global change: remote sensing full-resolution image
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Global Change: Remote sensing
full-resolution image
Global Change: Remote sensing
Visit September Sea Ice Concentrations for an animation of September sea ice concentrations 1979 -2010.
Imagery: small scale (coarse) resolution – large area
Changes in snowmelt, Greenland
High resolution: Jakobshavn Glacier http://earthobservatory.nasa.gov/IOTD/view.php?id=44625
2010 tied with 2005 as the warmest year since global records began in 1880
Kilimanjaro: 1993 and 2000
“ice predicted to disappear by 2010”
new estimate: 2030
Higher temperatures
or lower moisture
(presipitation) ?
Introduction
Remotely sensed satellite imagery is suitable for monitoring changes, with regular orbits
Repeat period = 1- 20 days ...subject to cloud cover and scale
There are few satellite 'photos' - they are images, captured along scan paths. e.g. Earthnow (this webpage app needs Java)
Early earth monitoring satellites were launched by NASA, but now many from other countries (and corporations). Types vary according to:
1. Electromagnetic spectrum wavelengths
Environmental Remote Sensing 1. Visible wavelengths 2. Near/mid Infra-Red 3. Thermal infra-red (Heat) 4. Microwave radar (cloud-
free)
Reflected:Emitted:
2. Sensor types: resolution (pixel size
) <1 metre to 10 kilometre
Low resolution 1km -10km (national) 5000 x 5000km www.goes.noaa.gov
Medium res. 100 -500 m (regional) 500 x 500km MODIS
High resolution 10-100 m http://landsat.gsfc.nasa.gov/ 200km (1972->80m) (1982->30m) SPOT 60 x 60km (1986-10m) http://gallery.spotimage.com/
Very high 1 - 10 metres (Local) 60 x 60km Ikonos Quickbird Tsunami 2004 Geoeye
3. Types of sensors – active or passive mode
Passive – capturing reflected solar or emitted terrestrial radiationMost of the images so far
Active – using sensor generated energy
RADAR (microwave)
LiDAR (visible / near IR)
Sensors: Remote Sensing Instruments
Full list: http://visibleearth.nasa.gov/view_set.php?sensorName=all
New satellite sensors: http://members.home.nl/wim.h.bakker
There are 3 types of image displays:
a. RGB composite
= 3 ‘bands’
left - visible wavelengths
Right – using IR
Single bandb. Grayscale ->
c. Pseudocolour
http://www.abc.net.au/news/infographics/qld-floods/beforeafter.htm
High-res imagery: large-scale small area
Low res: large areahttp://www.ssmi.com/sst/sst_data_daily.html?sat=tmi_amsre
Urban growth: Landsat (since 1972)
Deforestation
032003: Cranbrook Hill – the green University
062006 Cranbrook Hill – the red-green university
remote sensing change applicationsLake loss: Aral Sea
Earthshots: satellite images of environmental change
Urban expansion: Las Vegas
Agricultural expansion- Elburz, Iran Environmental accident: Chernobyl Deforestation: Rondonia (Brazil)
desertification - Aral Sea
TERRA satellite 1999Includes two sensors: MODIS and ASTER
MODIS- bands and applications (250 / 500 / 1000m)http://modis.gsfc.nasa.gov/about/specifications.php
MODIS- sensing for global change research: http://glcf.umiacs.umd.edu/library/pdf/ieeetgrs36_p1228.pdf
MODIS Rapid Response System Global Fire Maps
http://rapidfire.sci.gsfc.nasa.gov
August 22, 2010MODIS image
Castle Glacier, near McBride
Central Coast Mountains, Landsat September 2003
Central Coast Mountains, Landsat August 2006
Landsat image, Mt. Robson Park, 1990 (all Landsat archive -> online in 2009)
Successive glacier extents for Mt. Robson glaciers 1900-2005
-342 km²
-824 km²-78.8 km²
-89.1 km²
-235 km²
- 3.4 km²
- 814 km²
- 453 km²
-285 km²
- 167 km²
Glacier Change in Area (km²)
(~ 1985 – 2005)
T. Bolch, B.Menounos, R. Wheate
-0.72 ± 0.14
-0.35 ± 0.13-0.79 ± 0.15
-0.88 ± 0.16
-0.67 ± 0.15
-1.11 ± 0.24
-0.61 ± 0.18
-1.21 ± 0.23
-0.44 ± 0.15
-1.20 ± 0.16
Glacier Retreat Rates (% a-1)
(~ 1985 – 2005)
T. Bolch, B.Menounos, R. Wheate
BC: -0.54 ± 0.15
Alberta: -1.27 ± 0.17
Whole Inventory: -0.55 ± 0.163 - Glacier Changes
Glacier Retreat Rates (% a-1)
(1985 – 2000; 2000-2005)
-0.66 ± 0.23-0.49 ± 0.26
-0.27 ± 0.19-0.69 ± 0.23
-0.47 ± 0.33
T. Bolch, B.Menounos, R. Wheate
-1.03 ± 0.70
-0.44 ± 0.53
-1.21 ± 0.96
-0.92 ± 0.74-0.79 ± 0.81
19922006
(Homathko River Park)
3D Visualisation of past and future change
created from air photos, images and mappingGlaciers and vegetation Glacier National Park (Montana)
MARS720: Is there global change on Mars?http://www.msss.com/mars_images/moc/CO2_Science_rel/
DEM resolution
z = 30cm!
Useful websites
NASA weekly images http://earthobservatory.nasa.gov/Newsroom/
Earth image of the day: http://earthobservatory.nasa.gov/IOTD/view.php
Visible Earth: http://visibleearth.nasa.gov/