Teaching About Hurricanes

John van Vlaanderen, September 18, 2006

Oblique Investigation: Two directions

Initiating learning from hurricane experiences, and careful consideration for trauma

Students already have knowledge of hurricanes, but the knowledge may be based on the ferocity of hurricanes; it is very likely that the knowledge is linked to trauma if the children live, or have lived, in areas where hurricane weather occurs frequently. TheyI studying we will bring with them to class their experiences, and may very likely want to express them. Encouraging children from these types of areas to write journals and create artwork provides them with a reflective outlet for feelings and ideas that they have; teachers can use creations to access the state of the class with respect to trauma.

Their experiences will make them curious about weather, and their reflections of their experiences to the class will help create a teachable moment. Teachers can use this opportunity to teach about weather in a way that involves the students’ experiences in their learning, and helps create knowledge they can use to resolve feelings they have about the devastation wrought by hurricanes.

Since the knowledge may be associated with trauma, the students’ reflection of their experiences needs to happen as an unhurried and voluntary flow. Students may relate their memories to the class, or they may choose to confide in the teacher. There is very little a teacher, or anyone else, can do to directly heal the effects of trauma. In cases where their experiences have been traumatic enough to cause anguish and personal pain, solutions obviously lies outside the class with healing professionals; extreme suffering usually requires anti-depressant medication to prevent damage from the resurgence of the memories.

The reflection of the trauma process is necessary; the idea that the trauma can be separated from the student while the student is sitting in the class, and therefore ignored, is the thinking of purely detached teachers attempting to side-step responsibilities. The types of expressions teachers are famous for initiating, are the beginnings of group involvement and community; they are a basis of what we appreciate as the human experience: its suffering and joys.

The oblique approach to teaching about hurricanes, and resolving hurricane trauma issues, involves a study of weather from a typical earth-science approach. As the topics become sophisticated, concepts can connect to allow students to begin to form a picture of how weather systems interrelate to create the ferocious that cause so much hardship.

As students initially reflect their experiences, teachers, in a parallel process, can begin to create plans for study. Noting expressions in student journals and art is important in helping teachers can know if students are going to experience trauma symptoms; it is important to try to predict the trauma resurgence known as flashbacks. There can be an implosion of memories that is, in itself, highly damaging.

An important responsibility lesson for students is introduced when they learn about the realities extreme weather. The responsibility they learn is about self-preservation in the context of the hurricane; they become self-determinant with respect to their lives. The focus of the learning is on responsibility (and science) in relation to life. Students can also learn about areas of study that they may want to pursue as careers through the diverse learning associated with studying about hurricanes.

The concepts that the students present, in their reflections of weather, can be valuable clues to help teachers create experiments to initiate the studies: the basis of the understanding of weather by children can lead to community acceptance of the reality of hurricanes.

Because of the scope of weather studies, it seems unlikely that students will introduce the concepts that can be used to directly approach the central concept of weather: that all weather is affected by other weather, by other elements of the physical nature of the Earth, and even by things in space.

Likewise, the traumatic nature of hurricane studies requires that the study process be scaffolded to prevent too many realities from being presented simultaneously. In the classical sense of scaffolding, students have to be shielded, somewhat, from the central issues. Yet, they need to begin to start knowledge building skills of webbing, really concept building, to be able to eventually tackle weather concepts from a holistic, or general systems theory, approach. In their study of weather will be much conceptual grasping and required learning. Physics and math are essential for weather learning.

Social and personal perspectives will eventually be addressed especially if the community is involved. How things will play out for the students personally, and for the community as a whole, will become questions that possibly lead to independent and relevant inquiry and project oriented resolutions on the community level.

Certainly, the best-known hurricane experience, the Katrina disaster, will become a topic at the community level if the community is invited into the learning process. Teacher preparedness to field these issues, by channeling them in a proactive direction, can prevent dissolution into conceptual disorder triggered by the traumatic nature of hurricanes and experiences with their aftermath. Teachers may want to introduce questions into the general study at relevant points if certain concepts don't come up naturally as part of a long-term inquiry and study.

