e+block+snow+and+ice

Jasmine, Charlotte, Natashia, and Dustin :D

Northern Hemisphere Snow Cover Extent

Satellites have shown that overall the snow cover in the Northern Hemisphere decreased over the last few years. The picture below shows the snow cover in the Northern Hemisphere from February 20th 2013. The yellow part represents the ice cover, the white part the snow cover.C



The graph below shows the anomalies of the snow cover per square kilometer in the Northern Hemisphere which occurred in winter from 1967 to 2012. The 0-line represents the average snow cover, which amounts to 45.2 million square kilometer. During the winter season 2011/2012 the Northern Hemisphere experiences the 14th largest snow cover extent at 590,000 square miles above the average snow cover (45.2 million square miles). In spring season 2012 the snow cover extent constricted to a blow-average extent at 1.9 million square miles. Over the 47-year record, the snow cover extent in the Northern Hemisphere has only changed about 0.1 percent. The snow cover extent decreased in the spring season about 2.2 percent per decade.C A picture of snow cover in Cordova, Alaska J The graph below shows the snow cover extent in North America compared to Eurasia from October, November-December, January-February, and March-April from 1910 until 1990. Striking is the difference in the snow cover extent in October which is at approximately at 9*10^6 square kilometer and at approximately at 22*10^6 square kilometer in North America. Both, Eurasia and North America have their highest snow cover extent rate in January-February.C The snow cover extent for north america stays at a level between about 22 and 27 throghout the years(1910-1990). At this rate the snow cover should be in that range for the fallowing years.J

The snow cover extent really surprise me. We does studied in class that the snow cover extent decreases. It is a popular topic in newspapers and on TV. The article I had to summarize did not give specific information about why the snow cover changes or what will happen in the future but it obviously affected by, and relates to global warming. We learned in class that when the snow cover decreased, less snow will reflect less sunlight which will lead to more global warming. It was still interesting to read about the snow cover extent in the Northern Hemisphere because I learned more about the actual data, I would have never learned about otherwise.

During the winter of 2011/12 the Northern Hemisphere has had its 14th largest and its 33rd smallest snow cover extent on the record at 228,000 square miles above the average 17.5 million square miles of snow cover. The winter snow cover extent hasent changed by much in the last 47 years it has been recorded ,with only about a seasonal increase of 0.1 percent every 10 years.in the spring the snow cover extent is below average.The seasonal snow cover extent was 734,000 square miles and was ranked as the 6th smallest seasonal extent recorded. The spring snow cover extent has decreasing by a rate of 2.2 percent every 10 years. In the winter North American in 2011/12 snow was limited. It was smallest since the winter of 1999/2000 and the 4th smallest seasonal snow cover recorded at 243,000 square miles below the average of 6.6 milion square miles.In the winter of 2009/10 and 2011/12 north america had its largest and 3rd largest snow cover extent. The spring snow extent was 359,000 miles below average and the 3rd smallest on record. In Eruasia, the snow cover extent in the winter of 2011/12 was above average.The seasonal snow cover extent was 463,000 square miles above average and was ranked as the 4th largest on recored. In spring the snow cover extent was 386,000 square miles below average and was the 12th smalest on recored. Summary by Jasmine.J

[] [] North America and Eurasia, the snow cover decreases rapidly. A new record low was hit in June 2012, the 5th time in a row for Eurasia and the 3rd time for North America in the last 5 years.

The map below shows the snow cover anomalies from June 2012 compared to the long time average (1971-2000). The brown spots show where places experiences 40 percent less snow cover than expected based on average, the blue spots where the snow cover was 40 percent higher than expected. Please take a moment and compare the brown spots to the blue spots. It is hard to ignore that most of the areas on the map are brown, therefore had much less snow than they should have had.

