Work Samples




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SHARED ASSIGNMENTSBelow are samples of assignments submitted for this course with names removed so as not to violate anyone's privacy.

They are examples of the quality of work I expect.

The assignments you see here are not necessarily the best work for that assignment
but examples chosen at random from among all of the assignments I consider well done.

I change assignments from time to time so make certain you are looking at an example based on your current assignment rather than a previous assignment.

In assignments that ask for specific right or wrong answers, I have substituted Xs for the answers so as not to tempt you!

If you don't see an example of a particular assignment, it's because I haven't yet found one to post.


Activity #1

Weather- such a simple word implying so much meaning for the way Earth is Earth. We take away one cog that makes our weather system work and we have a different planet. I discovered this running the program "Make Earth's Weather." I experimented with many configurations of the program and found only one set of parameters that made a planet that it considered similar to earth. Let us look at each choice that was available within the program and find out why, in my opinion, it ended up to be a viable choice for a habitable planet.

Within the program, the first choice you have to make is the angle of the sun. After reading all three choices, I went with the angle of the tropics because it provides seasons, though it did appear that the sun over the equator might also work. However, seasons seem to help the life cycle of the planet. The cycle of seasons give time for land to nourish itself and for plants to grow based on the distribution of light, cool, and heat. Seasons distribute and circulate the energy around the planet allowing for plant nourishment and growth. Seasons make life easier on us, though, according to some theories, life could exist without them. The second choice was the rotation of the planet. The only option that made sense for human life was the rotation of 24 hours. The other two would lead to conditions making life nearly impossible. Either the temperature would be unbearable or the wind would be too deadly. The third choice was the surface of our planet. Choices were a surface of water and land, or just land. The obvious choice was land and water. Water mass plays a necessary part of the weather system that cannot be replaced if there is to be human life on the planet. The water mass provides a place for temperature to be stored and carry heat around the globe. Lastly, we have planet size. The choice that provided earth like conditions was medium size. If it was larger or smaller, the magnetic pull would be significantly different and would also affect the air we breathe. The size would also affect our atmosphere changing how much radiation gets through.

My planet has a sun angle over the tropics, a rotation of once per 24 hours, surface and water, and lastly medium size. This gave me the earth like results I was looking for. These combinations of factors allow my planet to have the weather and climate required for life. They also allow the combination of temperature, moisture control, pressure and wind that form weather patterns necessary for life. This combination of factors supports the tangibles needed to replicate an earth like atmosphere. Thus, oceans create rains, winds and the earth's own gravitational pull and generate our weather patterns. Pressure differences work in conjunction with the earth's rotation to create the Coriolis Effect, changing the streams of air called the Jet Stream. This Coriolis Effect is an important reason why weather is constantly changing at every latitude throughout the world. It functions with the convection cells, help work with jet streams in pushing the weather conditions over the globe.

In conclusion, this exercise has shown me the basics of weather knowledge and how it plays a vital part of survival on a planet such as Earth. It is fascinating how all the factors making weather work is all a chain and interlocked with each other. It makes me understand the uniqueness of earth and its inter-working to be a habitable planet. It makes me appreciate the weatherman more when they are predicting the weather. My impression of the weather system is of awe and wonderment and has given me the appetite to learn more about it.

Activity #1

1.   The new planet created here will start off by having a sun angle directly related to the equator. The first change made here was from having the sun angle on the tropics to the equator.  Having this causes the equator to always be the warmest spot on the globe, and causes for an absence in seasons because the further away from the equator someone goes, the colder they get. This will always be true because there are no seasons. If there were seasons, then the temperature would change according to the way the sun is positioned. This is a far change from the sun being positioned at the Tropics like in the planet Earth. Originally, the planet had a rotation of once per 24 hours, but then was changed to never. After seeing that never rotating causes one side in total darkness, switching to once every 10 hours was another change made. The surface of the new planet will have land, and ocean. This is no change from Earth, as the Earth has land and oceans. As far as the surface is concerned, this new planet will look similar to Earth. The new planet size will be changed from medium, which is Earth, so a smaller planet similar in size to Mars. This will cause a lower gravity, and less extreme changes in temperature than Earth.