Knowledge Organization

· Webbing: Students create webs with their personal concepts of weather

· Computers: Introduce web searching, email, keeping notes, using word-processing, creating web pages.

· Group Organization: Show students how to create work stations to experiment with their concepts, allow groups to form as students gravitate towards interests

· Class Work: Observe the workgroups, re-form workgroups to diversify interests and talents, note inquiry to create mini-projects by designing experiments, explore mini-conceptualization

· Individual Work: Identify solo learners and self starters, find community mentors and experiments from long term study plan

· Concept mapping: Introduce the structural ideas behind concept mapping--complex structures. Discuss the nature of concept maps; use the discussion as a continual re-grouping space to tie the projects into a single weather system understanding.

Initiating the Project Cycle (First concepts - child science)

· An Experiment: Rain experiment

· Development of First Experiments: Creating rain

· Developing as Scientific Fact: Measurements in rain experiment

· Solidifying the Learning: Building concept maps

Allowing ideas by the children, and young students, to guide initial experimentation is never wrong, no matter how childish their ideas seem. There are no wrong answers by students in their initial inquiry phases because they are applying inquiry to the world as they see it. Rather thinking of them as being wrong, think of their ideas as "intelligently wrong." (Ault from Shapiro, p 21) In developing ideas and presenting them, students have taken an important step: they are taking responsibility for their learning.

Knowledge organization consists of skills; exciting progress has occurred in the advancement of these skills in the past two decades to help students successfully, quickly, and enthusiastically build knowledge. This is in the area of webbing, or the concept maps, and in computers. The seemingly new ideas brought to the class by the constructivists are also helping students build knowledge, but they are, in reality, a revival of traditional community values. Today, in Canada, the Aboriginal Television Channel every day has programs where modern Native philosophers discuss tribal community relationships and traditional therapies that would seem radical even for constructivists and Humanists.

Completely new to our generation, I believe, is the concept map. Teaching concept mapping, group dynamics, and rudimentary research techniques--teaching to learn through project science--might require a didactic class in the beginning to introduce knowledge organizational techniques, concept mapping software, and also mind mapping software. If using computer technology, an introduction to the structural ideas behind the concept maps, complex structures may also be helpful. The use of concept maps can be a continual re-grouping space to tie the projects into a single weather systems understanding.

Combining the initiation process of the learning cycle while introducing rudimentary knowledge organization skills may provide a chicken-and-egg conundrum. It would be conceptually perfect to allow students, as their first weather experience, latitude to use their natural curiosity along with guidance to provide them with some sort of ground shaking epiphany (from a child's perspective) to initiate their learning. But, so important are the organizational skills and responsibilities for group learning, that it seems necessary to provide an instructional introduction to assure that disruptive behaviors and other tendencies that may undermine group learning don't redirect the learning process to the point that the teacher is spending more time correcting behaviors than guiding inquiry.

Ideally, students should become curious about weather, auto-magically picking the topics on which to test their conceptual understandings, coming to the correct conclusions and inserting their new knowledge into their knowledge trees. With practice, this will likely happen, especially if the students are introduced to knowledge organization at the early stages, say kindergarten or the early grades. More likely, however, the teacher will have to provide guidance. She may have to start with an obvious example, creating an experiment, recording information and, with all the learning, create a concept map.

Many students succeed within the classic scientific corollary of observation, hypothesizing, and experimentation; many older middle school students have stronger abilities than most adults have in the classical scientific methodology. A middle school student created a web page showing a correlation between clouds and temperature, which, at least for the conditions during the study, proved her hypothesis that clouds make the temperature cooler. (Erika)

A good percentage of students will study science at home individually or in pairs. They individually will wonder conceptually in ways that need to be initiated in classes; their inquiry can be naturally self-guided. Their work will very likely be perfect contributions for the class knowledge structure. Sadly, in today's society, their work may go unnoticed, may be deliberately ignored, or may even be discouraged. In Bonnie Shapiro's experience, fully half of her study group worked at home, yet the teacher was unaware of their work. In particular, two, Melody and Pierre, implemented aesthetic concepts into their scientific learning in ways society has yet to integrate, by appreciating nature as approaching science, and by illustrating science learning in the ways Darwin did. (Shapiro, 152)

Teachers need to carefully empower the student group with a positive and inclusive learning environment to draw every student towards scientifically valid concepts, both factual building blocks as well as social constructs. Many students may come to school already having been exposed to disruptive or controlling behaviors, the types experienced in highly competitive or abusive family environments, or even in prisons.

