Image Credits

Introduction: Detecting Change - Understanding Change

Lake Chad in Africa in 1972 and then later in October 2001, showing the changes in water area and cover conditions that have occurred between these two dates
Satellite images
US Geological Survey, USA
URL: Lake Chad, West Africa, 1963, 1973, 1987, 1997, 2007
Last access: 09.06.2009
View of the entrance to the Arsenal in Venice, painted in 1732 by Canaletto
Painting
The image is a Wikimedia Commons file created by User: Dacxjo under the terms of the GNU Free Documentation Licence, Version 1.2.
URL: http://commons.wikimedia.org/wiki/File:View_of_the_entrance_
to_the_Arsenal_by_Canaletto,_1732.jpg
Last access: 10.06.2009
View of the entrance to the Arsenal in Venice, photograph taken in August 2006
Photography
The image is a Wikimedia Commons file created by User: MarkusMark under the terms of the GNU Free Documentation Licence, Version 1.2.
URL: http://commons.wikimedia.org/wiki/File:38VeneziaArsenale.jpg
Last access: 10.06.2009

1. What is a time series and why are they important?

Monthly values for atmospheric carbon dioxide concentration, measured at Mauna Loa, Hawaii
Graph
NOAA Mauna Loa Observatory, Hawaii, USA
URL: http://www.mlo.noaa.gov/programs/esrl/co2/co2.html
Last access: 09.06.2009
Tidal elevations of the sealevel for Dover - blue dots
Graph
Proudman Oceanographic Laboratory, UK
URL: http://www.pol.ac.uk/ntslf/sadata_tgi_ntslf_v2.php?code=Dover
Last access: 09.06.2009
The price of US light crude oil, rising between 7 January and 8 May 2008
Graph
BBC, UK
URL: http://news.bbc.co.uk/1/hi/business/7385061.stm
Last access: 09.06.2009
Annual-mean Central England Temperature...
Graph
Department for Environment, Food and Rural Affairs, UK
URL: http://www.ecn.ac.uk/iccuk//indicators/1.htm, Author: M Hulme
Last access: 09.06.2009
One-month tidal record of the sealevel for Dover
Graph
Proudman Oceanographic Laboratory, UK
URL: http://www.pol.ac.uk/ntslf/sadata_tgi_ntslf_v2.php?code=Dover
Last access: 09.06.2009
Two-days tidal record of the sealevel for Dover
Graph
Proudman Oceanographic Laboratory, UK
URL: http://www.pol.ac.uk/ntslf/sadata_tgi_ntslf_v2.php?code=Dover
Last access: 09.06.2009
Seven-days tidal record of the sealevel for Dover
Graph
Proudman Oceanographic Laboratory, UK
URL: http://www.pol.ac.uk/ntslf/sadata_tgi_ntslf_v2.php?code=Dover
Last access: 09.06.2009