2.   The Earth has the sun angle of 27.5 degrees, but the reason for changing it to 0 degrees and making it over the equator is so that the new planet will always have a warm spot, and a cold spot. It also eliminates the seasons, so the temperature at the poles is constantly cold, while the temperature at the equator is constantly hot. Also, the days become shorter at the poles, and thus is way less sunlight at the poles, which explains why it’s cold year-around on each pole. For the rotation of the new planet, once every 10 hours is a far cry from once every 24 hours like Earth. The reason for this change is to create a planet that is spinning over twice as fast as Earth. That would be a unique situation because it would feel like moving at high speeds all the time. It also generates high prevailing winds and tides, which is the other reason for making this change. The reason for having land and water on the new planet is with the equator always being hot and the tides being strong, oceans would be needed. With oceans and strong tides, there could be quite a storm that could develop on the new planet. Lastly, changing from medium-sized Earth to a smaller planet was chosen because it gives a lower gravity, and really thin atmosphere. The thin atmosphere will cause the heat to spread quickly and have more constant temperatures than temperatures that fluctuate.

3.   The final results for the new planet have one similarity to Earth, but the rest are differences. The final result that is the like Earth is that the new planet has land and ocean. This was the way to go because it would be extremely hard to sustain life without water, although the differences make it hard to sustain life on the new planet also. The sun angle for the new planet is over the equator, while the rotation of the planet is once every 10 hours. Finally, the size of the planet is a smaller planet similar to the size of Mars.

4.   The sun angle feature of creating the planet is directly related to what is being studied in class. When I mentioned about the Tropics and the equator, each of them deals with the longitude and latitude of the Earth. The longitude and latitude of a location determine where exactly the equator, tropics, and poles are, thus I used the information gathered from this concept to determine where I wanted my sun angle to be. Also, the sun angle over the equator deals with the concept of seasons as well. Since each spot of the Earth is consistent with temperature, there are no seasons. The main two concepts that help determine my answers came from the longitude and latitude of the sun angle, and the seasons. Learning about each of these helped to gauge on which sun angle was picked for the new planet, and over the equator seemed like a good choice. After learning from the margin notes that the seasons cause fluctuation and change in temperature, going with no seasons seemed easier because that would not have to be worried about.

Activity #1

1) Every change that I tried to make seemed to be unsuitable for living; therefore, I ended up creating a planet along the lines of Earth. I gave it a sun angle of 27.5 degrees, a rotation of once every 24 hours, a surface of land and ocean and a medium size.

2) Once I realized that none of my other combinations was going to work, I worked on mimicking Earth's details. I started with the rotation and surface, since those were the easier of the two. After that, I chose the size of the planet, after remembering that Earth's size is quite comparable to Venus. Finally, it just came down to trial and error with the sun angle. I eventually was able to come up with the perfect mixture.

3) The final results gave me Earth. The description said that "this world has a thick, moderately warm, moist atmosphere, four seasons and a global ocean that generates clouds and rain, moderating overall temperatures. Rotation establishes the Coriolis Effect and ever-changing cyclonic weather. The poles are cool, tropics warm, mid-latitudes temperate."

4) For starters, the entire assignment was much like the scientific method with all of the making assumptions, testing them out, re-assuming, etc. Besides that, the entire rest of the unit seems to be about Earth and how it its axis tilt, size, shape, etc. work together to create a (mostly) perfectly balanced planet that is suitable for living. If just one tiny thing is changed, it could throw off the entire balance of the planet, much like making a different choice on the "Make Earth's Weather" activity changed the planet we were working with.

Activity #1

1. I made what may seem to be very minor changes I set the planet up with these options:

1. Sun Angle: 27.5 deg. (sun over tropics)

2. Rotation: Once every 24 hrs. (normal)

3. Surface: Land and Ocean (normal)

4. Size: Large (Neptune Size)

2. The reason I made these specific changes are because:

            1. I thought it would be interesting to see a bigger earth.

2. When I put the sun’s angle to 27.5 it seemed the earth was warmer though upon looking back it leaves one end colder (which partly included the U.S. I don’t like this particularly but it was fun to experiment)

    *tried the 0 deg. first but didn’t like the outcome.

