Atmospheric variables lesson plan

TITLE:

The ecological effects of adiabatic cooling: Measuring changes in the atmosphere with elevation, and observing the associated changes in vegetation

AUTHOR:

Pacifica Sommers

GOALS:

Measure the change in air pressure, temperature, and humidity with elevation, and observe associated changes in rocks and plants.

LEARNING OBJECTIVES:

Process Skills

• Take repeated measurements of air temperature, pressure, and humidity.
• Identify independent and dependent variables.
• Graph atmospheric changes as a scatterplot.
• Identify rock formations and plant types.
• Contrast visible plant and rock types at varying altitudes.
• Explain why the change in physical factors occurs with elevation, and how that change affects the biological community.

Next Generation Science Standards

3-ESS2-1. Represent data in tables and graphical displays to describe typical weather conditions expected during a particular season.[Clarification Statement: Examples of data could include average temperature, precipitation, and wind direction.]

3-ESS2-2. Obtain and combine information to describe climates in different regions of the world.

MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations. [Clarification Statement: Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems.]

HS-LS2-2. Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales. [Clarification Statement: Examples of mathematical representations include finding the average, determining trends, and using graphical comparisons of multiple sets of data.]

Science and Engineering Practices:

1. Asking questions (for science) and defining problems (for engineering)

• (3-5) specify qualitative relationships
• (6-8) specify relationships between variables, and clarifying arguments and models
• (9-12) formulating, refining, and evaluating empirically testable questions

3. Planning and carrying out investigations

• (6-8) use multiple variables and provide evidence to support explanations
• (9-12) include investigations that provide evidence for and test conceptual, mathematical, physical, and empirical models

4. Analyzing and interpreting data

• (3-5) introduces quantitative approaches to collecting data and conducting multiple trials of qualitative observations. When possible and feasible, digital tools should be used.
• (6-8) extend quantitative analysis to investigations, distinguishing between correlation and causation, and basic statistical techniques of data and error analysis.
• (9-12) introduce more detailed statistical analysis, the comparison of data sets for consistency, and the use of models to generate and analyze data.

5. Using mathematics and computational thinking

• (3-5) extend quantitative measurements to a variety of physical properties and using computation and mathematics to analyze data
• (6-8) identify patterns in large data sets and using mathematical concepts to support explanations and arguments.
• (9-12) use algebraic thinking and analysis, a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms, and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.

6. Constructing explanations (for science) and designing solutions (for engineering)

• (3-5) use evidence in constructing explanations that specify variables that describe and predict phenomena
• (6-8) construct explanations supported by multiple sources of evidence consistent with scientific ideas, principles, and theories
• (9-12) generate explanations that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories

7. Engaging in argument from evidence

• (3-5) critique the scientific explanations proposed by peers by citing relevant evidence about the natural world
• (6-8) construct a convincing argument that supports or refutes claims for explanations about the natural world
• (9-12) use appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about the natural world. Arguments may also come from current scientific or historical episodes in science.

Crosscutting Concepts:

1. Patterns: Observed patterns of forms and events guide organization and classification, and they prompt questions about relationships and the factors that influence them.

2. Cause and effect: Mechanism and explanation. Events have causes, sometimes simple, sometimes multifaceted. A major activity of science is investigating and explaining causal relationships and the mechanisms by which they are mediated. Such mechanisms can then be tested across given contexts and used to predict and explain events in new contexts.

Arizona Science Standards

Grade 6, Strand 1: Inquiry Process (POs are very similar, but more in-depth as the grades progress)

Concept 2: Scientific Testing (Investigating and Modeling)

• PO 4. Perform measurements using appropriate scientific tools (e.g., balances, microscopes, probes, micrometers).
• PO 5. Keep a record of observations, notes, sketches, questions, and ideas using tools such as written and/or computer logs.

Concept 3: Analysis and Conclusions

• PO 1. Analyze data obtained in a scientific investigation to identify trends.
• PO 2. Form a logical argument about a correlation between variables or sequence of events (e.g., construct a cause-and-effect chain that explains a sequence of events).

Concept 4: Communication

• PO 1. Choose an appropriate graphic representation for collected data
• PO 2. Display data collected from a controlled investigation.
• PO 3. Communicate the results of an investigation with appropriate use of qualitative and quantitative information.
• PO 5. Communicate the results and conclusion of the investigation.

