Modeling Weather Fronts
Lesson 4 of 7
Objective: Students will be able to model how the interaction of air masses can result in changes in weather conditions.
This lesson connects to the following NGSS and Common Core Standards:
MS-ESS2-4 Develop a model to describe the cycling of water through Earth's systems driven by energy from the sun and the force of gravity.
MS-ESS2-5 Collect data to provide evidence for how the motions and complex interactions of air masses results in changes in weather conditions.
CCSS.ELA-LITERACY.RST.6-8.1 Cite specific textual evidence to support analysis of science and technical texts.
Science and Engineering Practices:
Developing and Using Models Develop and/or use a model to generate data to test ideas about phenomena in natural or designed systems, including those representing inputs and outputs, and those at unobservable scales.
Energy and Matter
Flows, Cycles, and Conservation: Tracking energy and matter flows, into, out of, and within systems helps one understand their system’s behavior.
- Matter is conserved because atoms are conserved in physical and chemical processes.
- Within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter.
- Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion).
- The transfer of energy can be tracked as energy flows through a designed or natural system.
I begin every class by asking the students, "What are you going to learn today?". Students respond by referring to the Essential Question, "How can I demonstrate science and engineering literacy?". This EQ is included on their Unit Plan and on the front board.
As the previous lessons in the unit have been designed to help students work towards mastery on the skills in the Unit Plan, I ask students to reevaluate their self assessments from the previous day. Students rank themselves on each of the skills included in the Unit Plan. Students rank themselves on a scale of 1 to 4 (4 being mastery). Students will continue to update these scores over the course of the unit. I emphasize to them that it is ok not to be at a "4". Learning is about growth! We will use this starting point to track the growth in their learning.
Notice in the student work below, that the student updates his scores over the course of the unit as he grows in his level of mastery.
Provide students with time to read the W.2 Weather Fronts Notes Page. As they read, encourage them to talk to the text and mark up their papers with their ideas, thoughts and questions as they read.
In my class, the way that we talk to the text is by climbing the "Ladder of Discourse". The Ladder of Discourse is a strategy I use in my class to help students think critically as they read. For middle school students, informational reading can just become words on a page. The Ladder of Discourse is a way to help students recognize what they should be thinking about as they read so that they can gain an understanding of the text.
The levels of the Ladder of Discourse are "Tweets" (text to self connections), "Huh?'s" (questions or concepts they do not understand), "Found It" (finding answers to questions through context clues or finding science answers), and "Discourse" (combining ideas to think beyond the text). The resource Ladder of Discourse: Description of Rungs provides background about the "rungs" students use when reading.
Review "Key Idea" on the Butting Fronts Lab page. This states that, "Within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter." The movement of water and energy in the atmosphere can determine weather patterns. For example, sudden changes in weather can result when different air masses collide.
Explain to students that they must use the notes/text to develop two models that represent the key idea using the provided materials: jars, food coloring, hot and cold water, laminated note cards (I included laminated cards as a material here because those are accessible in almost any school. However, I actually cut the "lip" off of a plastic gallon size ice cream lid to use and it works much better!). Inform students that they may not actually physically create and use their model until they brainstorm a plan and have the plan reviewed by you. Once students have developed their plan and have it approved, they may carry out their models. Then, students finish by answering the lab questions.
There are a couple of models that students will frequently ask to do that do not quite fit the full requirement of the Key Idea.
1. Students often say that they will warm water on ne side of the tote and cold water on the other side of the tote with the laminated card in between. They explain that they will remove the card and see the boundary. When students suggest this, I explain that one of the key phrases in the idea is that the energy can drive the motion and cycling of matter. I explain that the model that they are proposing will not meet this criteria.
2. This video shows another idea that students often have:
These students have a great idea and have obviously carefully read the text to develop their idea. However, for this model I ask students what type of energy drives the motion of matter in the atmosphere. Students respond with things like "heat energy" or "energy from the sun". I explain that in their proposed model, this thermal energy is not driving the cycling of matter. In this proposed model, their arms are the things driving the motion.
Warm Front Accepted Model:
Watch this video to see one line of questioning you could follow with your students as they complete their models.
Cold Front Model:
You are going to notice in this video how fast this reaction takes place. Sometimes it happens so quickly that it can appear that the colors are just mixing. The video below shows you some questions that you can ask students as they watch their model to ensure they are connecting to the key idea that the cold water is pushing up the warm water. On a side note, as a tip, I find that this model works best with green and yellow rather than red and blue.
The key to these questions is that students take the time to connect to the idea that sudden changes in weather can result when air masses collide. If students simply label the warm and cold water, students are missing the connection that this model has to weather fronts.
In order to complete these questions, students must return to their text to find the types of weather that tend to occur with warm and cold fronts. After viewing the model and reading the text, students hopefully connect to the idea that warm fronts happen more slowly and can last for days where as cold fronts happen quickly and violently.
The key to this question is that in the atmosphere, when warm and cold air masses touch, the boundary between them results in changes in weather. This often happens because warm air rises and cools, resulting in clouds and storms.
Closure: Exit Ticket
Provide the students with the following formative assessment. I sort these slips into stacks of similar learners and meet with conference groups in a future lesson.
When I sort these assessments into groups of similar learners, I tend to find groups of students with the following needs:
1. Students that simply draw a picture of their model. These students recognize that their models were dealing with this idea of weather changes occurring when different air masses collide; however, they have not yet made a clear connection to how their model relates to actual weather phenomena.
2. Students that simply write something like "Warm fronts and cold fronts". Students that write this are connecting the idea of fronts to colliding air masses, which is great. However, simply listing these does not provide actual evidence of changes in weather. The student in the example above states that, "Some evidence is that when you see a violent storm that suddenly goes away that is a result of a cold front where a cold air mass advances on a warm air mass causing warm air to shoot up and cold air to move down causing suddenly violent weather." This is an example of a student that does provide evidence.
3. Students that only provide evidence of one type of front. Students like the students shown above show a great understanding. Even with the student shown above, I would meet and explain that it is always best to provide multiple pieces of evidence when possible. So, his response could have been made stronger by also including evidence of a warm front.