2. Working with Time Series

The coastline in the southern North Sea along the coasts of Denmark, Germany and The Netherlands...
Photography and graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
URL: http://www.watt.icbm.de/16809.html
Last access: 30.06.2009
Time series of air (red curve) and seawater temperature (blue curve), salinity and water level measured during eight days in June 2007.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Time series as above, but for eight days in December 2007..
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Time series of air (red curve) and seawater temperature (blue curve) and seawater salinity measured between October 2002 and March 2009.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Monthly averaged time series data of air (red curve) and seawater temperature (blue curve) and salinity measured between October 2002 and March 2009.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Near-surface water temperature averaged over the entire North Sea in October, between 1968 and 2006.
Graph
Bundesamt für Seeschiffahrt und Hydrographie, Hamburg, Germany
URL: http://www.bsh.de/de/Das_BSH/Presse/Pressearchiv/Pressemitteilungen2006/39-2006.jsp
Last access: 03.07.2009
Averaged water temperature (blue points) near Spiekeroog island in October, between 2002 and 2008.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Water temperatures in July
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
...and a selection of fit lines
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Same diagram as above but in x/y coordinates.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Centroid P(x,y) of the data points, with x=4.08 and y=19.01.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Distance to fit line, version 1.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Distance to fit line, version 2.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Data points in x/y coordinates
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Water temperatures in July.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Data points, their centroid P(x,y) and linear best-fit line f(x)=ax+b.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Seawater temperature near Spiekeroog in July 2003 - 3008, mean July temperature...
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Question: Correlated or uncorrelated
Graph
The image is a Wikimedia Commons file created by User: Jtneill under the terms of the GNU Free Documentation Licence, Version 1.2.
URL: http://en.wikipedia.org/wiki/File:Correlation_examples.png
Last access: 10.07.2009
The data shown is the monthly atmospheric carbon dioxide density in parts per million by volume (ppmv) for Mauna Loa, 1959 − 2005
Graph, plotted by Keith Raymond McCloy, Aarhus University, Denmark using Mauna Loa Laboratory data
NOAA Mauna Loa Laboratory, USA
URL: http://www.esrl.noaa.gov/gmd/ccgg/trends/
Last access: 09.06.2009
The trend in atmospheric carbon dioxide at Mauna Loa from 1959 to 2005 according to the parabolic fit to the data
Graph
Keith Raymond McCloy, Aarhus University, Denmark
By subtracting the trend estimated using the parabolic fit, from the actual data, we get the residuals
Graph
Keith Raymond McCloy, Aarhus University, Denmark
The seasonal cycle
Graph
Keith Raymond McCloy, Aarhus University, Denmark
The residuals left over after removing the seasonality
Graph
Keith Raymond McCloy, Aarhus University, Denmark
The frequency graph for our data. The central value can be considered to have a frequency of zero and an infinitely long wavelength; it is like a constant term
Graph
Keith Raymond McCloy, Aarhus University, Denmark
A closer look at the frequency graph
Graph
Keith Raymond McCloy, Aarhus University, Denmark
The frequencies selected to be removed
Graph
Keith Raymond McCloy, Aarhus University, Denmark
The residuals that remain after the residuals dataset above are removed from the dataset used as the source to this analysis. This dataset still contains some structure
Graph
Keith Raymond McCloy, Aarhus University, Denmark