The simplest weather experiment, probably, is creating rain in a glass jar. If the lid of a jar has attachments to the inside of it so that vapor can condense and drip, water can be heated at the bottom to be vapor, and condensed with cold at the top, by putting ice on the lid, to show that rain is cyclically evaporated and condensed water. A concept map, or web, for this construct can be created on paper or with magnetized cards connected with lines drawn on the board. Measurements may be applied to demonstrate the conservation of matter through the process, introducing some required learning. Concept mapping techniques can be applied to the idea of a closed system without any difficult constructs to complicate early learning. Students bored by the simplicity of the experiment can be encouraged to design more complicated experiment designs; students bored by the simple social construct can be invited to develop better concept maps or facilitate a group learning structure.

Constructs develop first on paper; then they go to the board. As students become familiar with computers, they can start building the concept tree. Misconceptions start giving way to group learning, as student working in groups tend to eliminate resistance to accepted scientific ideas simply by developing consensus through their experiments. In some teaching environments that have used group project science for decades, misconceptions may not even exist, because a culture of scientific discovery has been developed in the student community; their community science is scientifically based. Even through schoolyard play, the youthful community may have already implemented knowledge construction as a component of their culture. (White)

Ideas flowing into the concept map have to be accepted as established science at the top level of the map construct, so that the map is valid in its basic premise. While the discovery of non-valid ideas within the root ideas (or nodes) of the concept map may be a valuable lesson in correcting misconceptions, building knowledge based on fundamental misconceptions introduced by students (and permitted by teachers to allow students to correct their own misconceptions), may also be a huge waste of time and resources.

Maps develop over a long period so that the basic concepts can be accepted as fact throughout the community. The mapping process has to be sophisticated so that idea constructions can be shared with other weather learners, and published so that the community can give recognition. Storage and access are important too so that the students can continually build and reference their information. It is probable that existing mapping tools do not yet meet these needs. Students may have to develop their own concept sharing skills, something entirely doable at the high school level, in my experience.

Making weather learning sophisticated

Wind, rain and clouds are obvious components of weather and storms; they can work towards the study hurricanes (without mentioning it by name yet), students can easily identify rain and wind as ingredients of a storm.

Understanding where rain comes from, and how it relates to clouds, offers plenty of challenge to students. Interesting are the related ideas of the water cycle, how water evaporates from water bodies (such as oceans), forms into clouds to return to Earth (and oceans) as rain. Initially, many students associate clouds, along with thunder and lightening, with God. Sometimes they think clouds are man-made and that they are smoke. As they learn the idea of change-of-state where water vaporizes forming clouds and the water returns to earth as condensation. Here they can explore many ideas, especially understanding that air is matter; initially children only assume that solids are matter. (Henriques) They usually believe water turns into air as it vaporizes, which is technically correct, but they can enhance that evaporation concept by knowing that water vapor molecules combines with all the other invisible molecules that make up air. A demonstration of the water cycle can be constructed within a closed aquarium. One half of the aquarium has a pool in it with a heat source such as an over head lamp. The other half has cooling applied to the cover so that the water vaporized by the heat source will condense and fall back on to the aquarium floor. A miniature mountain range with valleys can add aesthetics to the learning.

