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Wednesday, April 14, 2010

6:30 p.m. - 8:00 p.m. Eastern time

NASA/UCAR: Effects of Climate Change: Oceans and Ice

Presented by: Dr. Lisa Gardiner

Effects of Effects of Climate Change: Climate Change: Oceans and IceOceans and IceA web seminar for the NSTA community A web seminar for the NSTA community By the UCAR Office of Education and Outreach,By the UCAR Office of Education and Outreach,with support from NASA.with support from NASA.

OverviewOverview

Melting snow and ice on landMelting snow and ice on landGlaciers Then and Now activityGlaciers Then and Now activity

Rising sea levelRising sea levelThermal expansion activityThermal expansion activity

Possible changes to ocean Possible changes to ocean circulationcirculation

Ocean acidificationOcean acidificationPresenter:Dr. Lisa GardinerEducational DesignerUCAR Office of Education and Outreach

Melting Snow and Ice on Melting Snow and Ice on LandLand

(with an activity about glaciers)(with an activity about glaciers)

Glaciers and Ice SheetsGlaciers and Ice Sheets

Continental glaciers (also Continental glaciers (also called ice sheets) cover called ice sheets) cover large areas at high large areas at high latitudes.latitudes.

Alpine glaciers (mountain Alpine glaciers (mountain glaciers) cover smaller, glaciers) cover smaller, high altitude areas at all high altitude areas at all latitudes.latitudes.

To be considered a To be considered a glacier, the ice must be glacier, the ice must be moving.moving.

Matanuska Glacier, AKCourtesy of N Gordon/UCAR

Changes in Glacial IceChanges in Glacial Ice

What can we What can we say about this say about this graph?graph?

[Type in the [Type in the Chat]Chat]

IPCC AR4 Working Group 1: The Physical Science Basis, Figure 4.13

““All glaciers are shrinking.”All glaciers are shrinking.”

A.A. TrueTrue

B.B. FalseFalse

C.C. Can’t tell Can’t tell from this from this graphgraph

IPCC AR4 Working Group 1: The Physical Science Basis, Figure 4.13

Answer: CAnswer: C

We can’t tell We can’t tell if all glaciers if all glaciers are melting are melting because this because this graph is graph is showing us showing us averages for averages for each region. each region. (However, (However, almost all almost all glaciers are glaciers are shrinking.)shrinking.)

IPCC AR4 Working Group 1: The Physical Science Basis, Figure 4.13

““Starting around 1850, average Starting around 1850, average glacier length declined.”glacier length declined.”

A.A. TrueTrue

B.B. FalseFalse

C.C. Can’t tell Can’t tell from this from this graphgraph

IPCC AR4 Working Group 1: The Physical Science Basis, Figure 4.13

Answer: AAnswer: A

This This statement is statement is true and can true and can be deduced be deduced from this from this graph. graph. Glaciers in all Glaciers in all regions have regions have been getting been getting smaller since smaller since the mid-19the mid-19thth Century.Century.

IPCC AR4 Working Group 1: The Physical Science Basis, Figure 4.13

GreenlandGreenland

The map at left shows in The map at left shows in orange/red areas where orange/red areas where there were higher than there were higher than average number of melt average number of melt days in 2007.days in 2007.

There is evidence that There is evidence that both the rate of ice melt both the rate of ice melt and area of ice melt are and area of ice melt are increasing.increasing.

There is evidence that There is evidence that melt water under the ice melt water under the ice is increasing glacier is increasing glacier movement towards movement towards ocean (basal slip).ocean (basal slip).

Antarctica has been losing more than 100 cubic Antarctica has been losing more than 100 cubic kilometers (24 cubic miles) of ice per year since 2002. kilometers (24 cubic miles) of ice per year since 2002.

http://www.nasa.gov/topics/earth/features/20100108_Is_Antarctica_Melting.html

Mountain GlaciersMountain Glaciers

Part of a special section of the NASA’s Global Climate Change Web Site called Part of a special section of the NASA’s Global Climate Change Web Site called “State of Flux, Images of Change”“State of Flux, Images of Change”

http://climate.nasa.gov/stateOfFlux/http://climate.nasa.gov/stateOfFlux/

How Glaciers ChangeHow Glaciers Change

Glacial advance:Glacial advance: Glaciers become Glaciers become larger when more larger when more snow falls than snow falls than melts.melts.

