Patricia A. McCarrin
Pre-assessment Report
EDUC 536-361
Due – December 3, 2005
Part 1:
Background Information on the Content Topic
A. Background on Hurricanes:
Summer
storms can be exhilarating to watch move over the ocean and onto the land. The rough waves are welcomed by surfers and swimmers who like to be tossed about in the
water, but they can turn deadly, an unwelcome force that can have, devastating
effects. The winds can become so strong that they rip buildings apart
and push huge amounts of water over the land. The
Hurricanes
are large spiraling systems with sustained wind speeds of at least 74 mph that
have the potential to increase to 200 mph.
Because of the way the earth rotates, these storms spin counterclockwise
in the Northern Hemisphere and clockwise in the Southern Hemisphere. They are a worldwide occurrence but only
around the
The Atlantic hurricane season
starts when summer arrives. It officially begins on June 1 and continues
through October, but most of the storms take place between August 15 and
October 15, during which the most
powerful hurricanes usually occur. These storms originate primarily, in the
region off of
Hurricanes develop in stages moving from a tropical wave to a depression, a storm and finally a hurricane. Tropical waves are the most common. About 100 are formed each season. Winds do not circulate and wind speeds are only about 25 mph. Next are the “tropical disturbances”, defined as “an organized group of thunderstorms often found over a tropical ocean that generates a slight cyclonic flow of less than 37 kilometers per hour” (physical geography.net), occur and persist for a period of at least 24 hours. These tropical disturbances develop in areas where surface air “piles up.” (physical geography.net) The wind flows into the region and has nowhere to go but up because it cannot penetrate the land or water. This pile up is known as convergence. Rising and sinking of air in the atmosphere results. As it rises it becomes saturated and the base of a cloud forms. The clouds grow into gigantic bulbous formations because the moist air in the tropics is not in a stable condition: the air is less dense than the unsaturated air around it which causes it to accelerate upward and form these huge clouds. For a tropical disturbance to move toward tropical storm stage, the disturbance must be in a trough, which is an extended area of low pressure (physical geography.net). These troughs have a weak, partial cyclonic rotation and fall into three categories: monsoon, frontal, and surface. Monsoon troughs are most associated with hurricane formation.
These
monsoon troughs are found in areas where the temperature of the air increases
as it moves away from the equator. The Intertropical Convergence Zone is the
name given to this region. There is
almost always a series of thunderstorms in this zone. This spot along the equator receives the
strongest rays of the sun. The intense
heat causes a large amount of evaporation which is changed to “sensible heat,”
defined by the Arctic Climatology and Meteorology
Primer as “the heat absorbed or transmitted by a substance during a change
of temperature which is not accompanied by a change of state.” Along this
trough the North and South trade winds also converge. The zone “moves
seasonally with the tilt of the Earth’s axis.”
(http://www.physicalgeography.net/fundamentals/7u.html)
One other phenomenon that could be responsible for beginning a hurricane is something called a tropical wave. This wave breaks off from a monsoon and travels a continual distance westward then strengthens. These waves are where most Atlantic hurricanes originate if the other conditions are in place.
Warm seas are the second criteria needed for a hurricane to develop. Heat moves from the ocean to the air. This generates and maintains the thunderstorms in a tropical disturbance. The sea surface, depth to about 200 meters, should be a temperature of 80 degrees F or more. The depth is important because the hurricanes generate huge waves. If only a few meters were heated the waves would churn and bring cooler water to the surface cutting off the supply of warm water needed to stimulate the storm.
The third condition necessary to fuel a hurricane is a weak vertical wind shear which is a sudden change in the speed of the wind and the direction it is traveling. Wind usually moves horizontally but these conditions can cause a sudden downdraft. For a hurricane to originate the winds need to be about the same speed and blowing from the same direction at all height levels in the atmosphere. (Http://weather.jsums.edu/hurricane.htm)
When the above conditions are present, the rising air stimulates the low lying air causing it to flow toward the center. This inflow slowly increases the circulation of the disturbance. When the circle is enclosed, it graduates to being called a tropical depression and the circular flow will have speeds between 23 and 39 mph. The weak wind shear is important at this point because it maintains the low-level inflow and allows for vertical orientation of the thunderstorms. The storms stay together as long as the winds remain constant and it does not move over colder water or land.
When all
the conditions stay in place the cyclonic winds will continue to slowly
increase; the storm is fueled. The air
beneath is driven up faster sucking in additional air from below. The new air spirals in and also rises sucking
in more air and the storm gains more and more power. This is because as the
wind increases, increased heat and moisture is transferred from the ocean to
the air. The column of air warms and
this lowers surface pressure. Air will
try to redistribute its weight by moving from higher pressure to lower. This in turn causes the winds to
increase. This enhances convergence
which is the force that drives the hurricane.
