News: Fires in San Diego County

Follow this link to the Sign On San Diego Breaking News page. You will find 3 articles about some fires that occurred in the San Diego area today, Sunday, April 27. The articles are titled "30 acres burned in Sorrento Valley area", "Fire burning in Sorrento Valley", and "Second Ramona fire extinguished."

Read the articles and then post comments about how these fires have the potential to affect global warming? What other effects do fires like these have (effects on the environment and humans/other animals)? How do fires like these relate to recent weather conditions? If you do not live in the San Diego area, use the Internet to research weather conditions in San Diego for this year. You might want to try looking up rainfall amounts.

Reference

San Diego Union-Tribune (2008). Newsblog: the latest news from the Union-Tribune's newsroom. Retrieved April 27, 2008 from http://weblog.signonsandiego.com/news/breaking/index.html

Lab Activity: Acid and pH Levels

Please view the video demonstration of this lab which can be found at the bottom of the post.

This is an easy lab you can do at home with minimal equipment! You will need some litmus paper or pH paper - you can get that at a teacher supply store or through a company who sells science equipment (such as Delta or Nasco).


If you have time, try to gather samples of rain water or pond water from your area.

Use the litmus or pH paper to measure the pH levels of common substances. This could include lemon juice, tap water, vinegar, soda, and liquid soap.

Create a simple chart on a piece of paper to record your results.


Which substances were most acidic? Most basic?

Reference

Spaulding, N.E. & Namowitz, S.N. (2005). Earth science. Evanston, IL: McDougal Littell.

Lab Video Demonstration:

It's Not Just Raining Cats and Dogs Anymore

Acid Rain

Acid rain is the result of a pollutant such as sulfur dioxide or nitrogen oxide reacting with water vapor in the Earth's atmosphere. This can then fall to the Earth as rain or snow (Spaulding & Namowitz, 2005).

As you may know, acidity is measured using a pH scale. Click here to see a pH scale. On the pH scale, substances are labeled with numbers to tell which are more acidic and which are more basic. The lower numbers mean a substance is more acidic. 7 is neutral, neither acidic or basic. Numbers higher than 7 indicate the substance is more basic (Spaulding & Namowitz, 2005).

Normal rain is just a little acidic - it has a pH of 6. This means it is 10 times more acidic than pure water. Scientists have discovered that acid rain that has fallen in the northeastern United States has a pH between 4 and 5. Since the pH scale is ten-fold, this means acid rain with a pH of 5 is 10 times more acidic than regular rain and the pH 4 acid rain is 100 times more acidic than regular rain or 1,000 times more acidic than neutral pure water (Spaulding & Namowitz, 2005).

Acid rain can damage plants and animals. Most life on Earth is pretty fragile and can only survive within a small range on the pH scale. This is the reason why lakes full of fish die due to acid rain. Acid rain also damages forests since it strips the nutrients from the soil. Remember, trees help absorb pollutants and greenhouse gases which lead to global climate change and acid rain. It is a vicious cycle. Acid rain can also eat away at marble and limestone structures (Spaulding & Namowitz, 2005). Check out these sites which will give you more information on the damaging effects of acid rain.

• The Environmental Protection Agency - Acid Rain
• For younger children, here is the EPA Acid Rain Kids' Page
• US Geological Society - What is Acid Rain? Take a look at the map on this page - which areas of the US have the most acidic rain? Why do you think that is? Please post your thoughts in the "Comments" section.
  
• Jump Start Earth Science - Acid Rain. This page has some photos and diagrams you may be interested in viewing.
• The Environmental Protection Agency - Effects of Acid Rain: Materials. This one has a simple lab experiment which demonstrates how acid rain attacks statues and animal bones.
  

References

Decelles, P. (2002). The pH scale. Retrieved April 24, 2008 from http://staff.jccc.net/PDECELL/chemistry/Phscale.html
Science Master (2008). Environmental effects of acid rain. Jump start earth science. Retrieved April 25, 2008 from http://www.sciencemaster.com/jump/earth/acid_rain.php

Spaulding, N.E. & Namowitz, S.N. (2005). Earth science. Evanston, IL: McDougal Littell.

United States Environmental Protection Agency (2008). Acid rain. Retrieved April 25, 2008 from http://www.epa.gov/acidrain/

United States Environmental Protection Agency (n.d.) Acid rain kids' site. Retrieved April 25, 2008 from http://www.epa.gov/acidrain/education/site_kids/index.htm

United States Environmental Protection Agency (2007). Effects of acid rain: materials. Retrieved April 25, 2008 from http://www.epa.gov/acidrain/effects/materials.html

United States Geological Society (1997). What is acid rain? Retrieved April 25, 2008 from http://pubs.usgs.gov/gip/acidrain/2.html

Lab Activity: Temperature Inversion

This activity will show the effects of temperature inversion on pollutants.
If you are a classroom teacher, you could use this lab as a demonstration.
See the video below for an additional demonstration of this lab!