In average the total loss of snow cover from 1971 – 2000 is 17.6 % per decade! Far too much to not affect the oceans water level. [] Poem Forecast: Winter StormShovel handy, boots by door, Let It Snow, Snow, SnowSnowed all day longWinter Season has begun, The land is turned whiteSnow came silentlyFell all day, turned Earth to aWinter WonderlandWhile waiting for SpringSnow transformed the land toa white fantasySnow came in the nightTurned the whole world whiteA cold wintry siteThe Blizzard WizardWaved His wand, crystal stardust fellAnd ice fairies dancedSnow falling todayCreative juices flowingWriter’s Block is gone Nancy Chambers.J.J [] Vocabulary: Snow cover: When something in covered in snow. The average snow cover depth in the United States is 7.3 inches Northern Hemisphere: The half of Earth that it north from it's equator Winter Season: from December to February Spring Season: from March to May Eurasia: The combined continental landmasses Europa and Asia Vocabulary: Snow cover-covered with snow Northern Hemisphere - The half of the earth that is north of the equator. Eurasia- a term that is used to describe the combined continental land mass of Europe and Asia. Citations: [] [] [] [] The snow cover extent information given for the northern hemisphere and the north america didnt really suprise me.I think I wasnt suprising becuase I had prior information about this and I live in north america so I know whats going on over here.What was really suprising to me was the snow cover extent report for eruasia because I had no prior information about it. I had no idea that they got so much snow in the winter there. by Jasmine.J


 * Sea Ice Extent**

The Arctic sea ice extent for January 2013 was far below average because of the extensive open water in the Barents Sea and near Svalbard. Arctic sea ice usually expands during the start of the cold season to the warm season, March is the cold seasons maximum were the ice is extended the most for the year and September is the warm seasons minimum were the ice starts to go down. According to the NSIDC (National Snow and Ice Data Center) in March 2012 the monthly average Arctic sea ice extent was 5.87 million square miles, 3.42 percent below the 1979-2000 long-term average. It was also the ninth smallest maximum extent on recorded, this happen between the year 2004 to 2012. In September 2012 the Arctic sea ice extent had dropped, according to NSIDC, it dropped below the to previous lowest Arctic ice extent which was on September 18, 2007 at 1.61 million square miles. The sea ice will continue to melt until it hits it annual minimum which is 1.32 million square miles, but during the 2012 annual minimum was 293,000 square miles below the previous record minimum and 49 percent below the 1979-2000 average. During the Arctic ice melt between March and September, the amount of ice that was lost was 4.57 million square miles. This was the largest Arctic ice melt since the ice melt season in 2008 which lost 4.11 million square miles of ice. Now in January 2013 the Arctic sea ice extent was lower than last year, it was at was 5.32 million square miles. This was the sixth lowest on recorded and was 409,000 square miles below the 1979 to 2000 average for the month. And now for the past ten years the Arctic sea ice extent has been dropping farther below its 1979-2000 average.


 * [[image:http://www1.ncdc.noaa.gov/pub/data/cmb/images/global-snow/2012/ann/Arctic_daily_seaice-t.png width="335" height="265" caption="March 2012 Arctic Sea ice" link="http://www1.ncdc.noaa.gov/pub/data/cmb/images/global-snow/2012/ann/Arctic_daily_seaice.png"]] ||
 * March 2012 Arctic Sea ice ||

This graph show the Arctic sea ice extent for the year 2012 it shows the daily by mouth recording from the NSIDC, the red line shows the Arctic sea ice fro 2012 and the black line is the average of the sea ice extent since 1979-2000.
 * [[image:http://www1.ncdc.noaa.gov/pub/data/cmb/images/global-snow/2012/ann/Sept16_2012_arcticice-t.png width="295" height="350" caption="September 2012 Arctic Sea ice" link="http://www1.ncdc.noaa.gov/pub/data/cmb/images/global-snow/2012/ann/Sept16_2012_arcticice.png"]] ||
 * September 2012 Arctic Sea ice ||

This picture shows the Arctic sea ice extent during the melting in September 2012. The orange line shows the Average for the sea ice extent for the melting sea and the white shows the Arctic sea ice for 2012. This picture shows the January 2013 Arctic sea ice extent. The purple line is the sea ice extent and the white is the ice for January. (The small black cross shows the north pole).