As a result of the Coriolis
Effect, trade winds push the
entire system west across the planet, the spiral tightens and the storm becomes
even stronger. A column of clear air
develops. This is the eye of the storm,
an area ranging in size from 10 to 50 miles.
It is the calm interior of the storm, believed to be so because the
winds are circling at such a fast rate that centrifugal force pushes the winds
away from the center. Here updrafts
surrounding the eye are balanced by air going back down inside it. This is
called the eye wall. It contains the
strongest and fiercest of the winds. Somewhere out in the
Hurricanes are considered to be the deadliest and most destructive of the planets severe weather. High winds rip off roofs, damage crops and people have been killed when hit with the flying debris. Rain can be torrential causing mud slides and flooded fields. The deadliest of the conditions however is the storm surge or tide, the water pushed toward the land from the sea by the force of the wind. If the shore line is shallow and the tide is high the storm surge can reach 30 feet. This water rushes onto the land with destructive power flooding everything in its path. Beaches are eroded, highways and bridges washed away, homes and businesses are destroyed. Lives are lost.
Even today with sophisticated meteorological equipment the path of a hurricane is difficult to predict. Years ago storms of this type caught people by surprise; without warning people would not know to evacuate and some of the deadliest of the hurricanes occurred prior to the development of current day equipment. Because of the havoc they wreck, scientists have worked diligently to develop even more sophisticated methods. In order to predict the path of such storms a lot of information is needed. This information is gathered from many source: planes, ships and special flights designed to look for signs of potential hurricane formation. Today satellites from space give meteorologists the best information. Geo Stationary Operational Environmental or Go Satellites are one of the newest methods of viewing the paths of hurricanes. They allow meteorologists to view images of clouds spiraling away from the equator, providing a constant series of pictures to be studied. The biggest challenge is to predict the curve of the storm. Currently the National Weather Service can provide warnings 12 to 24 hours in advance of the approaching hurricane. Even with this more advanced equipment, it is not always enough to predict the exact path of a hurricane. Some educated guess work is still necessary. Meteorologists would like to be able to dissipate a hurricane before it develops and several groups are investigating methods to do this. However, the potential consequence of tampering needs to be examined. Hurricanes provide rain to drought areas. They flush bays of pollutants and help restore there ecosystem. They also get rid of the weakest of plants and animals leaving the strong to survive and reproduce. They are responsible for moving the air around the planet.
B. Standards
National Science Education Standards
Science As Inquiry – Content Standard A – Students can begin to recognize the relationship between explanation and evidence. They can understand that background knowledge and theories guide the design of investigations, the types of observations made, and the interpretations of data. In turn, the experiments and investigations students conduct become experiences that shape and modify their background knowledge.
Standard A - Specific to topic of hurricanes:
Students will make observations and consider information that can best answer data.
Students will think critically about evidence. They will review data and form a logical argument about the cause and effect relationship.
Physical Science – Content Standard B – All students should develop an understanding of the properties and changes of properties in matter, forces and motions and transfer of energy.
Standard B – Specific
to topic of hurricanes:
Students will need to have an understanding of:
The characteristic properties of water.
Energy as a property of many substances and the means in which it is transferred.
How heat moves in predictable ways, flowing from warmer objects to cooler ones, until both reach the same temperature.
Earth and Space Science – Content Standard D – All students should develop an understanding of the structure of the earth system, earth’s history and the earth in the solar system.
Standard D –
Specific to topic of hurricanes:
Students will need to have an understanding of the water cycle, the atmosphere, and global patterns of atmospheric movement and how they influence local weather. They will also need to explore oceans and their effect on climate.
Science in Personal and Social Perspectives – Content Standard F – All students should develop an understanding of personal health, populations, resources and environments, natural hazards, risks and benefits and science and technology in society.
Standard F – Specific
to topic of hurricanes:
Natural hazards can present personal and societal challenges because misidentifying the change or incorrectly estimating the rate and scale of change may result in either too little attention and significant human costs or too much cost for unneeded preventive measures.
Risks analysis considers the type of hazard and estimates the number of people that might be exposed and the number likely to suffer consequences. The results are used to determine the options for reduction or eliminating risks.
Students should understand the risks associated with natural hazards, in this case specific hazards related to hurricanes.
Individuals can use a systematic approach to thinking critically about risks and benefits.
Important personal and social decisions are made based on perceptions of benefits and risks.
Technology influences society through its product and processes. Technology used by meteorologists greatly influence the understanding of weather phenomenon.
