Seasonal Changes in Seasonal Changes in Sea Ice AreaSea Ice Area

Earth’s Cryosphere consists of all forms Earth’s Cryosphere consists of all forms of water in the solid state and includes:of water in the solid state and includes:

Sea IceSea Ice

Lake IceLake Ice

SnowSnow

GlaciersGlaciers

Ice CapIce Cap

Sheet IceSheet Ice

PermafrostPermafrost

Ice in CloudsIce in Clouds

Graphs Reveal Seasonal Patterns of Graphs Reveal Seasonal Patterns of Changes in Sea IceChanges in Sea Ice

Half of you will interpret a graph for the Half of you will interpret a graph for the Southern Hemisphere.Southern Hemisphere.

Half of you will interpret a graph for the Half of you will interpret a graph for the Northern Hemisphere.Northern Hemisphere.

Note: Later this week, you will actually make sea ice.Note: Later this week, you will actually make sea ice.

The Northern Hemisphere group The Northern Hemisphere group will interpret this graph.will interpret this graph.

http://arctic.atmos.uiuc.edu/cryosphere/

The Southern Hemisphere group The Southern Hemisphere group will interpret this graphwill interpret this graph..

When was the maximum of sea When was the maximum of sea ice area for the ice area for the entire entire Earth Earth during the 365 day period?during the 365 day period?

Maximums and minimums of the sea ice area Maximums and minimums of the sea ice area graphs correspond closely with the changes in graphs correspond closely with the changes in “Astronomical“ seasons in both Hemispheres.“Astronomical“ seasons in both Hemispheres.

http://okfirst.mesonet.org/train/meteorology/Seasons.html

Why would the sea ice minimum Why would the sea ice minimum occur around the time of a Fall occur around the time of a Fall Equinox rather than around the Equinox rather than around the time of a Summer Solstice?time of a Summer Solstice?

What are some additional questions What are some additional questions that could be posed that relate to that could be posed that relate to

the sea ice area graphs?the sea ice area graphs?

Research ActivitiesResearch Activities

• Use images from web sites to Use images from web sites to monitor snow cover and sea ice in monitor snow cover and sea ice in the Polar Regions and at lower the Polar Regions and at lower latitudes during the school year.latitudes during the school year.

• Use archives on web sites to Use archives on web sites to compare the present accumulation of compare the present accumulation of sea ice and snow with past years and sea ice and snow with past years and with “normal” years.with “normal” years.

The Cryosphere Today’s web site can be used to The Cryosphere Today’s web site can be used to compare the extent of sea ice and snow cover on the compare the extent of sea ice and snow cover on the

same date in different years.same date in different years.(The color scale applies only to the extent of sea ice.)(The color scale applies only to the extent of sea ice.)

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=11&fd=15&fy=2008&sm=02&sd=15&sy=2009

One More QuestionOne More Question

How do scientists obtain How do scientists obtain the data necessary to construct the data necessary to construct the graphs that you interpreted the graphs that you interpreted today?today?