5. Ice in the Arctic

September ice extent 1979 - 2008
Graph
National Snow and Ice Data Center, USA
URL: http://nsidc.org/news/press/20081002_seaice_pressrelease.html
Last access: 29.06.2009
Arctic sea ice extent September 2008
Plot
National Snow and Ice Data Center, USA
URL: http://nsidc.org/news/press/20081002_seaice_pressrelease.html
Last access: 29.06.2009
Ice albedo
Graphic
Don Perovich, U.S. Army Cold Regions Research and Engineering Laboratory.
URL: Ice albedo
Last access: 11.06.2009
Arctic fox
Photography
National Snow and Ice Data Center, USA
URL: http://nsidc.org/seaice/environment/mammals.html
Last access: 29.06.2009
Narwhals
Photography
National Institute of Standards and Technology, USA
URL: http://www.nist.gov/public_affairs/images/05MSEL012_narwhals_breachHR.jpg
Last access: 29.06.2009
Frazil ice
Photography
National Snow and Ice Data Center, USA
URL: http://nsidc.org/cgi-bin/words/letter.pl?F
Last access: 11.06.2009
Rafted ice
Photography
Don Perovich, U.S. Army Cold Regions Research and Engineering Laboratory.
URL: http://www.crrel.usace.army.mil/sid/personnel/perovichweb/photogallery/
photo00008999/real.htm
Last access: 29.06.2009
Pancake ice
Photography
Don Perovich, U.S. Army Cold Regions Research and Engineering Laboratory.
URL: http://www.crrel.usace.army.mil/sid/personnel/perovichweb/photogallery/
photo00008999/real.htm
Last access: 29.06.2009
Ridged ice
Photography
National Snow and Ice Data Center, USA
URL: http://nsidc.org/seaice/characteristics/features.html
Last access: 29.06.2009
Nilas in Buffin bay, Arctic, photograph taken in September 2005
Photography
The image is a Wikimedia Commons file created by User: Mila Zinkova under the terms of the GNU Free Documentation Licence, Version 1.2.
URL: http://commons.wikimedia.org/wiki/File:Nilas_Sea_Ice1.jpg
Last access: 11.06.2009
Ice formation
Graphic
National Snow and Ice Data Center, USA
URL: http://nsidc.org/seaice/characteristics/formation.html
Last access: 29.06.2009
Ice growth
Graphic
Environment Canada
URL: http://ice-glaces.ec.gc.ca/App/WsvPageDsp.cfm
Last access: 22.07.2009
Sea ice climatologies
Graphic
National Snow and Ice Data Center, USA
URL: http://nsidc.org/sotc/sea_ice.html
Last access: 01.07.2009
New ice
Photography
U.S. Geological Survey, photo by Jessica Robertson
URL: http://www.usgs.gov/journals/arctic/2008/10/
Last access: 01.07.2009
Thinning ice north of Siberia
Satellite image
NASA Visible Earth, Jacques Descloitres, MODIS Land Rapid Response Team
URL: http://visibleearth.nasa.gov/view_rec.php?id=1915
Last access: 15.08.2009
Multiyear ice
Photography
U.S. Geological Survey, photo by Jessica Robertson
URL: http://www.usgs.gov/journals/arctic/2008/10/
Last access: 01.07.2009
First year ice
Photography
Don Perovich, U.S. Army Cold Regions Research and Engineering Laboratory.
URL: http://www.crrel.usace.army.mil/sid/personnel/perovichweb/photogallery/
photo00008999/real.htm
Last access: 01.07.2009
Drilling to measure ice thickness
Photography
Alfred Wegener Institute for Polar and Marine Research Bremerhaven
URL: http://www.awi.de/de/aktuelles_und_presse/pressemitteilungen/detail/item/higher_water_temperatures_and_reduced_ice_cover_in_the_arctic_ocean/?cHash=e637ce40aa Press release.
Last access: 20.08.2009
Mosaic of MODIS images
Satellite image
Terry Haran, National Snow and Ice Data Center,
URL: http://nsidc.org/sotc/sea_ice_mosaic.html
Last access: 20.08.2009
Sea ice concentration
Satellite image
National Snow and Ice Data Center, USA
URL: http://nsidc.org/cryosphere/glance/ for an image 2 days old (data changes daily).
Last access: 24/07/2009
Measuring sea ice thickness
Diagram
Peter Lemke, Alfred Wegener Institute for Polar and Marine Research Bremerhaven
URL: http://envisat.esa.int/envschool_2008/ Envisat summer school.
Last access: 20.08.2009
Sea ice extent time series
Graph
NOAA, USA
URL: http://www.arctic.noaa.gov/essay_untersteiner.html
Last access: 01.07.2009
Sea ice extents
Graphs and images
National Snow and Ice Data Center, USA
URL: http://nsidc.org/data/seaice_index/
Last access: 15.08.2009
March/September sea ice extent
Graph
NOAA, USA
URL: http://www.arctic.noaa.gov/reportcard/seaice.html
Last access: 01.07.2009
MODIS image of the Bering Straits April 2002
Image
NASA, USA
URL: http://visibleearth.nasa.gov/view_rec.php?id=3742
Last access: 01.07.2009
MODIS image of the Bering Straits May 2002
Image
NASA, USA
URL: http://visibleearth.nasa.gov/view_rec.php?id=3744
Last access: 17.08.2009
AMSR-E on Aqua- sea ice extent
Animation
NASA, USA
URL: http://svs.gsfc.nasa.gov/goto?3466
Last access: 14.08.2009
Sea Ice Retreat in the East Siberian Sea
Image
NASA, USA
URL: http://earthobservatory.nasa.gov/IOTD/view.php?id=7970
Last access: 01.07.2009
Political map of the Arctic
Map
UNEP/GRID Maps, Designer Hugo Ahlenius
URL: http://maps.grida.no/go/graphic/ arctic-map-political
Last access: 01.07.2009

