Arctic Ice Melt

Projected Impacts of Climate Change
Projected impact of climate change. Future climate change and projected impacts: Increased growth and yield rates due to higher levels of carbon dioxide and temperatures could result in longer growing seasons. For example, in mid to high latitude regions, according to the Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment Report moderate local increases in temperature (1-2ºC) can have small beneficial impacts on crop yields. Stern Review/UNEP Source: http://maps.grida.no/go/graphic/projected-impact-of-climate-change

Ice Albedo
That the Arctic should be especially sensitive to climate change was recognized in the 19th century. The primary reason for this sensitivity is that an initial warming (or cooling) sets in motion a chain of events that amplify the warming or cooling. This chain of events is known as the albedo feedback. Albedo is a measure of how white, or reflective, a surface is. Source: http://www.arctic.noaa.gov/essay_serreze.html

Decline in Arctic Multiyear Sea Ice Coverage (1999-2009)
Decline in arctic multiyear sea ice coverage (1999-2009). Source: http://www.nasa.gov/topics/earth/features/seaice_status09_prt.htm Image Source: http://www.nasa.gov/images/content/324873main_kwokfig4_full.jpg

Arctic September Sea Ice Extent
Arctic September Sea Ice Extent: Observations and Model Runs (1950-2050). Source: http://www.ucar.edu/news/releases/2007/seaice.shtml Image Source: http://www.ucar.edu/news/releases/2007/images/arctic_sea_ice_extent6.jpg

Arctic Oscillation (AO) Anomaly December-January 2009/2010
Arctic Oscillation (AO) Anomaly, December-January 2009/2010. Source: http://www.columbia.edu/~jeh1/mailings/2010/20100127_TemperatureFinal.pdf

2010 - Arctic Multi Year Ice Loss
NOAA Arctic Report - multi-year ice loss. Source: http://www.arctic.noaa.gov/reportcard/seaice.html

2009-Sea Ice Volume Trend
NASA JPL Trend in winter sea ice volume (2004-2008). Source: http://www.nasa.gov/images/content/365871main_earth3-20090707-full.jpg

2009-Sea Ice Thickness Trend
Trend in winter sea ice thickness (2004-2008). Source: http://www.nasa.gov/images/content/365869main_earth2-20090707-full.jpg

2009-05 Sea Ice Age
These images show declining sea ice age, which indicates a thinning Arctic sea ice cover more vulnerable to melting in summer. Ice older than two years now accounts for less than 10% of the ice cover. http://www.nsidc.org/arcticseaicenews/2009/040609.html - http://www.nsidc.org/images/arcticseaicenews/20090406_Figure5.png

2009-04 Ice Mass Loss
2009 - As the melt season begins, the Arctic Ocean is covered mostly by first-year ice, which formed this winter, and second-year ice, which formed during the winter of 2007 to 2008. First-year ice in particular is thinner and more prone to melting away than thicker, older, multi-year ice. This year, ice older than two years accounted for less than 10% of the ice cover at the end of February. From 1981 through 2000, such older ice made up an average of 30% of the total sea ice cover at this time of the year. http://nsidc.org/arcticseaicenews/2009/040609.html

2008-09 Sea Surface Temperature Anomolies 2007-2009
Sea surface temperature anomalies for August 2008, expressed with respect to 1982 to 2006 mean, correspond closely with ice retreat. Blue line indicates ice edge; warm colors indicate positive sea surface temperature anomalies. http://www.nsidc.org/arcticseaicenews/2008/090408.html - http://www.nsidc.org/images/arcticseaicenews/20080904_Figure4.jpg

2008-09 Sea Ice Extent 1979-2008
Monthly August ice extent for 1979 to 2008 shows 2008 as the second-lowest August on record. http://www.nsidc.org/arcticseaicenews/2008/090408.html - http://nsidc.org/images/arcticseaicenews/20080904_Figure5.png

2008-09 Multiyear Ice Depletion 2007-2008
Comparison of sea ice age during the second full week of September reveals that the Arctic will enter the winter ice growth season with less multiyear ice (bright colors), but far more first-year ice (dark blue) this year than it did in 2007. White indicates water; black indicates land. http://www.nsidc.org/arcticseaicenews/2008/092408.html - http://www.nsidc.org/images/arcticseaicenews/20080924_Figure3.jpg