3. It has a dense, very warm, moist atmosphere. The weather is ever-changing with sometimes violent cyclonic weather. This earth has four seasons. The ocean moderates temperature while a strong gravity creates atmospheric stiffness this encourages many circulation patterns and wind bands. The size of the planet creates colder poles, hotter tropics, and more storms. The rotation angle causes the weather to lag behind the equinoxes therefore spring occurs in May instead of March 21.

4. The thing that stands out the most in this activity was the atmospheres changes. When changing each of these options you see the effect on the atmosphere for example: I used 0 deg. sun angle first and noticed that instead of what my final earth’s atmosphere has (a dense, very warm, moist atmosphere) it had a thick, moderately warm, moist atmosphere. The individual part of the atmosphere most affected was the lithosphere because of the changes in the weather and climate.

            1. Changing the size of the earth would relate to geodesy.

            2. We see the change in seasons or the lack there of.

3. We also see that changing the rotation of the earth would directly relate to our concept of time, how long a day is, etc.

Activity #2

Global warming is the raising of the Earth's temperature due to the excessive emission of Carbon Dioxide and other greenhouse gases into the Earth's atmosphere. The emission of greenhouse gases has been on the rise since the advent of the Industrial Revolution and has continued to increase ever since. This is not only due to the burning of fossil fuels but also the burning of vast forest areas. The Wide Angle document "Burning Season" shows Indonesia moving up third in rank in terms of carbon emissions in the world just by the burning of their forests. In "Burning Season," Dorjee Sun, an Australian entrepreneur, is trying to save the Indonesian forest by selling its carbon credits to the more industrialized countries. This document shows that it is too late to choose between either government regulation or market forces alone to regulate the emission of greenhouse gases. Both the government and the free market working together will be more effective in saving the planet from global warming.

The Kyoto Protocol, with its cap and credit system, has made it possible for countries to recognize carbon as a tangible material because there is now a cost attached to it. Countries that have reached their cap on emissions can purchase credits from countries that did not use all of their allotted credits in the given time. As a result, carbon trading is now a viable, profit-making business. Whether companies such as Meryll Lynch are trading carbon credits for profit or because they want to help save the environment, the end result is the same – less carbon emissions. “Burning Season” shows a farmer trying to make a living the only way he knows how - clearing the forest to grow oil palms. Now, however, the free market system will offer this farmer and others like him alternative solutions of making a living, which does not include burning their forests.

The 2007 Bali convention agreed that the Earth’s forests would now be a legal source of carbon credit. This means that countries with forests will now be paid by “western polluters” to keep their forests intact, to act as a “septic tank” by absorbing the carbon emissions from the polluting countries. This is extremely beneficial to poorer, third world countries that are fortunate to have this natural resource, such as Indonesia. The Governor of Aceh, Indonesia wants to ensure that the money gained from the selling of the carbon credits trickles down to the local farmers. He wants to implement “Aceh’s Green Vision,” where the deforested land around the now protected forest can be used by the farmers to grow cash crops such as fruit trees, cacao and oil palms. The locals can also be employed as care-takers of the forests and its wild-life.

Saving the Earth from carbon emissions has to be a global effort. There needs to be a solution that everyone can be a part of. A solution that ensures that in the process of saving the Earth we do not forget that the small farmers and business owners of poorer countries also need to make a living. This is why market forces together with government regulation can help make a viable difference. The government regulation is necessary so as to implement a legal cap on greenhouse gas emissions, and also to ensure that the money gained from carbon trading is put to fair use. The free market system with its market forces will ensure that our forests are saved because it now has a monetary value and the emission of carbon remains at a reduced state. An additional bonus of market forces is that poorer countries can gain additional income just by keeping their forests alive.

Activity #3

The virtual river assignment was an excellent example of how confined flows function and how hydrologists measure and determine the average velocity and discharge from particular flows. The activity itself focused on the data collection and calculations for determining the averages. The resulting data, modeled the concepts important to understanding the movement of surface water and the methods of determining their average velocities and discharges. It is important to note that the averages will not only vary from flow to flow, but it will vary over the course of time.