Glacial retreat:Glacial retreat: Glaciers become Glaciers become smaller when smaller when more snow melts more snow melts than falls.than falls.

Activity: Glaciers Then and NowActivity: Glaciers Then and Now

Students compare Students compare photographs of photographs of glaciers to observe glaciers to observe how Alaskan how Alaskan glaciers have glaciers have changed over the changed over the last centurylast century

http://www.windows2universe.org/teacher_resources/teach_glacier.html

Muir GlacierGlacier Bay National Park, Alaska

1941Photos courtesy of NSIDC

Muir GlacierGlacier Bay National Park, Alaska

Photos courtesy of NSIDC

1906Photos courtesy of USGS

Carroll GlacierGlacier Bay National Park, Alaska

Carroll GlacierGlacier Bay National Park, Alaska

Photos courtesy of USGS

Let’s Let’s Pause Two Pause Two Minutes Minutes

for for QuestionsQuestions

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Rising Sea LevelRising Sea Level(with an activity about thermal (with an activity about thermal

expansion)expansion)

How much is sea level rising?How much is sea level rising?

Since 1900 sea level has risen 10-20 cm.(During the previous 3000 years, sea level stayed essentially the same.)

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How much sea level rise is How much sea level rise is predicted?predicted?

Currently, global sea Currently, global sea level is rising about level is rising about 3mm per year.3mm per year.

Sea level is Sea level is expected to rise 18-expected to rise 18-59 cm over the 2159 cm over the 21stst Century. Century.

Why is there a range in estimates? Post your thoughts in the chat.

Web Tour: Exploring the Web Tour: Exploring the NASA Climate Time Machine!NASA Climate Time Machine!

http://climate.nasa.gov/ClimateTimeMachine/climateTimeMachine.cfm

Click on Sea Level

What did you discover?What did you discover?

If the Greenland Ice Sheet melted completely, raising If the Greenland Ice Sheet melted completely, raising sea level 6 meters, which cities labeled in the sea level 6 meters, which cities labeled in the “Climate Time Machine” would be underwater?“Climate Time Machine” would be underwater?

Write your answer above with the text tool.

Why is sea level rising?Why is sea level rising?

Melting glaciers and ice sheets add water to Melting glaciers and ice sheets add water to ocean.ocean.

Sea water expands as it warms.Sea water expands as it warms.http://earthobservatory.nasa.gov/Features/OceanCooling/page5.php

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Activity: Activity: Thermal Expansion and Sea Thermal Expansion and Sea

Level RiseLevel Rise

http://www.windows2universe.org/teacher_resources/teach_thermalexpand.html

With a simple model, With a simple model, students investigate students investigate how thermal expansion how thermal expansion of water can affect sea of water can affect sea level.level.

Students will be able to Students will be able to describe the change in describe the change in water level when the water level when the water is exposed to water is exposed to heat.heat.

Setting up the modelSetting up the model

1.1. Completely fill the Completely fill the flask with very cold flask with very cold waterwater

2.2. Place thermometer Place thermometer and glass tube into the and glass tube into the cork and place cork cork and place cork into the mouth of the into the mouth of the flask. The water should flask. The water should rise a short way up the rise a short way up the glass tube. glass tube.

3.3. Have a student report Have a student report the temperature of the the temperature of the water and mark the water and mark the water level in the glass water level in the glass tube. tube.

Testing what happens as water Testing what happens as water warms:warms:

1.1. Ask students to predict Ask students to predict what will happen to the what will happen to the water level when water level when exposed to heat. Form a exposed to heat. Form a hypothesis or multiple hypothesis or multiple hypotheses. hypotheses.

2.2. Place the flask under a Place the flask under a lamp to warm the water. lamp to warm the water. Within 5-10 minutes the Within 5-10 minutes the water level in the glass water level in the glass tube will have risen. tube will have risen.

Questions Questions about sea about sea level rise?level rise?

Possible Changes to Possible Changes to Ocean CirculationOcean Circulation

What is thermohaline What is thermohaline circulation?circulation?

Large scale pattern of water movement through the world’s ocean basins due to changes in water temperature and salinity, which lead to differences in density.

How likely is this?How likely is this?

http://www.youtube.com/watch?v=3niR_-Kv4SM

http://www.youtube.com/watch?v=lazg1F9hE_c&

Arctic sea ice decline may Arctic sea ice decline may impact ocean circulation.impact ocean circulation.