(University Program for Atmospheric Research)

As they become expert in understanding the water cycle, students will realize that water vapor is clear and colorless, yet becomes white when it forms clouds; they then understand clouds are really made from tiny water droplets, just as fog is. Fog can be created with an ultrasonic humidifier; it can be poured into a pitcher and dumped over a model town for effect. Clearly, fog sinks with gravity; water droplets are heavier than air, which will explain rain. But, why do clouds stay aloft? One obvious reason is that updrafts of air push the vapor up, but what holds the masses of droplets there? Water when it vaporizes absorbs heat at its source, when it condenses it releases heat to the surrounding air. The combined air and water droplet suspension maintains the same warmth (or heat) it had when it rose as air and water vapor from its water source. As a difficult concept to absorb, this learning may have to wait to become a completely formed idea in the weather concept map.

Introduction of the water cycle, along with the concept that air has matter and is a combination of things helps bring students closer towards the idea of weather as the interactive system: the holistic (or general systems) approach to science. The idea of air as being matter extends the study of air to the study of wind; if air has mass, moving air, or wind, has force. The idea that air can exert static pressure has to wait; it is not until later middle school that static force can be absorbed. Understanding the static force of air is essential, because of the barometric components of weather formation and measurement. With all these steps, students move towards becoming experts in hurricane understanding.

While students can develop basic components, such as wind, rain, and the clouds; other ideas such as the relationships between these, require teacher prompting. Truly sophisticated ideas such as the water cycle need more teacher guidance. Having been prompted and guided, the learners can discover and experiment until they get stumped. When perplexed, they may accept scientific explanations as holdovers to satisfy them until they can provide their own proofs. The more scientific ideas students can accept, the more quickly they can move on, allowing more sophisticated learning to challenge them. Interactions between groups from different grades may allow more expert students to help younger students clear out some of the less accurate of the intuitive understandings they brought to school.

Crucial for students is the ability to create science they can embrace, so that they may be the initiators of their own experiments, or the owners of the research information they synthesize from valid research material they have collected. They can return to their group, with its accumulated weather knowledge, to find areas that perplex them, necessitating clarification. They can contribute individually or in small groups, gaining from the group confidence, returning an air of credibility and expertness to the group as a whole. Wide-ranging understandings utilizing science is a social atmosphere can help the group weather all kinds of challenges, not just the extreme weather they have, or may, in the future, experience.

It is unlikely that students will initiate inquiry into the larger weather system concepts, because, as systems, they are dependent on so many contributing factors. They may be able to initiate inquiry about the smaller concepts, creating mini-projects from the greater concepts (there is no shame in mini-learning as weather as it is represented in the concept map is a construction of mini-systems.) Group success, from the perspective of the concept map, is in finding mini-learning so as to be able to take ownership of successful inquiry; hence the insertion of valid concepts in the groups accumulated knowledge. For group inclusion, it would be necessary for every student to have their name on at least one successful inquiry; it may be necessary for the teacher to supply inquiries to those students unable to initiate their own inquiry by finding things they cannot understand in the greater learning. It may be also necessary for teachers to assist in the resolution of inquiries to assure that students have work they can be proud of, to give them confidence to initiate new inquiry. None-the-less, these inquiries, or mini-projects, have to be studies comprehensive enough to all the available talent in the group, there needs to be a slight “division of labor” to assure that everybody is doing tasks they can enjoy and succeed at.

Knowledge development cycles

As the general understanding of weather becomes more comprehensive, individual understandings become smaller in comparison to the big picture. Cycles of inquiry and concept development become shorter as the students become more expert at weather studies and their knowledge organization skills improve. Group effectiveness is also important as students become more involved and responsible, and the more confident students learn how to encourage the less confidant students to be more productive, giving them the boost they need to succeed.

Truly successful projects in all science fall into development cycles. A good point of evaluation for a project is when a component of the project, or the whole project, is delivered or presented. For science project learners, this would be when a significant understanding is contributed to the concept map. An interesting point for inserting required math learning is when students evaluate their successes in knowledge creation. In a sense, failure can be avoided by allowing students to re-initiate their mini-projects so as to be able to reinforce their learning, as well as produce results worthy of recognition. If students can repeat their learning in cycles, ultimately achieving complete success, their evaluation benchmarks can be very strict: the kind of evaluation criteria scientists use. Generally referred to as milestones, quantifying progress in cycles may be an opportunity to introduce embedded required math learning as part of progress analysis. Graphs, for instance, can be introduced to allow students to show levels of improvement; Concepts of statistics can be introduced to help them understand their rates of growth. They will be very interested in measuring their success because their studies are so significant in their lives.