In every instance the quality and composition of the soil determines the holding capacity of that soil, which affects the potential runoff in to streams and rivers. Once the holding capacity has been met; runoff is more likely to travel into confined flows. The increase of runoff will increase the velocity of the river or stream and the stream discharge. In addition to runoff precipitation directly over the confined flow plays a role in the increase of both velocity and discharge as well. There is a notable discrepancy between times of peak precipitation and peak stream discharge. This is due to the time is take the water to permeate through the soil, to allow for the soil's holding capacity to be met and continue as runoff to the streams and rivers.

An extreme scenario would be that of a flash flood, where large amounts of precipitation occur over a short period of time, in the same general area. Usually brought on by a stationary front. This causes the holding capacity of the soil to be exceeded quickly and results in rapid runoff and an immediate increase in the velocity of the stream or river. In some cases permeability of ground water from the base of a river or stream also plays a part in the velocity and discharge averages of streams and rivers. It also is what keeps them flowing all year.

Activity #3

Data Set

Mount St. Helens

Crater Lake

Lassen Peak

Long Valley

Valles Caldera

La Garita




1882 km

2011 km

1890 km

1770 km

1126 km

1046 km

1432 km

885 km


Crater / Caldera Size: 2 x 3.5 km

Largest Eruptive Volume: 1 km3

Crater / Caldera Size: 8 x 10 km

Largest Eruptive Volume: 35 km3

Crater / Caldera Size: 213 x 122 m

Largest Eruptive Volume: 50 km3

Crater / Caldera Size: 17 x 32 km

Largest Eruptive Volume: 600 km3

Crater / Caldera Size: 20 x 22 km

Largest Eruptive Volume: 600 km3

Crater / Caldera Size: 35 x 75 km

Largest Eruptive Volume: 5000 km3

Crater / Caldera Size: ~80 km

Largest Eruptive Volume: >1000 km3

Crater / Caldera Size: 45 x 85 km

Largest Eruptive Volume: >2000 km3

Ash Composition


Not very similar to compounds at Ashfall


Only Phosphorous Pentaoxide was similar to Ashfall


Not very similar to compounds at Ashfall


Not very similar to compounds at Ashfall


Not very similar to compounds at Ashfall


Only Calcium Oxide was similar to Ashfall


7 of 9 chemical compounds had attributes very similar to Ashfall


4 of 9 had attributes very similar to Ashfall

After evaluating the eight volcanoes I came to a conclusion that the Volcano Bruneau-Jarbridge in Idaho was to blame for the ash deposits in Ashfall Nebraska. I came to this conclusion first by eliminating some of the volcanoes by the distance the volcano is from Ashfall. Since a super volcano produces extremely large eruptions the can reach up to 1,500 kilometers since a number of the volcanoes didn’t produce 1,000 cubic kilometers therefore couldn’t reach past 1500 kilometers I eliminated them as possibilities, that left me with only three volcanoes: Yellowstone, the closest possibility; La Garita, with the largest eruption volume; and Bruneau-Jarbridge, in between the two. Then I evaluated the ash composition of the three remaining volcanoes to the ash composition at Ashfall and was able to eliminate La Garita immediately, and then yellow stone, leaving Bruneau-Jarbridge with almost identical ash composition of that of Ashfall. While I felt the ash composite was most important in determining the volcano responsible I went back and checked that the distance of the volcano was applicable to the amount of the eruption volume. Bruneau-Jarbridge produced more than 1000 km3 therefore it would have been able to reach Ashfall, which is 1432 km away.

1. A caldera-forming eruption is most likely the source of the ash at Ashfall, NE because calderas are the most dominate form of felsic volcanoes. Felsic volcanoes are highly explosive with extensive ash fall like that at Ashfall.

2. Compared to the other volcanoes La Garita had the highest silicon dioxide levels and was the most explosive volcano.

3. I think that Bruneau-Jarbidge was the most likely source that caused the ashfall and killed the animals in Nebraska, because the ash composition is almost identical to the ash composition in Nebraska.