Decline in Arctic ice Decline in Arctic ice cover 1980 to 2003cover 1980 to 2003

Influx of fresh water Influx of fresh water from melting ice is from melting ice is making Arctic Ocean making Arctic Ocean water less dense.water less dense.

Less dense water may Less dense water may not sink as much as it not sink as much as it does today, disrupting does today, disrupting ocean circulation.ocean circulation.

Questions Questions about about ocean ocean

circulationcirculation??

Ocean AcidificationOcean Acidification

Measurements of atmospheric Measurements of atmospheric CO2CO2

(Keeling Curve)(Keeling Curve)

Image courtesy: www.globalwarmingart.com, See also: www.esrl.noaa.gov/gmd/ccgg/trends/

5/2009386.11

3/1958315.71

Carbon dioxide gets Carbon dioxide gets dissolved in the ocean.dissolved in the ocean.

Up to half the Up to half the carbon dioxide carbon dioxide released from released from burning of fossil burning of fossil fuels gets into the fuels gets into the ocean.ocean.

In ocean water, In ocean water, CO2 forms carbonic CO2 forms carbonic acid which makes it acid which makes it difficult for animals difficult for animals to form CaCO3 to form CaCO3 (limestone) shells. (limestone) shells.

How will ocean How will ocean acidification affect marine acidification affect marine

life?life?

In experiments, doubling In experiments, doubling amount of CO2 dissolved amount of CO2 dissolved in seawater decreased in seawater decreased calcification rates in calcification rates in corals an average of corals an average of 30%. 30%.

Note that the rate at Note that the rate at which corals build their which corals build their skeletons is affected by skeletons is affected by many other factors too many other factors too (such as temperature, (such as temperature, light, and nutrients).light, and nutrients).

Experiment! Experiment! Vinegar + Shell = ?Vinegar + Shell = ?

Vinegar is acidic.Vinegar is acidic.

The shell is made of The shell is made of calcium carbonate.calcium carbonate.

What will happen to What will happen to a shell left in a shell left in vinegar? vinegar?

Write your Write your hypothesis in the hypothesis in the chat.chat.

The shell in the picture is the clam Codakia obicularis, but any clam or snail shell will work. (Shell only! Not alive!)

Results…Results…

Shell in vinegar (left), control shell Shell in vinegar (left), control shell (right)(right)

After 3 hrs – shell in vinegar fragile, color gone, edges crumbling

After 4 hrs – shell in vinegar broken, very thin, crumbling

The ocean is not vinegar. The ocean is not vinegar. (but a little change in pH can make a big (but a little change in pH can make a big

difference)difference)

Vinegar has a pH of about Vinegar has a pH of about 33

The pH of seawater varies The pH of seawater varies between 7 and 8between 7 and 8

Since the start of the Since the start of the Industrial Revolution, pH of Industrial Revolution, pH of seawater has dropped seawater has dropped about 0.1. about 0.1.

In the next century, it is In the next century, it is expected to drop another expected to drop another 0.1-0.35.0.1-0.35. Great Barrier Reef

Courtesy of NASA

Questions Questions about about ocean ocean

acidificatioacidification?n?

Climate and Global Change onClimate and Global Change onWindows to the UniverseWindows to the Universe

http://http://www.windows2universe.orgwww.windows2universe.org

Climate Discovery

A series of online professional development courses for middle and high school educators

CD 501 – Introduction to Climate Change

CD 502 – Earth System Science: A Climate Change Perspective

CD 503 – Understanding Climate Change Today

http://ecourses.ncar.ucar.edu

Join the conversation on Facebook!

Thanks!Thanks!

Lisa GardinerLisa Gardineregardine@ucar.edu egardine@ucar.edu

Thank you to the sponsor of tonight's Web Seminar:

http://learningcenter.nsta.org

http://www.elluminate.com

National Science Teachers AssociationDr. Francis Q. Eberle, Executive Director

Zipporah Miller, Associate Executive Director Conferences and Programs

Al Byers, Assistant Executive Director e-Learning

LIVE INTERACTIVE LEARNING @ YOUR DESKTOP

NSTA Web SeminarsPaul Tingler, Director

Jeff Layman, Technical Coordinator