A contributing text about teaching standards by Firestone, Schoor and Monfils provides an excellent scenario where a teacher encourages inquiry in the statistical analysis field by handing out M&Ms. She asked students to discover trends in the occurrences of candies of different colors. The teacher gave each student a bag of M&Ms and had them create graphs showing the numbers of each color of candy in the bags; one student was able to extend the idea to developing mean values, so the teacher extended this boy’s concept to explain statistical basics. She gave the students opportunity to develop their own scientific learning, and of course, not lost on the students is a tasty reward for participating in the learning. (Firestone, Schoor, Monfils, 1) Breaking learning into bite-sized tasks makes them more consumable, but learning is best achieved in the context of relevant meanings; such as when they develop criteria for their own success.

Measuring mini-projects for success at the arrival of each milestone essentially seeks to find what level the inquiry has satisfied scientific needs to be a valid component of the accumulated knowledge, or the knowledge tree. Sometimes an inquiry will be too difficult for the students who are younger. Other times direct experimentation may have to yield to researched knowledge: teachers will have to use their discretion in amending the evaluation process to assure that students remain confident and enthusiastic; success from the inquiry perspective is always achievable with future mini-projects, or at future milestones.

Individual mentoring, community learning

While the concept where human capital is created by separating students into groups by ability has no place in project science, there is the reality that many, if not most, students will not graduate from college. For them, the community is their place; many will likely settle into trades work sooner than college-bound students will take professional positions. They may have already settled into a trades future, and they are waiting to graduate from high school. Or, they may just leave school to start working. For them, education may work best in community mentoring environments; they need to develop science that they can take to the workplace; they need to have an interest in science as, historically, science and math have been the process by which their futures have been limited. Science and math have deliberately used to create controlled diversity in the supply of human capital--cheapened humans. Students thus affected are not unaware of this; they just unable to counter act it. (Roberts, Ostman, Leif, 175) To help them implement science and math in their lives and workplaces, weather instrumentation is perfect learning; it combines trades skills with understanding and accuracy. Along with gaining recognition in the learning community, they can experience recognition in the trades community which they may soon join. Economic desperation (thought of as low Synergy), with accompanying dishonesty, has resulted in repressed local economies in every nation; science in the community can contribute ideas of honesty with the introduction of scientific accuracy as part of developing scientific knowledge. As mentoring projects progress from early inquiry stages to expertness, the instruments themselves, and the data collected may make the community teams valid parts of the greater scientific community; satisfying a community requirement from education: a connection with science.

In an apprenticeship environment, there should be no separation from the groups working in the schools. The embedded required learning, especially with respect to math skills, needs to be evaluated at milestones; the apprenticeship projects are experimental and scientific in purpose. These projects can be initiated with the confidence that many scientific concepts will be introduced to the community from the school, the ideas of responsibility and the further discussion about the social and political realities of hurricanes will go a long way to flow conceptual understandings into the community. Interests in life-long learning by families and the community will encourage attendance in community colleges.

Encapsulating scientific learning into mini-experiments is part of building instrumentation. Mentors, if chosen from workforce, may want to create tools most efficiently, accidentally excluding student discovery from process. In these cases, limited budgets may actually be beneficial, by encouraging resourcefulness on the part of students to create components from cheaply available materials. Students can take further ownership of projects by utilizing the web to get information about building projects.

As instruments become sophisticated, as students rise from novice to expert, instruments may become part of a network for collecting weather data. In Britain, Royal Meteorological Society scientists network with schools (BBC Weather); amateur networking through Internet very likely already exists. There are socially organized rescue organizations, especially ham radio clubs, who may be interested in networking with schools. Still, student projects need to remain focused on inquiry, and continually need to return to the development of concept maps to assure the efficacy of group learning; educators have to structure all the mini-projects around the cyclic development process.