C. Relevant Research
Research shows that the following misconceptions
could be a hindrance to students studying about hurricane formation since heat
transfer is a major source of hurricane development. In Joseph Stephans’
book “Targeting Students’ Science Misconceptions” he explains that children
have difficulty understanding heat and how it transfers. He believes these misconceptions could result
from everyday language that is used when describing heat and temperature. He states that heat and temperature ideas are
counterintuitive and therefore it is easy for students to develop
misconceptions on these phenomena. He
further states that confusion could arise because of the implication that is
given that states, things possess heat or do not possess heat. All things possess heat and have the
potential to transfer this heat to another source of lower temperature.
According to the Benchmarks on Energy
Transformation, grades 6 through 8, there may also be confusion in children’s
minds about energy and its sources. Energy does not get used up but can change
form. Where would the energy to create a
hurricane come from and how could this energy be sustained? Students may not understand that surfaces
heat at different rates and hold heat at varying rates which would hinder their
comprehension of how these mediums conduct heat to the air above it, (transfer
energy). Not understanding this concept
would, according to Stephan, make it difficult for them to understand how heat
transfers and the process of convection.
In addition research has been identified that targets
misconceptions regarding weather and is particularly relevant to children’s misconceptions
of air and its properties. Many children
believe that humid air is denser than dry air, (Aron,
Francek, Nelson & Bissard,
1994) and that the atmosphere is made up solely of air. Students do not think about water vapor as
being a component of air but rather think that water vapor transfers into air
itself. (Smith & Ford, 1996)
Not understanding how
water vapor is related to air or how humid air would more likely cause rainfall
because of its height in the atmosphere would be other hindrances in
understanding this topic.
Part II:
Analysis of pre-assessment results
A. Brief description of the class
Currently I
am working with two groups of students.
They are divided into two single sex classes, 19 boys and 21 girls. Thirty
five students are African Americans , two are Hispanic
and three are of other origin. Drew
is the neighborhood school for most of the students but several students from other neighborhoods come
because they had older siblings here or their family moved and they didn’t want to change schools. The students are from a low socioeconomic
background: all are eligible for
free lunch. The classes contain students
from shelters and group homes.
Some of
the students have very little supervision or support from their homes. Others
are laden with responsibility such as watching their younger siblings until
their parents get home. A majority are
from single parent homes.
The range
of abilities is very varied in the
boy’s class. I have 4 that are classified
as mentally gifted, four that go
to learning support and 11 in between
though these are generally closer to the lower half.
The girls class is less polar, most fall in the average range.
I see the students the equivalent of
three periods a week for science, one ninety minute period, when I do labs, and
Many of the children like science, particularly hands on labs, but it is difficult to get them to make the connections between the labs and the concepts that are meant to be grasped through the labs. The students in general have a difficult time writing coherent summaries of what took place even when they are given time to discuss and allowed to work in groups. If I model how I would go about it, they want to copy exactly what I am saying.
The assessment took a class period. I introduced the topic by talking about Hurricane Katrina and asked how many might be interested, by a show of hands, in finding out more about hurricanes. There was no one that did not express interest.
I gave the students the table of hurricane occurrences. We looked at the dates together and discussed the times that the hurricanes took place. I then had them respond to the first of the pre-assessment questions.
Next I
projected images on screen from the Hurricane Archive, (http://weather.chron.com/hurricane/at195403.asp)
These images allowed the students to see origins and paths of many of the hurricanes
that develop in the
After this I gave the students pictures of Hurricane Katrina, Floyd and Andrew. These showed the tracking of the storm over several days. The students viewed the storms as they moved over the ocean and onto the land.
They discussed the progress of the storm in groups and then answered the second and third questions on the pre-assessment.
B. Rational for the questions that I used
The
next unit of study is Weather and Climate.
Hurricanes are a small portion of the unit but one of high interest that
could drive student’s interest to learn about weather and its conditions.
The
topic is authentic because as stated in Chapter 2 of “Teaching Science in the
Elementary and Middle School Classrooms,” it is a topic that is relevant to
students, connects to their lives outside of school, and has a plethora of
science concepts that would need to be investigated in order for them to be
able to answer the driving questions, “Would a hurricane like Katrina ever hit
the Philadelphia area?
The questions are designed to generate further interest in the topic and could be, as noted in chapter 3, page 101 of “Teaching Science in the Elementary and Middle School Classrooms,” a method to encourage students to ask questions, “in this case additional questions, “that might be turned into mini investigations that would support the driving question.
Since
research states according to the Benchmarks for Science Literacy, p. 6, that children should be involved in thinking scientifically
and encouraged to ask questions about nature, I thought the pre-assessment questions fit into this
specific standard.
