I (launched in 1987) ... Polar Orbiting. Landsat. Nimbus. Differences in Monitoring Arctic and ... – PowerPoint PPT presentation

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Title: Monitoring the Arctic and Antarctic


1
Monitoring the Arctic and Antarctic
  • By Amanda Kamenitz

2
Introduction
  • Differences between Antarctic and Arctic
  • Satellites used to help monitor the ice content
    for both
  • What these tools are used for
  • Distinguishing between all of the different types
    of ice in both polar regions
  • Conclusions in the changes that occur over the
    years since satellite help

3
Arctic Ocean
  • Covered mostly by sea (2-3 meters thick)
  • High Albedo
  • Acts as a an energy sink for the Earth
  • The ocean span is 14 million km squared
  • Winter weather darkness, cold and stable
  • Summer Weather daylight, foggy, weak cyclones

4
Arctic contd.
  • Central surface covered by a perennial drifting
    polar ice
  • Ice pack surrounded by open seas over the summer
  • Landmass doubles the size in the winter

5
Antarctic
  • Antarctic Ice sheet makes up 98 of Antarctica
  • 14 million squared kilometers
  • 30 million cubic km of ice
  • 61 of Earths fresh water
  • East Antarctica rests on major land mass
  • West Antarctica can extend to 2,500 meters below
    sea leavel

6
Satellites Used
  • Passive and active microwave sensors (SAR)
  • SSM/I (launched in 1987)
  • EOS AMSR-E (launched in May 2002)
  • Sonars
  • Radiometers
  • AVHRR
  • Infrared Sensors
  • Polar Orbiting
  • Landsat
  • Nimbus

7
Differences in Monitoring Arctic and Antarctic
  • Microwave radiance differences
  • Ice tie points
  • First Year Ice type A
  • Multiyear Ice type B
  • For Antarctic distinguishing between A and B is
    lost
  • Emissivity differences
  • Snow cover on top of ice mimics the microwave
    signature of Multi year ice

8
SSM/I
  • Sea Ice concentration maps (1988-2001) derived
    from the sea brightness temperatures
  • Data extracted from ERS satellite imagery to find
    multiyear sea ice compounds
  • For January across these years revealed
    persistent coverage in central Arctic surrounded
    by fluctuating interannual cover
  • During 1988-2001 net January ice declined at a
    rate of -54.3 x 103 km2 per year.
  • Biggest decline in Chukchi and Beaufort Seas
  • In Fall 06 an increase in content of 105 km
    helped replenish the last 8 year decline
  • Arctic Oscillation also effects the ice content

9
SSM/I
10
AVHRR
  • Derives monthly monthly temperatures for the
    Arctic
  • Surface temperatures at latitudes higher then 60
    (1981-2003) increased on average ½ degree Celsius
    per decade
  • Warming trends vary with season also (Winters in
    Eurasia produce more cooling)
  • Net warming shows that there a few more days of
    warming rather then cooling
  • Limited area can underestimate the warming in
    certain areas

11
AMSR-E (Advanced Microwave Scanning Radiometer
Observing System)
  • High spatial resolution (5-50 km), twice the
    resolution then any before
  • Wide range of frequencies
  • More accurate for measuring sea ice content
  • Six different frequencies (horizontal and
    vertical polarizations)
  • Sea ice content observed at National Snow and Ice
    Data Center

12
AMSRE (Aqua Satellite)
  • Maximum sea ice of 2008 on March 9th
  • False color in image derived from 6.25 km 89 GHz
    brightness
  • Sea ice extent derived from AMSRE 12.5 km sea ice
    concentration

13
Landsat and Nimbus
  • Optical passive systems
  • Measure radiation from Earths surface and
    atmosphere
  • Nimbus-7 (launched 1978)
  • Swath width 185 km
  • Brightness temperature (Kelvin)
  • Spatial resolution 25 km
  • Landsat-7 (images acquired March 2003)
  • Variety of sea ice conditions and concentrations
  • Measures radiation in visible and near IR
  • Images of Bering and Chukchi Seas
  • Converts Spectral Radiance to planetary
    reflectance by ?p?L?d2ESun ?cos?s

14
Landsat-7
15
Sea Ice Concentration with Landsat-7
16
Nimbus 7
17
Distinguishing the Arctic
  • Albedo
  • Atmospheric effects
  • Spectral reflectance and Snow density (.38-1.20
    micrometers)

18
Contd.
  • Optical Microwave Remote Sensing
  • Emissive mode inadequate for detecting glaciers

19
NASAs studies on Ice Concentration for Arctic
and Antarctic
  • 30 Year span of satellite imagery
  • N. Hemisphere Arctic melting
  • S. Hemisphere Antarctic increasing over the past
    few years (dramatic decrease from 1973-1977)
  • Recently Arctic losing ice at a faster rate
  • Comparing Arctic for the past 2 decades to past 3
    decades theres a 20 faster decreasing rate
  • 1972-2002 Arctic has decreased the size of
    Arizona (300,000 square km of loss per decade)
  • The Antarctic increase is not enough to make up
    for previous losses
  • 1972-2002 Antarctic decreasing 150,000 square km
    per decade
  • Recent Antarctic increase may be due to long term
    atmospheric oscillations bringing stronger
    westerly winds and cooler temperatures

20
Arctic Ice change (NOAAs Climactic Data Center)
21
References
  • http//svs.gsfc.nasa.gov
  • http//earthobservatory.nasa.gov/Newsroom/NasaNews
    /2003/2003111016173.html Arctic and Antarctic Sea
    Ice Marching to Different Drivers
  • http//www.iarc.uaf.edu/highlights/2004/satellite_
    monitoring_arctic_ice_cap.php View from Above
    Satellite Monitoring o the Arctic Ice Cap
  • http//ghrc.msfc.nasa.gov5721/sensor_documents/ss
    mi_sensor.html Special Sensor Microwave Imager
    (SSM/I) Sensor Document
  • http//ieeexplore.ieee.org/iel5/36/36139/01717697.
    pdf?tpisnumberarnumber1717697 Assessment of
    EOS Aqua AMSR-E Arctic Sea Ice Concentrations
    Using Landsat-7 and Airborne Microwave Imagery.
  • http//scitation.aip.org/journals/doc/PHTOAD-ft/vo
    l_57/iss_8/38_1.shtml Satellite Observed Changes
    in the Arctic. Physics Today
  • http//nsidc.org/data/docs/daac/nasateam/index.htm
    l NASA Team Sea Ice Algorithm. Donald J.
    Cavalieri
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