Friday, July 05, 2019

Mapping Historical Sea Ice Extent


John Nelson has created a series of maps to show how the sea ice extent in the Arctic and Antarctic changes over the course of the year. He has also mapped out how these sea ice extents have changed over the last 40 years.

Historic Sea Ice Events starts with a fantastic animated map which shows the freezing and thawing of the water at the poles over 12 months. This animation provides a great overview of the seasonal changes at the poles. Historic Sea Ice Extents also includes a series of static maps to visualize the historical records of sea ice extent at both poles for every month over the last 40 years. On these maps the color of the sea ice extent changes by year. The yellow lines on these maps show the sea ice extent in the most recent years, while purple lines show the more historic records of sea ice levels.

These maps clearly reveal that the levels of sea ice at both poles has been dramatically decreasing in recent years as a result of global heating.


John Nelson's maps use data from the National Snow and Ice Data Center. The Center has created its own series of interactive maps which visualize Satellite Observations of Arctic Change. These maps allow you to see how sea ice, snow cover and frozen ground have all been shrinking during the 21st Century. Other maps plot air temperature changes in the Arctic and the changes to Arctic vegetation.

Global warming is causing observable changes to ecological systems in the Arctic. Air temperatures in the Arctic are rising and sea ice extent is declining. Even Arctic vegetation is changing with tundra being replaced by shrubs. Each of the NSIDC interactive maps uses NASA satellite data and research to plot changes to the Arctic from 1979 to 2015. The maps allow you to observe the data for each year in this period to observe how global heating has effected the ecological systems of the Arctic.

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