Transcript Global Change: Remote sensing

Global Change: Remote sensing
full-resolution image
Global Change: Remote sensing
Imagery: small scale (coarse) resolution – large area
Visit September Sea Ice Concentrations for an animation of September sea ice
concentrations 1979 -2010.
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
Reflected:
Emitted:
Environmental Remote Sensing
1. Visible wavelengths
2. Near/mid Infra-Red
3. Thermal infra-red (Heat)
4. Microwave radar (cloud-free)
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 radiation
Most 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 band
b. Grayscale ->
c. Pseudocolour
High-res imagery: large-scale small area
http://www.abc.net.au/news/infographics/qld-floods/beforeafter.htm
Low res: large area
http://www.ssmi.com/sst/sst_data_daily.html?sat=tmi_amsre
Urban growth: Landsat (since 1972)
Deforestation
2003: Cranbrook Hill – the green University
03
06
2006 Cranbrook Hill – the red-green university
remote sensing change applications
Lake 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 1999
Includes 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, 2010
MODIS 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
Glacier Change in Area (km²)
(~ 1985 – 2005)
-285 km²
-824 km²
-78.8 km²
- 167 km²
-89.1 km²
- 453 km²
-235 km²
- 814 km²
-342 km²
- 3.4 km²
T. Bolch, B.Menounos, R. Wheate
Glacier Retreat Rates (% a-1)
(~ 1985 – 2005)
-0.44 ± 0.15
-0.35 ± 0.13
-0.79 ± 0.15
Alberta: -1.27 ± 0.17
-1.20 ± 0.16
BC: -0.54 ± 0.15
-0.88 ± 0.16
-1.21 ± 0.23
-0.67 ± 0.15
-0.61 ± 0.18
-0.72 ± 0.14
-1.11 ± 0.24
3 - Glacier Changes
Whole Inventory: -0.55 ± 0.16
T. Bolch, B.Menounos, R. Wheate
Glacier Retreat Rates (% a-1)
(1985 – 2000; 2000-2005)
-0.69 ± 0.23
-0.27 ± 0.19
-1.03 ± 0.70
-0.44 ± 0.53
-0.47 ± 0.33
-0.49 ± 0.26
-0.79 ± 0.81
-0.66 ± 0.23 -1.21 ± 0.96
-0.92 ± 0.74
T. Bolch, B.Menounos, R. Wheate
1992
2006
(Homathko River Park)
3D Visualisation of past and future change
created from air photos, images and mapping
Glaciers 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/