INSTRUCTIONAL PROCESS:

PREPARATION

Materials

• Altimeter (1 per group)
• Air thermometer (1 per group)
• Wet/dry bulb thermometer or humidity gauge (1 per group)
• Infrared thermometer (1 per group)
• Plant keys or guide (1 per group)
• Rock and mineral guide (1 per group)
• Each student needs pages 4-10 of the journal covering hypothesis forming about the changes with elevation, data table, graph axes, and follow up questions.

Setup

• Have equipment available to each group, and journals for each student.

INTRODUCTION/ENGAGEMENT:

Essential questions

• How is climate different from weather?
• What are the relationships between air pressure, temperature, and humidity?
• How do physical factors affect organisms and biological communities?

Student misconceptions

• Air pressure increases with elevation
• Humidity increases with elevation

Learning structure

• Students split into groups of four, each one led by a Sky School instructor.
• Each student is responsible for recording and graphing his or her own data, but teams work together to use take measurements.

EXPLORATION

Step-by-step description

• Begin by asking students what they expect to change (or have observed changing on past trips up the mountain) with elevation. Many know there are pine trees instead of cactus, and that it is colder up there. But they do not know why.
• Ask students to hypothesize why the summit of Mt. Lemmon will be colder than the base. Depending on their age and knowledge, you may give them hints about other factors it depends on. If students already report that lower air pressure will cause cooling and they can explain why, focus instead on whether that makes the air hold more or less moisture, and whether that leads to more or less rain at the summit.
• After discussing hypotheses, choose variables to focus on measuring. Suggest the group measure a few additional variables as well, since many field scientists will take measurements or at least notes about additional factors in case something else turns out to be important. These include things like the hottest and coldest microclimates at each site, since animals and plants might respond to their immediate surroundings more than the average air temperature.
• Provide equipment to your group to take these measurements, and perform the first set of observations. Compare notes with other groups, then proceed to the next two stops to take repeat measurements. Have students rotate who takes each measurement at different sites so everyone gets a turn, but emphasize the importance of standardizing their methods – taking air temperature in the shade, held far away from their body heat, for example. Engage with students to discuss the trends they see at each site: has humidity changed yet? Is it going up or down? Is that what they expected?
• After the fourth set of measurements, ask students to revisit their original hypotheses. Why did they think it would be colder – was it related to an increase or a decrease in pressure? Ask them to plot this data on the axes provided in their journal, then draw conclusions about whether or not it supports their hypotheses, supported by their evidence. Discuss their conclusions, and additional data or relationships that might clarify the picture. Ask students to contrast the biological community at the different stops, and ask whether the physical factors that also changed corresponded with biological shifts.

APPLICATION

Why does it matter?

• This explains the change in vegetation students are observing between Tucson and the summit of Mt. Lemmon. It provides students a basis on which to predict what organisms to expect when traveling to other places based on climate.

• These questions connect several disciplines that are thought of as separate.

Extensions and/or follow-up activities

• Especially for a high school audience, pool across-group measurements of some factor (e.g. % plant cover) at each elevation, then make a boxplot of that factor vs. elevation, to see if the variable changes more across elevations than across student groups. If it does, then students can evaluate the evidence for climate affecting that variable, or at least some other variable affecting both climate and that variable. This provides an opportunity to teach about mean, standard deviation, best-fit lines, and causation vs. correlation.

• Also a good inquiry project to jump off of this lesson (following on 'Ask students to contrast the biological community') is to see if there are any functional or morphological aspects of the species that are consistent within or across sites. For example, more succulent plants may exist at low elevation while more top predators (bears, sasquatch) might exist at higher elevation. This can be good brainstorming to synthesize observations and lead to a range of extra hypotheses.

ASSESSMENT

How will you determine if students “got it”?

• Students will successfully take measurements of study variables and record them in the data table of their journals.
• Students will successfully point out and name several plant types and rock types.
• Students will successfully create a scatterplot of at least one pairs of the physical factors, and interpret * their graph to conclude how physical factors changed.
• Students will hypothesize what causes those atmospheric variables to change the way they did.
• Students will hypothesize how the changes in the observed biological community relate to the physical conditions.

RESOURCES

List any websites, texts, or journals to help others better understand the material in order to teach it

• Google imaging “adiabatic cooling” and “mountains” will give you an intuitive idea of the general idea.
• Before the trip, classes can watch the 9 minute video “Introduction to Arizona’s Sky Islands” at http://www.youtube.com/watch?v=TTzFM9KEfHE