Materials:
1 clear wide-mouthed jar with a lid
1 frozen ice pack (you could also use a sealed bag of ice)
2 sealed zipper bags filled with hot tap water (sandwich size bags)
Duct tape
1 sheet of black paper
1 drinking straw
Matches


Procedure:
1. Tape the black paper to the outside of the jar so that it covers about half of the jar.

2. Place the ice pack on the bottom of the jar and tape the bags of hot water to the mouth of the jar so that the bags hang inside the jar.


3. Cover the jar with the lid and allow the layers of hot and cold air to form inside the jar. This will take about two minutes.


4. Insert the straw into the jar, being careful to keep the lid closed as much as possible. Keep one end of the straw outside the jar.

5. Quickly light two matches, blow them out, and then drop them into the jar through the straw. Observe the smoke from the matches against the jar's black background.

In which part of the jar does the smoke collect or remain? Why do you think this is?
Please submit your answers to the "Comments" section.

Reference

Spaulding, N.E. & Namowitz, S.N. (2005). Earth science. Evanston, IL: McDougal Littell.

Lab Demonstration Video:

It's Getting Harder and Harder to Breathe...

An air pollutant can be defined as an "airborne gas or particle that occurs at a concentration capable of harming humans and/or the environment" (Spaulding & Namowitz, 2005). There are several causes of air pollution including natural causes such as volcanoes. However, it is human activity that creates the pollutants which scientists are most worried about. Modern conveniences such as factories and automobiles spew all kinds of pollutants into the atmosphere. These pollutants can lead to problems such as health problems, acid rain, smog, the depletion of the ozone layer, and global warming (Spaulding & Namowitz, 2005).

The Clean Air Act of 1970 identified the following common air pollutants. Read on to learn about their sources and effects on the environment.

• Carbon monoxide from automobile exhaust. This pollutant reduces the amount of oxygen in the air so it cannot get to body tissues. Carbon monoxide also affects a person's vision and reflexes.
• Nitrogen dioxide from the burning of fossil fuels in power plants and cars. Nitrogen dioxide can irritate lungs. This substance also causes acid rain and smog.
• Sulfur dioxide from the burning of fossil fuels, oil refineries, and volcanoes. Sulfur dioxide irritates the respiratory system and can cause acid rain.
• Particulate matter such as dust, smoke, ash, and soot from factories, paper mills, oil refineries, power plants, and volcanoes. Particulate matter causes respiratory problems and has been linked to certain cancers.
• Lead from smelters and battery plants. Lead can damage the nervous and digestive systems.
• Ozone from the reaction of nitrogen oxides and hydrocarbons in the presence of sunlight. Ozone reduces lung function.

Smog
Remember how I posted earlier about the Industrial Revolution in England and all the air pollution it caused since it led to lots of greenhouse gas emissions? Well, the term "smog" was created to describe the mix of smoke and fog that gathered in the air above London in the early 1900s. This smoke and particulate matter (see above) came from factories (Smaulding & Namowitz, 2005).

Today, what we call "smog" is actually photochemical smog. This smog forms in air that is polluted by automobile exhaust. The nitrogen oxides and hydrocarbons in automobile emissions mix with radiation from the sun and cause the brown haze. This reaction also creates ozone and other harmful pollutants that can damage the environment and our health. The ozone in smog is also harmful to crops. So you aren't confused, the ozone that results from the pollutants that form smog is a powerful lung irritant while the ozone in the stratosphere is helpful to us since it provides a layer of protection from the sun's ultraviolet radiation (Smaulding & Namowitz, 2005).

Temperature inversion can also occur when smog is present. I'll post an interesting lab you can complete in the next blog entry. For now, here is some background information on temperature inversion.
Conditions in the atmosphere cause smog to be more or less severe. What usually happens is that the warm air that hovers near the Earth's surface mixes with the cooler air from higher above the Earth. This helps dilute the pollutants making the smog less severe. However, sometimes the air near the Earth's surface is cooler than the air above so convection does not occur and the air is not able to mix. This is what scientists refer to as temperature inversion. As you may have guessed, this causes more severe smog since the pollutants are not diluted. In this case, the warm air above is a sort of lid that traps the pollutants close to the ground which allows the smog to rise to dangerous levels (Spaulding & Namowitz, 2005).


The photo above shows temperature inversion (Wikipedia, 2005).

References

ClassroomClipart.com (n.d.). Smog clipart. Retrieved April 24, 2008 from http://classroomclipart.com/cgi-bin/kids/imageFolio.cgi?direct=Science/Environment&img=0

Spaulding, N.E. & Namowitz, S.N. (2005). Earth science. Evanston, IL: McDougal Littell.

Wikipedia (2005). Temperature inversion photo. Retrieved April 24, 2008 from http://en.wikipedia.org/wiki/Image:Sha1993_smog_wkpd.jpg

Effects of Global Warming

While most models show that global warming is occurring, and will continue, it is difficult for scientists to predict to what extent as well as to predict the effects. Evidence shows these as possible effects:

• Rising sea levels due to melting polar ice caps.
• Increasing frequency and severity of storms and hurricanes.
• More frequent heat waves and droughts.
• Relocation of major crop-growing areas.

