Current Events

  • Irish Chronicles Document Links Between Volcanoes and Weather
    A study of over 40,000 written entries in Irish Annals and ice core measurements shows a strong corr...Read more

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    Irish Chronicles Document Links Between Volcanoes and Weather

    A study of over 40,000 written entries in Irish Annals and ice core measurements shows a strong correlation between the occurrence of volcanic eruptions and extreme cold weather in Ireland over a 1200 year period. Data analyzed in this study cover the period from 431 to 1649, during which time up to 48 volcanic eruptions are identified in Greenland ice core records through deposition of volcanic sulfate in annual layers of ice. You can find the study (open access), published on 6 June 2013 in IOP Publishing's journal Environmental Research Letters, at http://iopscience.iop.org/1748-9326/8/2/024035/article. Find out more about how volcanoes can influence climate.
  • EF-5 Tornado in El Reno, Oklahoma Widest Ever Recorded in US
    The EF-5 tornado that hit El Reno, Oklahoma on May 31st was the widest ever recorded in the US, acco...Read more

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    EF-5 Tornado in El Reno, Oklahoma Widest Ever Recorded in US

    The EF-5 tornado that hit El Reno, Oklahoma on May 31st was the widest ever recorded in the US, according to the National Weather Service in Norman Oklahoma. The tornado, which remained on the ground for 40 minutes and reached 2.6 miles across (4.2 km), took the lives of 18 people including storm chasers Tim Samaras, Paul Samaras and Carl Young. For more information on the tornado, visit http://ow.ly/i/2hfDG.
  • Atmospheric CO2 Level Tops 400 ppm
    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm rep...Read more

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    Atmospheric CO2 Level Tops 400 ppm

    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well. The level of atmospheric greenhouse gases continues to increase, now over 120 ppm since the Industrial Revolution began. For more on the Keeling Curve, see http://keelingcurve.ucsd.edu/. Find out more about greenhouse gases and warming.

Compare Images of Antarctic Sea Ice Extent Side-by-side

The pictures below show sea ice around the South Pole. Click on the popup menus above the pictures to choose which pictures to look at. You can look at two pictures at once and compare them.

Try this:

  • compare the sea ice in February and September for the same year (like February 2000 and September 2000)
  • compare the sea ice in February for two different years (like February 1979 and February 2010)
  • compare the sea ice in September for two different years
  • click here if you want to look at sea ice in the northern hemisphere

Select a month:
... and a year:

Select a month:
... and a year:

The images are courtesy of the National Snow and Ice Data Center (NSIDC).

Sea ice builds up during the winter when it is cold. When is there the most sea ice? There is usually a lot of sea ice in early spring, right after winter ends, around September. Remember, in the southern hemisphere, summer and winter happen at the opposite times of year from the northern hemisphere!

Over the summer, when it is warm, the sea ice melts. When is there the least sea ice? Since a lot of ice melts in the summer, there is usually much less sea ice in early fall around February, right after the end of summer.

The pink line in the pictures shows where the edge of the sea ice is, on average, in that month. Compare the edge of the ice in 1979 to the pink line. Now compare the edge of the ice in 2010 to the pink line. Do you see any difference?

Click here to see a movie of changes in sea ice over seven years (2002 to 2008). Watch how the ice melts in the summer and freezes and grows in the winter.

If you want to see more pictures of sea ice, go to the NSIDC web site to:

Last modified October 8, 2010 by Randy Russell.

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