Because learning to learn is the goal, mentors have to be open to student discovery; they have to be patient with younger learners. Very likely, mentors, especially if they are retired educators, may assist in supplying initiating inquiry ideas, and may already have scaffolding experience to help less confident learners.

Weather instrumentation

Creating scientific instruments as part of inquiry from available materials, rather than purchasing them at significant cost, will create enthusiasm among fiscal leaders. There is a surplus of old schools created by the centralization of school systems by school boards; they can be utilized, filled with experimentation equipment, both for measuring weather and exploring other natural sciences. Local communities already own these structures; abandoned shopping malls are also legally available to communities; abandoned generally have huge ceilings, available power, adequate ventilation, strong floors, and parking.

Alternative learning occurs in libraries, museums, at home in home schooling. (Falk, p 171) Here, ownership and self-reliance and fiscal responsibility can combine with community ownership as existing structures can be revitalized to be a combination of alternative learning locations with greater community access at far less expense than museums and libraries, if volunteer mentors are utilized. Community self-reliance, fiscal responsibility, and activities for kids (and by kids) are benefits to the community which will be recognized by the community, giving mentors the social status of expert. Once again, existing top-down organizations have to be avoided; the focus needs to be on the students and their projects rather than the organizational needs of local clubs. The ownership must belong to the project groups; the potential for the expansion of social control may be too much of a temptation for existing community groups, they may attempt to hijack the process for their own social control purposes. In project science, as with all education, the student is the boss; students have "full veto power," and they have the ability to create and destroy science; it is, after all, their education. (Polman, 135) They must be given every opportunity to understand the benefits of science education and be shown that the benefits will help them immensely in their lives.

The science of hurricanes

At some point, it will become apparent to students that hurricanes are the focus topic; they will become aware of the importance of understanding hurricanes. This will very likely happen at a point when they can, probably as a group, psychologically accept the levels of hurricane ferocity and the nature of hurricane destruction. The teachers and community may need time to acclimate to the ideas; but the acceptance of the reality of hurricanes is necessary to a community that may experience full-on weather.

Technically defined: hurricanes are "cyclones of tropical origin with wind speeds of at least 118 kilometers per hour; they are large, rotating storm, where the winds move around a relatively calm center called the ‘eye’." Each storm usually has a life span of several days." (Canadian Hurricane Center) The hurricane season, the period most likely to experience hurricanes, is from June to November in North America; in the North Atlantic, it is September.

Hurricanes, like all storms, are born of low pressure; air rushes to a low-pressure area, to even the pressure. Usually low-pressure areas are warm and, therefore, create updrafts. Over the ocean, warm water also warms the air above it, adding to the updrafts. When the mass of raising warm air reaches heights with significantly lower pressures, the air expands lowering the temperature. The water vapor in the air changes state; the air mass becomes supersaturated with cooler water molecules as in fog, or breath on a cold day. Collisions between the suspended water molecules in the supersaturated air mass joins them to form droplets. The water molecules scatter sunlight (and moonlight) giving these newly formed clouds their whitish appearance. Also, tiny particles in the atmosphere, such as dust and smoke, are attractive to water molecules; the combining of water and particles in the clouds helps initiate the droplet forming process. If clouds become very cold, the water vapor changes state to ice rather than water; rather than forming as raindrops, the molecules become ice crystals to be turned into rain drops as they fall to altitudes with warmer temperatures where they melt. As droplets get heavy by colliding and combining, gravity pulls them to earth, creating turbulence in the surrounding air, causing more water molecules to collide forming droplets. The water vapor molecules, when they form droplets, release the warmth they absorbed when they evaporated from the ocean surface. As the droplets fall by force of gravity, the remaining air mass rises with the heat left by the condensed and now descending water molecules. The rising of the remaining air creates powerful updrafts, increasing the size of the clouds, pulling up more water from the ocean surface in the form of vapor. Water molecules may change state between liquid, gas, and ice many times depending on the wind activity and differing conditions within in the clouds before the molecules become heavy enough to fall to the Earth. The air molecules that surrounded the water in the fog-like cloud suspension now have the warmth that was released by the condensing water vapor, as well as the original warmth from the warm ocean from where the water first evaporated. As water droplets fall, the remaining air, still a suspension of water and gaseous air, rises. The rising air develops into powerful updrafts of wind.