In addition the National Science
Education standards require that “transfer of energy” be included in the
6through 8 grade curriculums. Research states as earlier cited that this is an
area of difficulty with this age student.
The questions were designed to be open ended enough for me to make some speculations about what the students need to know before they study hurricanes, allowing me to outline some prerequisites such as being able to make predictions, analyze data and interpret graphs. The second question requires students to think about the cause and effects of hurricane movement. This type of question according to our text, chapter 4, page 127 is where the students in the upper elementary and middle grades should be performing.
Students have come to class with preconceived
ideas and a certain amount of background information. These questions will give me insights into
what they have already learned about the topic and any misconceptions that they
have developed which would hinder their learning on this subject. By pre-assessing their knowledge I can
analyze where they are and design my lessons accordingly.
C. Analysis of
children’s responses to questions.
Question 1
In analyzing the results of the pre-assessment questions, I looked for the following in question 1:
Did students relate the time of year to warm temperature of
the ocean?
Did students relate the time of year to warm air
temperatures?
Did students write about winds and their involvement with hurricane formations?
|
28 students surveyed |
Warm Temp. of Ocean |
Warm Air Temp. |
Winds |
No mention of necessary conditions |
|
|
0 |
2 |
9 |
19 |
The students looked at the chart and related the occurrences of the hurricanes with the change in seasons. In their mind the weather gets colder as the months move closer to October. They made no connection to the fact that the water had a long period of time to warm and that summer is not considered officially over until September 21. The land temperatures change slightly, particularly in the evening because the land heats and cools at a faster rate than water but water takes a lot more time to heat and cools more slowly. For water to heat to a temperature of 80 degrees to a depth of 200 meters it needs the long summer to make the change.
Conclusion -Students have relatively little understanding of the conditions necessary for a hurricane to form.
Question 2
Students need to again know the conditions that are necessary for a hurricane to form but also need to know what it needs to sustain itself. Warm ocean, warm air temperatures, low wind shear
Did students note that the storm increased in strength as it
moved over the water?
Did students note that the storm rapidly decreased as it
moved over land?
|
28 students surveyed |
Increased in strength over water decreased over land |
Only mentioned increase or decrease without connecting the two |
Could write why |
No intelligible response |
|
|
10 |
2 |
1 partial |
16 |
Students made note of the hurricane getting larger and
smaller but only one child made mention of the fact that the hurricane gathered
some of its strength from the warm water.
Surprisingly the children did not all relate the connection between the
dissipation of the storm and the land.
They did seem to be able to interpret that the hurricane grew larger and
smaller but not with the direction of movement.
There were two students that mentioned the eye but they did not
correlate this with the strength of the hurricane.
D. Discussion of Findings
Students did not
understand how long it takes a mass of water of this magnitude to heat, the
fact that it would require most of the summer, or how the heating of this mass
was involved in the transference of heat to the air above it. In fact they
disregarded it completely in question one and believed that the onset of the
fall, colder weather, was a reason for hurricane formation. This suggestion
that Stephans’ findings are relevant in this
situation. The students do not have an
understanding of the properties of heat and how radiation, conduction and
convection play a major part in hurricane development. They attributed the stronger hurricanes being
caused mostly by cooler air and disregarded the warm ocean temperature heated
by the radiation of the sun for long periods, the transference of this heat to
the atmosphere through conduction and the convection process that would circulate
the warmed, not cool fall, air.
The students that responded did see
that the storm decreased in intensity as it moved over the land but could not
articulate the reason for this dissipation.
This shows that they were able to interpret the visual representation
but they are not able to articulate the reason.
This suggests that they do not understand where the energy from the
hurricane is derived and how it transfers or does not transfer energy, another
difficult concept as mentioned in the above Benchmarks for children of this
age.
E. Implications of Findings
Students had a high interest in this
activity. They immensely enjoyed the
on-line tracking of the hurricanes and were fascinated by the pictures of the hurricanes
mass and development. They wanted to
know how fast the hurricanes turned, why they moved in certain directions, and
how they moved. This enthusiasm leads me
to believe that it is a topic that could provide an authentic investigation.
Students were able to look at a table and draw conclusions but the
conclusions they drew were inaccurate revealing a poor understanding of what
was transpiring. More information is
needed to better understand their misconceptions. In the future I would use the research sited
by Stephans and the Benchmarks on heat and energy
concepts to further pre-assess there understandings. Getting a clearer understanding of there
misconceptions in these areas would better help me understand what would be
needed for them to be able to comprehend hurricane phenomena.
Based on the findings I have several areas that I would introduce as mini
lessons as the students continued research on hurricanes. Each topic would include an informal
pre-assessment to help me determine the amount of dept needed for the lessons.
Bibliography