For Educators

A giant explosion of magnetic energy from the sun, called a coronal mass ejection, slams into and is deflected completely by the Earth's powerful magnetic field. The sun also continually sends out streams of light and radiation energy. Earth's atmosphere acts like a radiation shield, blocking quite a bit of this energy. Much of the radiation energy that makes it through is reflected back into space by clouds, ice and snow and the energy that remains helps to drive the Earth system, powering a remarkable planetary engine — the climate. It becomes the energy that feeds swirling wind and ocean currents as cold air and surface waters move toward the equator and warm air and water moves toward the poles — all in an attempt to equalize temperatures around the world.

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A jury appointed by the National Science Foundation (NSF) and Science magazine has selected "Excerpt from Dynamic Earth" as the winner of the 2013 NSF International Science and Engineering Visualization Challenge for the Video category. This animation will be highlighted in the February 2014 special section of Science and will be hosted on ScienceMag.org and NSF.gov This animation was selected for the Computer Animation Festival's Electronic Theater at the Association for Computer Machinery's Special Interest Group on Computer Graphics and Interactive Techniques (SIGGRAPH), a prestigious computer graphics and technical research forum. This is an excerpt from the fulldome, high-resolution show 'Dynamic Earth: Exploring Earth's Climate Engine.' The Dynamic Earth dome show was selected as a finalist in the Jackson Hole Wildlife Film Festival Science Media Awards under the category "Best Immersive Cinema - Fulldome".

The cryosphere consists of those parts of the Earth's surface where water is found in solid form, including areas of snow, sea ice, glaciers, permafrost, ice sheets, and icebergs. In these regions, surface temperatures remain below freezing for a portion of each year. Since ice and snow exist relatively close to their melting point, they frequently change from solid to liquid and back again due to fluctuations in surface temperature. Although direct measurements of the cryosphere can be difficult to obtain due to the remote locations of many of these areas, using satellite observations scientists monitor changes in the global and regional climate by observing how regions of the Earth's cryosphere shrink and expand.

This animation portrays fluctuations in the cryosphere through observations collected from a variety of satellite-based sensors. The animation begins in Antarctica, showing some unique features of the Antarctic landscape found nowhere else on earth. Ice shelves, ice streams, glaciers, and the formation of massive icebergs can be seen clearly in the flyover of the Landsat Image Mosaic of Antarctica. A time series shows the movement of iceberg B15A, an iceberg 295 kilometers in length which broke off of the Ross Ice Shelf in 2000. Moving farther along the coastline, a time series of the Larsen ice shelf shows the collapse of over 3,200 square kilometers ice since January 2002. As we depart from the Antarctic, we see the seasonal change of sea ice and how it nearly doubles the apparent area of the continent during the winter.

From Antarctica, the animation travels over South America showing glacier locations on this mostly tropical continent. We then move further north to observe daily changes in snow cover over the North American continent. The clouds show winter storms moving across the United States and Canada, leaving trails of snow cover behind. In a close-up view of the western US, we compare the difference in land cover between two years: 2003 when the region received a normal amount of snow and 2002 when little snow was accumulated. The difference in the surrounding vegetation due to the lack of spring melt water from the mountain snow pack is evident.

As the animation moves from the western US to the Arctic region, the areas affected by permafrost are visible. As time marches forward from March to September, the daily snow and sea ice recede and reveal the vast areas of permafrost surrounding the Arctic Ocean.

The animation shows a one-year cycle of Arctic sea ice followed by the mean September minimum sea ice for each year from 1979 through 2008. The superimposed graph of the area of Arctic sea ice at this minimum clearly shows the dramatic decrease in Artic sea ice over the last few years.

While moving from the Arctic to Greenland, the animation shows the constant motion of the Arctic polar ice using daily measures of sea ice activity. Sea ice flows from the Arctic into Baffin Bay as the seasonal ice expands southward. As we draw close to the Greenland coast, the animation shows the recent changes in the Jakobshavn glacier. Although Jakobshavn receded only slightly from 1964 to 2001, the animation shows significant recession from 2001 through 2009. As the animation pulls out from Jakobshavn, the effect of the increased flow rate of Greenland costal glaciers is shown by the thinning ice shelf regions near the Greenland coast.

This animation shows a wealth of data collected from satellite observations of the cryosphere and the impact that recent cryospheric changes are making on our planet.

For more information on the data sets used in this visualization, visit NASA's EOS DAAC website.

Note: This animation is an update of the animation 'A Short Tour of the Cryosphere', which is itself an abridged version of the animation 'A Tour of the Cryosphere'. The popularity of the earlier animations and their continuing relevance prompted us to update the datasets in parts of the animation and to remake it in high definition. In certain cases, our experiences in using the earlier work have led us to tweak the presentation of some of the material to make it clearer. Our thanks to Dr. Robert Bindschadler for suggesting and supporting this remake.