Ingredients needed for a Hurricane

· Warm waters

· Air cools as you go higher

· Wind must be blowing in the same direction from 0 to 9,000 meters up

· Must be 500 Km away from the equator, to start spinning

Hurricane forming: http://www.msnbc.com/news/wld/graphics/hurricane_dw.htm (Frost)

Creating hurricane conditions: http://www.nhc.noaa.gov/HAW2/pdf/canelab.htm (NOAA)

Hurricane building strength: http://www.nasa.gov/mov/49983main_cloud.mov (Chohan)

When conditions are right to create huge updrafts of air, the spinning of the earth has the effect of starting a swirl in the clouds; this is called the Coriolis effect. As increasing amounts of warmth are added to this swirling cloud mass, a tropical storm is born; in many places they are called cyclones. If conditions are just right, the storm will absorb increasing amounts of water. Meteorologists say the storm pumps water into itself, adding to its size and power. Only a journey north to cooler waters, or a landfall, cutting off the water supply, can slow the storm building process when a tropical storm reaches hurricane levels. Rising air moves outward from the top of the hurricane to make the whorl of clouds that can extend for hundreds of miles.

Coriolis force: Objects are deflected to one side because of the Earth's rotation. The object is going straight, but the Earth moves beneath it, making it move to one side. In the Northern Hemisphere, the Coriolis force deflects objects to the right. Sending a ball rolling on a spinning merry-go-ground will demonstrate this deflection.

Coriolis demonstration: http://archive.ncsa.uiuc.edu/Cyberia/DVE/coriolis/coriolis.mov

At, or very near, the center of the hurricane is the eye. When the eye of a hurricane passes over a region the winds decrease to just a gentle breeze, is surprisingly calm and the rain stops. Someone standing in the eye may even be able to see the sun during the day or the stars at night. The eye wall is the area surrounding the eye; the heaviest rain, strongest winds and worst turbulence are normally within the eye wall. At the center of the storm, the eye is the lowest pressure area; the low pressure pulls water upward, forming of slight dome of water under the eye. This rise of water combines with other effects to create the storm surges that create floods when the storm reaches land. Waves of ocean water converge under the eye creating even worse conditions for boats.

Creating a hurricane eye: Students can observe spiraling in the tub, when they open the drain. There are significant differences between a hurricane's spinning and the whirlpool created by the water; in a hurricane the motion is upward, not down the drain, and that the Coriolis force is far less significant in this experiment; most likely, physical features of the tub will determine spin direction. Also, a fun experiment is to fill a plastic bottle with water and insert the mouth of it into an empty bottle with a slightly larger mouth. As the water transfers between bottles, dramatic spinning is created. Physically, the spinning more resembles a waterspout, which is only a distant cousin of a hurricane, waterspouts; a waterspout is the offshore sibling of the tornado. Vorticity is the term for the measure of local rotation in a fluid flow: the spin of a fluid.

As almost a joke, there are safe and unsafe halves of hurricanes: navigable, and unnavigable. When I was a young sailor, I was voyaging with a seasoned crew on a big schooner. We experienced Agnes, a then famous hurricane that traveled unusually far north--fortunately we were ashore at the time and the boat was safely docked at the traditional sailing fishermen's haven of Point Judith, Rhode Island. Being safe, we chuckled about the safe and unsafe terminology for hurricane sections. Since hurricanes can move in a linear direction as fast as, say school buses, and since they spin much faster, often at the speed, of a small plane, half the hurricane (at a point normal, or perpendicular, to the directional path) will likely have an effective speed of an airplane minus the speed of a school bus. Likewise, the other half, the unsafe half, may experience a speed of the airplane plus the school bus (at its respective normal point). More commonly, the worst part of a hurricane is referred as the right front quadrant (RFQ), especially in relation to landfalls.