In the southern part of the world in Antarctica sea extent minimum for September 2012 was at 7.51 million square miles. This was the largest maximum extent of Antarctic sea ice extent on record and passed the previous record of 7.47 million square miles in September 2006. In January 2013 NSIDC saw an unusual northward excursion of sea ice. The ice edge was found approximately 124 to 186 miles beyond its typical location, which shows that the ice in Antarctic sea ice is extent is doing better than the sea ice extent in the Arctic.
 * [[image:http://www1.ncdc.noaa.gov/pub/data/cmb/images/global-snow/2012/ann/Antarctic_daily_seaice-t.png width="300" caption="2012 Daily Antarctic Sea Ice Extent" link="http://www1.ncdc.noaa.gov/pub/data/cmb/images/global-snow/2012/ann/Antarctic_daily_seaice.png"]] ||
 * 2012 Daily Antarctic Sea Ice Extent ||

This Graph show that the Antarctic sea ice extent for 2012 is the red line and show that is the highest sea extent than in the past fun. This picture shows the sea ice extent in January 2013. The purple line shows the average sea ice extent for Antarctic and the white is the ice which most of it is past its average.

During the sea ice extent the volume of the sea ice has been going below average over the past years. So not only is the sea ice extent is going below average also is the volume of the ice is as well. Sea ice volume is an important climate indicator that depends on both the ice thickness and extent, therefore more directly tied to climate forcing than extent alone. The Arctic sea ice volume reached a monthly low value during September 2012, at 3,400 km3, the smallest monthly sea ice volume on record. the


 * [[image:http://www.skepticalscience.com//pics/arctic-sea-ice-min-volume-comparison-1979-2012-v3.jpg width="383" height="177" caption="PIOMAS cubes"]] ||
 * PIOMAS cubes ||

This graph shows Arctic sea ice volume at the sea ice extent for the minimum in late September of 2012. It shows that the volumes of the ice has gone down than the ice volume in 1979. This graph also show the sea ice extent, the red line with the red triangles shows the ice volume for 2012. It is has the lowest volume out of the others ice volume in the past years.

From seeing all the numbers for the sea ice extent for the Arctic and to see how the sea ice extent continues to go down. It seems that the warm weather that is happening now is effecting the Arctic sea ice extent. I also shows that the climate for the Arctic has change over the years because of the global warming around the world and interferes with the ice in the north and the south poles. Then seeing that in the Antarctic has a bigger sea ice extent in 2012-2013 then in the Arctic sea ice extent in 2012-2013, does this show that the climate and the temperature is different around the world? That the south pole has colder weather than the north pole that explains the sea ice extent for the Arctic. The Arctic summer sea ice is shrinking and the Arctic has lost lots of ice through out the years mostly now in 2013 because the sea ice extent didn't reach its 1979-2000 maximum sea ice extent.

Vocabulary: Sea Ice Extent- The latitudinal ocean area that is covered by ice at any given time Extent- The area covered by something Maximum- the sea ice extent occurs in late winter Minimum- The sea ice extent in the early spring Volume- the measuring of the amount of space inside of a solid figure Global warming- The gradual increase in the temperature of the earth's atmosphere

citations- [] [] []

Arctic summer sea ice is shrinking much more rapidly than the rate at which Antarctic winter sea ice is expanding. Over the 1979-2012 record, the Arctic has experienced significant ice loss, while the growth of Antarctic sea ice has been slight. The September 2012 record low Arctic sea ice extent was 6.2 standard deviations below its 1979-2000 average, while the record large Antarctic sea ice extent was 2.1 standard deviations above its 1979-2000 average. Differences in hemispheric weather patterns, ocean currents, and geography partially account for these differing sea ice trends. A more detailed description of these differences is available through the [|NSIDC] .