6. Plankton Blooms

Chlorophyll concentrations as measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite and the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite between March 21 and June 20, 2006.
Image
NASA, USA
URL: http://earthobservatory.nasa.gov/IOTD/view.php?id=6735
Last access: 06.10.2009
Assorted diatoms (phytoplankton) found living between crystals of annual sea ice overlying McMurdo Sound, Antarctica.
Photograph
NOAA At The Ends of the Earth Collection, USA. Image digitized from original 35mm Ektachrome slide (1983). Image ID: corp2365, Photographer: Prof. Gordon T. Taylor, Stony Brook University Photo Credit: NSF Polar Programs
URL: http://www.photolib.noaa.gov/htmls/corp2365.htm
Last access: 06.10.2009
Predicted phytoplankton response to increased temperature in ocean surface waters.
Graphic
Nature Reprinted by permission from Macmillan Publishers Ltd: Nature Oceanography: Plankton in a warmer world Scott C. Doney Nature 444, 695-696(7 December 2006) doi:10.1038/444695a, copyright 2006.
URL: http://www.nature.com/nature/journal/v444/n7120/fig_tab/444695a_F1.html
Last access: 06.10.2009
Average ocean chlorophyll concentration measured by SeaWiFS since launch in 1997 until early 2004
Image
NASA Visible Earth, USA
URL: http://visibleearth.nasa.gov/view_rec.php?id=16682
Last access: 06.10.2009
Chlorophyll June, September, December 2007, March 2008
Images
NASA , USA, Ocean Color Web
URL: http://oceancolor.gsfc.nasa.gov/ and then link to level 3 browser.
Last access: 06.10.2009
Chlorophyll June 2007 - June 2008
Animation
NASA , USA, Ocean Colour Web
URL: http://oceancolor.gsfc.nasa.gov/ and then link to level 3 browser for monthly images.
Last access: 06.10.2009

7. Exercises

Worksheet: Temperature Trend in the Wadden Sea 1: Annual and Monthly Mean Values

Monitoring station of the University of Oldenburg at Spiekeroog in the Wadden Sea. On the left hand side, the research ship Senckenberg.
Photography
Thomas Badewien, Marine Physics, University of Oldenburg, Germany
URL: http://las.physik.uni-oldenburg.de/wattstation/
Last access: 12.07.2009

Worksheet: Temperature Trend in the Wadden Sea 2: Linear Regression Analysis

Time series of air (red curve) and seawater temperature (blue curve) and seawater salinity measured between October 2002 and March 2009.
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Water temperature near Spiekeroog island in October
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Water temperature near Spiekeroog island in October
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany

8. Learn more

Supplement 1: Point Clouds and Linear Regression Lines

Point cloud P(xi,yi)
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Straight line and projected points P(xi,f(xi))
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Differences between data and points on a line
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Centroid P(x,y) of the data points
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Centroid P(x,y) and best-fit line f(x)=ax+b
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Water temperatures in October near Spiekeroog island
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Explanation of the position of P(x5,y5) in two steps
Graph
Rainer Reuter, Marine Physics, University of Oldenburg, Germany
Supplement 5: Ice in the Arctic
Albedo for ice and water
Diagram
National Snow and Ice Data Center, USA
URL: http://nsidc.org/seaice/processes/albedo.html
Last access: 03.07.2009
Surface roughness and scattering
Graphic
Natural Resources Canada
URL: http://www.ccrs.nrcan.gc.ca/resource/tutor/stereo/chap5/chapter5_9_e.php
Last access: 14.09.2009
Multi-angle images of Hudson Bay and James Bay
Image
JPL, NASA, USA
URL: http://www-misr.jpl.nasa.gov/gallery/galhistory/2000_may_17.html
Last access: 17.08.2009
Ice Floe, cross section
Diagram
Wikimedia, Amanda Grobe and Hannes Grobe, Alfred Wegener Institute for Polar and Marine Research.
URL: http://commons.wikimedia.org/wiki/File:Ice-floe_params_hg.png
Last access: 17.08.2009
Drift ice in the Labrador Sea
Photo
NASA, Astronaut Photography of Earth, USA
URL: http://eol.jsc.nasa.gov/ mission=ISS006 roll=E frame=46540
Last access: 17.08.2009
Arctic sea ice
Satellite image
Wikimedia, Jerzy Strzelecki/Polar Regions
URL: http://commons.wikimedia.org/wiki/File:Floe_ice_(js).jpg,
Last access: 17.08.2009
Ice Floes off Labrador
Satellite image
NASA Visable Earth, USA
URL: http://visibleearth.nasa.gov/view_rec.php?id=17791
Last access: 17.08.2009
Polynya North of Alaska
Satellite image
NASA Earth Observatory, USA
URL: http://earthobservatory.nasa.gov/IOTD/view.php?id=6963
Last access: 17.08.2009
Arctic sea ice
Satellite image
NASA Earth Observatory, USA
URL: http://earthobservatory.nasa.gov/IOTD/view.php?id=7370
Last access: 17.08.2009
Arctic National Wildlife Refuge and Beaufort Sea
Satellite image
NASA Earth Observatory, USA
URL: http://earthobservatory.nasa.gov/IOTD/view.php?id=1710
Last access: 03.07.2009
North coast of Island of Hokkaido, Japan
Satellite image
NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team
URL: http://asterweb.jpl.nasa.gov/gallery-detail.asp?name=aniva
Last access: 03.07.2009
Bering Strait, from ATSR
Satellite image
ESA Earthnet
URL: http://earth.esa.int/cgi-bin/satimgsql.pl?pf=498
Last access: 17.08.2009
Foxe Basin in North-east Canada, from AATSR
Satellite image
ESA
URL: http://www.esa.int/esaEO/SEMLWG3AR2E_index_0.html
Last access: 17.08.2009
Ice as seen by blue light
Satellite image
NASA MODIS
URL: http://modis-snow-ice.gsfc.nasa.gov/040301arctic.html
Last access: 17.08.2009
Frequencies, wavelengths and band letters
Diagram
Radar Tutorial
URL: http://www.radartutorial.eu/07.waves/wa04.en.html#this
Last access: 17.08.2009
Cryosat measuring freeboard
CGI
ESA CryoSat-2
URL: http://www.esa.int/esaLP/ESA0DL1VMOC_LPcryosat_1.html
Last access: 17.08.2009
Sea ice concentration from AMSR-E
Satellite image
The National Snow and Ice Data Center
URL: http://nsidc.org/arcticseaicenews/2009/070609.html
Last access: 17.08.2009
Cryosat
CGI
ESA CryoSat-2
URL: http://www.esa.int/esaLP/ESA0DL1VMOC_LPcryosat_1.html
Last access: 17.08.2009
Freeboard and ice thickness
Diagram
Ron Kwok, NASA/JPL
URL: http://www.nasa.gov/topics/earth/features/icesat-20090707.html
Last access: 17.08.2009
Trend in winter sea ice thickness
Diagram
Ron Kwok, NASA/JPL
URL: http://www.nasa.gov/topics/earth/features/icesat-20090707.html
Last access: 17.08.2009
ICESat
CGI
NASA ICESat
URL: http://icesat.gsfc.nasa.gov/
Last access: 17.08.2009
GLAS instrument
Diagram
NASA, about GALS
URL: http://glas.gsfc.nasa.gov/about.html
Last access: 17.08.2009