Activity: Now you get to practice thinking like a scientist! As stated above, the precise causes and effects of global warming or climate change still puzzle scientists. Due to this uncertainty, some governments are choosing to reduce emissions of greenhouse gases, while some are resisting action to reduce emissions. What do you think are the benefits of reducing greenhouse gas emissions? What do you think are some risks of not reducing such emissions? Please post your ideas in the "Comments" section.

Reference

Spaulding, N.E. & Namowitz, S.N. (2005). Earth science. Evanston, IL: McDougal Littell.

Lab Activity: Observing Greenhouse Gases

Please be sure to check out the video demonstration of this blog below!

This lab is suitable for high school students.

Objectives for this lab:

• Model the greenhouse effect.
• Graph and compare the effectiveness of different naturally occurring greenhouse gases.

Materials:

• 3 1-quart glass jars
• 3 Celsius thermometers (available at teaching supply stores such as A-Plus or science supply vendors such as Nasco or Delta).
  
• Masking tape
• Marker
• Oven mitts
• Lab apron
• Dry ice (you can often find this at the grocery store)
• Tongs
• Steam (boil some water to get steam)
• Colored pencils
• Graph paper

Background information: The glass windows of a greenhouse allow light and heat from the sun to enter but do not allow infrared radiation to leave. This trapped radiation causes the air in the greenhouse to heat up. The greenhouse effect gets its name because the gases in the Earth's atmosphere are like the windows of the greenhouse. They trap or absorb the infrared radiation from the sun rather than allowing it to escape into space. Some gases are able to absorb more radiation than others and the greenhouse gases are especially good at absorbing it. In this lab, you will have the opportunity to work with three different gases - water vapor, air, and carbon dioxide. In this lab you will compare these gases to find out which one is the most effective greenhouse gas.

**Safety Notes:

• You should always use dry ice in a well-ventilated area. Since this is a lab you will complete at home, it is a good idea to complete this lab outside.
• Wear your apron and have oven mitts ready. Do not handle dry ice with your bare hands.
  

Lab Procedure:

1. Use the masking tape and a marker to label the three jars with the following: Air, Carbon dioxide, and Water vapor.
2. Tape a thermometer to each jar lid so the thermometer's bulb hangs suspended in the jar.
3. Leave the jar labeled Air open for a few moments and then seal the jar.
4. Put on your apron and oven mitts. Wear oven mitts when handling the jars labeled Carbon dioxide and Water vapor.
5. Drop a piece of dry ice (remember, do not touch this with your bare hands) into the jar labeled Carbon dioxide. The dry ice will sublimate (change from a solid to a gas with no liquid phase in between). Once all the dry ice has sublimated, seal the jar.
6. Hold the jar labeled Water vapor upside down over boiling water. Once steam has filled the jar, seal the jar.
7. Once all the jars are sealed, use a copy of the data table shown below to record the starting temperature of each jar.
8. Move the jars into direct sunlight. Record the temperature of each jar every 5 minutes for the next 30 minutes.
9. Move the jars into shade, away from any heat sources, and record the temperature of each jar every 5 minutes for an additional 30 minutes.
10. Use graph paper to graph your results with "Time (minutes)" on the x-axis and "Temperature (C)" on the y-axis. Use a different colored pencil for each jar

Analysis and Conclusions:
Feel free to use the "Comments" section to post your answers to these questions.

1. Which jar heated up the most in the sunlight? Which jar heated up the least?
2. To calculate the rate of cooling, subtract the final temperature from the temperature recorded for each jar just before it was moved into the shade; then divide by the number of minutes the jar cooled (30). Calculate the rate of cooling for each jar. Which jar cooled most quickly? Least quickly? How do these compare with your answers to Question 1?
3. Imagine an ideal greenhouse gas. How would it behave in terms of maximum temperature and rate of cooling? From your answers to Questions 1 and 2, identify the most effective greenhouse gas among the gases you tested.
   
4. Brainstorm ways that humans affect the amount of each gas that you studied in the atmosphere. Try to identify human activities that contribute to the increase of these gases in the atmosphere.
5. Brainstorm ways humans can decrease the amount of the greenhouse gas you identified in Question 3 that is released into the atmosphere.
6. What other gases in the atmosphere can you think of that might influence the greenhouse effect? How common are these gases? How might you collect them in jars for experimentation?
7. Describe what you think Earth might be like if the greenhouse gas did not exist. Describe what you think the Earth would be like if the greenhouse effect were much greater than it is today. Explain your answers.

Visit this website to learn more about greenhouse gases: ClassZone.

Reference:
Spaulding, N.E. and Namowitz, S.N. (2005). Earth Science. Evanston, IL: McDougal Littell.

Video Part 1:



Video Part 2:




Thank you! A huge thank you to my husband for playing "director" and video-taping this lab for us.