Name: ________________________
Earth Science
Date: ____________
Landscapes Unit
Arctic Sea Ice
Objectives
1. Students will construct graphs of the extent of sea ice over time.
2. Students will use technology to analyze data and draw conclusions
about natural phenomena in the Arctic
3. Students will use data to explain the relationship between natural
occurrences and changes to world climate
Background Information
Water cycle diagrams often summarize the water cycle in a qualitative
way, noting reservoirs and flows. Reservoirs are places where water is
"stored", or where it stays for some period of time. The oceans, glaciers and
ice caps, lakes, and the atmosphere are some examples of reservoirs. Flows
or pathways are the routes water takes between reservoirs. Evaporation
moves water from the oceans to the atmosphere. Precipitation moves liquid
(rain) or solid (snow) water from the sky back to Earth's surface. Snowmelt
runoff turns solid water into a liquid that flows down rivers to the sea. The
amount of time that water spends, on average; in a reservoir is
called reservoir time.
Note that "water", in this context, means the chemical substance H2O,
whether in liquid, solid, or gaseous form. Water in oceans and lakes is, of
course liquid; but it is solid ice in glaciers, and gaseous water vapor in the
atmosphere.
Name: ________________________
Earth Science
Date: ____________
Landscapes Unit
How much water is there in the water cycle?
A quantitative look at the water cycle adds context to a water cycle diagram.
For example, the oceans are by far the largest reservoir, containing between
1.35 and 1.4 x 109 km3 of water; this is more than 95% of the water in the
cycle.
And how much of it is moving from place to place?
The rate of a flow, commonly expressed as cubic kilometers per year, can be
measured worldwide. For example, total global precipitation is about
505,000 km3 per year.
How long does water spend in one place or another?
Reservoir time is highly variable, depending on the type of reservoir. For
example, water stays in the atmosphere for only nine days on average. By
contrast, once water reaches the ocean, it stays put for a very long time - an
average of more than 3,000 years. It is important to realize that reported
residence times are averages, and that the actual residence time for a given
water molecule may be far from the average. Water vapor that reaches the
stratosphere may remain there for a long time; water that flows into warm,
shallow coastal waters from a river may evaporate and leave the ocean very
quickly.
A few highlights of where water spends its time are below.
 Atmosphere: The residence time for water in the atmosphere is a
brief nine days; the shortest of any major reservoir.
 Ice Sheets: Water spends thousands, tens of thousands, or even
hundreds of thousands of years in a frozen state in an ice sheet before
returning to other parts of the water cycle. (For example, the oldest
ice found in Antarctica is about 900,000 years old.)
 Glaciers: Water resides in glaciers for less time than it does in ice
sheets, often about 20 -100 years.
 Snow: Water spends around 2 to 6 months as seasonal snow. Each
year approximately 11,000 km3 of water is in snow; about the same
amount melts into water.
A little water cycle accounting:
The overall water cycle "contains" between 1,386,000,000 and
1,460,000,000 km3 of water in various states (liquid, solid, or gaseous).
The vast majority of it, between 96.5 and 97.25%, is in the oceans. Only
about 3% of Earth's water is fresh water. About 2/3 of that is frozen in the
ice sheets near the poles and in glaciers. About 90% of the polar ice sheet
and glacial ice is in Antarctica; most of the rest is in Greenland; a tiny
fraction is locked up in mountain glaciers elsewhere. Most of the rest of the
Name: ________________________
Earth Science
Date: ____________
Landscapes Unit
fresh water is underground. Less than 1% of fresh water is on the surface in
lakes, wetlands, and rivers.
About 80% of rain falls directly into the ocean. However, more water
leaves the ocean via evaporation than enters the ocean as precipitation. The
opposite is true on land: less water evaporates over the land than falls onto
land as precipitation. Evaporation of water from the land happens directly
from lakes, puddles, and other surface water. And water also makes its way
into the atmosphere via plants and a process called transpiration.
Collectively, the water evaporated from the land and from plants is called
evapotranspiration.
Higher rates of evaporation over the ocean and more precipitation over
the land would present an imbalance if it were not for river runoff that
transports water from land to ocean. The accounting only works out if the
amount of runoff that flows in rivers to the ocean makes up for most of this
imbalance.
Standards
New York State
STANDARD 1—Analysis, Inquiry, and Design
Students will use mathematical analysis, scientific inquiry, and engineering design, as appropriate, to
pose ques- tions, seek answers, and develop solutions.
Name: ________________________
Earth Science
Date: ____________
Landscapes Unit
STANDARD 2
Students will access, generate, process, and transfer information, using appropriate technologies.
1.2g
Earth has continuously been recycling water since the outgassing of water early in its history.
This constant recirculation of water at and near Earth’s surface is described by the hydrologic (water)
cycle.
2.1b
The transfer of heat energy within the atmosphere, the hydrosphere, and Earth’s interior results in
the formation of regions of different densities. These density differences result in motion.
2.1i
Seasonal changes can be explained using concepts of density and heat energy. These changes
include the shifting of global temperature zones, the shifting of planetary wind and ocean current patterns,
the occurrence of monsoons, hurricanes, flooding, and severe weather.
Hypothesis – What is the relationship between the extent of sea ice and
time in years?
Independent Variable
Dependent Variable
Procedure
1. Go to Mr. Mac’s Science Classes
2. Click on “Earth Science.”
3. Click on “Changing Climate e-Portfolio.”
4. Click on “Arctic Sea-Ice Data.”
5. Construct a graph using Microsoft Excel. Follow the instructions below:
a. Open up the “Arctic Sea Ice Data” using Microsoft Excel.
b. For your assigned month or months, highlight the data and click
on “Charts.”
c. Select “X Y (Scatter).”
d. Select “Smooth Marked Scatter.”
e. Once your graph has been created, select “Chart” to move chart
to new sheet and label it by month.
f. “Add Trendline” by clicking on one of the points on the graph,
and right click on a particular point.
g. Make sure your graph is labeled by month, and scale your graph
so that the y-axis maximum is set to 20, and y-axis minimum is
set to 0.
6. Save as a PDF file and upload your completed graph to Google Docs,
make sure you load it using your name and the date assigned.
7. Share with everyone in class. Find your block and share with the class.
Name: ________________________
Earth Science
Date: ____________
Landscapes Unit
Analysis and Conclusion
1. What is the largest reservoir of water and how much water does it
hold? What is the reservoir time at this location?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
2. How does the reservoir time of water in a glacier compare to in the
ocean?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
3. Based on the data and graph on the extent of sea ice, what pattern or
trend do you notice?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
4. Give a scientific explanation for the trends that you observed in your
graph.
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
5. Compare your graph to others, what pattern or trend do you notice?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
Name: ________________________
Earth Science
Date: ____________
Landscapes Unit
6. Give a scientific explanation for the trends that you observed in
comparing the graphs from other groups.
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
7. Based on the data and graphs from the entire class, what is your
conclusion? Does it agree or disprove your hypothesis? Explain.
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
8. Explain how you think it would be different from sea ice data taken
from Antarctica.
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
Links
 Arctic Sea Ice animation
https://spark.ucar.edu/video/sea-ice-extent-maps-animate-arctic