Hurricanes weaken and die as they lose their source of warmth from the ocean, along with needed water vapor. Hurricanes suffer a quicker death over land, starved for vapor; or slowly as the move north into the mid-latitudes, more from heat loss. The size of the circulation usually expands the speed of the maximum wind decreases, and the distribution of winds, rainfall, and temperatures become more homogenous.

Wind

Wind is produced by heat and pressure. A part of the atmosphere that has lower pressure will suck in air molecules with force that creates wind. The Earth's surface, made of land and water, gets heated unevenly by the Sun. Sometimes this is because of the angle of the Sun with respect to latitude, the cause of seasonal change; sometimes it is because of the nature of the surface of the Earth. Differing temperatures cause air to rise and fall. As air masses travel as a result of pressures and temperature around the world, they form predictable currents of air.

Students can measure wind much as scientists do. With small paper cups (3 or 4), straws for arms, and base with a low friction support, such as a pin, an anemometer can be build quickly and cheaply. The speed of the anemometer will be proportional to the speed of the wind; students can easily see that different rotational speeds relate to different wind speeds.

The wind speed can be estimated with simple geometry, if the students can count the number of rotations of the spinning section to determine the RPM. They would also have to measure the width of the spinner and calculate its circumference, and with that determine the speed of the motions of the cups.

Direction is also important to measuring wind; students can easily build a compass the way the early navigators did using a magnetized needle resting on a light object floating in water.

To further sophisticate the anemometer, a very small direct current generator might be constructed by attaching fragments of super magnets to the spinner and measuring flux in the field it creates as it moves. This would bring the experiment instrumentation closer to expert level; drawing in other disciplines along with them more required learning.

My experience with Hurricane Agnes, as a child, was that the wind was coming from everywhere. Clearly I was experiencing turbulence. Within the observation of turbulence is much gaseous molecular study.

Creating Clouds

A sophisticated cloud experiment involving the pressure, temperature and particulate contributors to cloud formation can be done easily. One way is to fill a 2-liter bottle one-third full of warm water and drop a lit match into the bottle. By squeezing the bottle, increasing the internal pressure, cloud material will appear inside the bottle. Decreasing the pressure will cause the cloud to disappear. Another, more controllable version of the same experiment would use a much larger stiff container and a rubber cover such as a stretched latex glove.

(Crozier)

Measuring Humidity

Students can easily build a sophisticated psychrometer, though its functionality may elude them.

In such a project, two thermometers are taped to a surface where one has wet gauze tied to its reservoir end. A fan blows on the thermometers until the temperature of the gauze covered thermometer stops falling. A number is derived by subtracting the temperature reading of the gauze-covered thermometer from the reading on the other one. That number, along with the actual temperature (from the dry bulb thermometer) is used with the help of a table to determine the level of humidity in the atmosphere.

Dry Bulb        Dry Bulb minus Wet Bulb (degrees Celsius)

°C	1	2	3	4	5	6	7	8	9	10
10	88	77	66	55	44	34	24	15	6
11	89	78	67	56	46	36	27	18	9
12	89	78	68	58	48	39	29	21	12
13	89	79	69	59	50	41	32	22	15	7
14	90	79	70	60	51	42	34	25	18	10
15	90	81	71	61	53	44	36	27	20	13
16	90	81	71	63	54	46	38	30	23	15
17	90	81	72	64	55	47	40	32	25	18
18	91	82	73	65	57	49	41	34	27	20
19	91	82	74	65	58	50	43	36	29	22
20	91	83	74	67	59	53	46	39	32	26
21	91	83	75	67	60	53	46	39	32	26
22	91	83	76	68	61	54	47	40	34	28
23	92	84	76	69	62	55	48	42	36	30
24	92	84	77	69	62	56	49	43	37	31
25	92	84	77