2008-08 Northwest passage open for second year in a row.
The Northwest Passage that Roald Amundsen navigated with great difficulty starting in 1903 is opening for the second year in a row, as shown in the AMSR-E sea ice product from the University of Bremen (Figure 4). http://www.nsidc.org/arcticseaicenews/2008/081108.html - http://www.nsidc.org/images/arcticseaicenews/20080811_Figure4.jpg

2008-05 Estimated sea ice extent - September minimum.
This bar plot shows estimates of sea ice extent at the 2008 September minimum based on known ice survival rates. The blue dotted line indicates the record-breaking minimum extent of 2007; the red dotted line shows the mean estimate based on all years between 1983 and 2007. http://www.nsidc.org/arcticseaicenews/2008/050508.html - http://www.nsidc.org/images/arcticseaicenews/200805_Figure4.png

2008-04 New ice growth over winter 2007/2008
Map of estimated ice age for the third week of March for 2007 (left) and 2008 (right). Dark blue indicates first-year ice; red indicates ice that is 6 years old or more; grey is land and white indicates areas where ice age is not tracked. Colleagues James Maslanik, Chuck Fowler, and Sheldon Drobot at the University of Colorado at Boulder developed this image.—Credit: Image from National Snow and Ice Data Center courtesy Maslanik, Fowler, Drobot http://www.nsidc.org/arcticseaicenews/2008/040708.html - http://www.nsidc.org/images/arcticseaicenews/200804_Figure4.png

2008-04 Ice Freeboard 2007-2008
Another way to study sea ice thickness is to look at freeboard, or the amount of ice and snow that protrudes above the water surface. Freeboard for winter 2007 (left) and 2008 (right). Purple indicates no freeboard; red indicates ice freeboard 80 centimeters (2.6 feet) thick or greater; grey is land and white indicates no data. Colleague Ronald Kwok from Jet Propulsion Laboratory supplied this image. http://www.nsidc.org/arcticseaicenews/2008/040708.html - http://www.nsidc.org/images/arcticseaicenews/200804_Figure6.png
2008 (1979-2008) Sea Ice Yearly Minimum w/Graph Overlay
The continued significant reduction in the extent of the summer sea ice cover is a dramatic illustration of the pronounced impact increased global temperatures are having on the Arctic regions. There has also been a significant reduction in the relative amount of older, thicker ice. Satellite-based passive microwave images of the sea ice cover have provided a reliable tool for continuously monitoring changes in the extent of the Arctic ice cover since 1979. The ice parameters derived from satellite ice concentration data that are most relevant to climate change studies are sea ice extent and ice area. This visualization shows ice extent in the background and ice area in the foreground. Ice extent is defined here as the integrated sum of the areas of data elements (pixels) with at least 15% ice concentration while ice area is the integrated sum of the products of the area of each pixel and the corresponding ice concentration. Ice extent provides information about how far south (or north) the ice extends in winter and how far north (or south) it retreats toward the continent in the summer while the ice area provides the total area actually covered by sea ice which is useful for estimating the total volume and therefore mass, given the average ice thickness. For more information about these ice datasets, see The Journal of Geophysical Research VOL. 113, C02S07, doi:10.1029/2007JC004257, 2008

2007-09 Northwest Passage Envisat ASAR
Envisat ASAR mosaic of the Arctic Ocean for early September 2007, clearly showing the most direct route of the Northwest Passage open (orange line) and the Northeast passage only partially blocked (blue line). The dark grey colour represents the ice-free areas, while green represents areas with sea ice. Source: http://www.esa.int/esaCP/SEMYTC13J6F_index_1.html

2007-08 Disappearance of old ice, 1981–2007
There seems to have been a transition to younger, thinner ice beginning in the late 1970s. This reflects not only trends towards more summer melt and less winter ice growth, but changing winds that have transported fairly thick ice out of the Arctic Ocean into the North Atlantic, and decreased the length of time that ice is "sequestered" in the Arctic Ocean where it might have a chance to grow thicker. http://www.nsidc.org/arcticseaicenews/2007.html
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