4. As I analyzed the data my opinion changed about three times. From the beginning I saw that Yellowstone was closest to Ashfall, but then discovered that La Garita was not much further away than Yellowstone and had a much higher eruption volume. My opinion then changed once again when I saw the ash composition of La Garita and Yellowstone was not that similar to that of Ashfall, and that Bruneau-Jarbidge had almost an identical composition as Ashfall.

5. I believe the ash Composition data was the most relevant in finding which volcano was possibly responsible.

6. While all data did not point to the same answer, I believe all information given was needed to come to a conclusion.

Activity #4



Critical Thinking Essay

On August 28, 2005, a powerful hurricane made landfall on the southern coast of the United States, leaving a trail of mortality and devastation in her wake. Commanding winds and heavy rains tore violently at the infrastructure of the Gulf Coast, leaving millions without power for days and thousands of others completely homeless or displaced. Louisiana and Mississippi were most affected by the behemoth “category five” storm – known infamously as Hurricane Katrina – with over one-thousand fatalities reported in the city of New Orleans alone. While Hurricane Katrina made her mark as one of the worst natural disasters in U.S. history, it should be known that despite its heavy socioeconomic impact, this mighty hurricane was only a single unit among a multitude of powerful, intense storms that have been documented over the past sixty years.

Meteorologists, in their attempt to trace the cause of the alarming increase of intense hurricanes and tropical storms, have made innovative strides in the study of hurricane dynamics and have gathered a remarkable amount of data regarding the atmospheric and environmental influences on the formation of these powerful forces of nature. While reviewing the results of their studies, these scientists identified an astonishing trend: the average oceanic temperature has increased half a degree on the Celsius scale within the past forty years. In that same time period, the number of intense hurricanes has simultaneously multiplied twofold. Given the mounting evidence of augmented anthropogenic global warming, meteorologists fear that the sharp increase in oceanic temperatures – and the subsequent rise in the number of intense hurricanes – may be the result of anthropogenic global warming, or global warming brought forth by human activity. Numerous statistical and methodological errors have been made in the investigation processes in relation to this trend, however, and more evidence must be gathered before global warming can be positively correlated with the increased number of intense hurricanes that have formed within the past forty years.

Scientists who argue the intensifying effect of anthropogenic global warming on hurricanes cite a distinct correlation between increasing oceanic temperatures and an increased number of intense hurricanes as the basis of their argument. It has been well-documented that a trenchant positive correlation exists between ocean temperature and hurricane intensity; however, it should be emphasized before any inferences can be made regarding this concept that the apparent evidence of correlation does not necessarily indicate a definite causational relationship between oceanic temperature and hurricane intensity. Meteorological phenomena such as hurricanes are caused and closely affected by a variety of aligning factors, such as wind speeds and the presence of vertical wind shear. While it would be perfectly acceptable to draw correlational parallels between ocean temperature and hurricane intensity, to assert that a single factor such as oceanic temperature is responsible for an increase in hurricane intensity and the number of intense hurricanes without sufficient data to sustain this assertion would be fallacious. Additional evidence is required to confirm, or nullify, the theory of the causational relationship between oceanic temperature and hurricane intensity.

Reiterating an important fact, it is well-known within the meteorological community that warmer ocean waters tend to generate stronger tropical storms and hurricanes than cooler waters, and that the ocean has warmed significantly within the past few decades. What is not addressed (or at least, not widely addressed) is the exact cause of the increase in ocean temperature itself. It would be erroneous to assume that anthropogenic global warming is unilaterally responsible for the increase in ocean water temperature, as water temperatures tend to vary based on a variety of different factors. Though it is highly probable that global warming may have played a role in the elevation of ocean temperatures, all parameters that could lead to such an elevation must first be examined before one can determine that global warming is a direct cause of the ocean temperature elevation and the subsequent increase in the number of powerful hurricanes. Furthermore, the anthropogenic nature of global warming itself warrants scrutiny. Human activity is undoubtedly a contributing factor in the proliferation of the global warming effect, yet how it contributes to changing weather patterns, especially those which beget hurricanes, remains to be seen.

Since the early 1950s, meteorologists have gained more capacity to study hurricane dynamics than could have been imagined in the prior years due to advancements in the use of measurement tools, improved research methods, and the increase in the ability for scientists to collaborate and share data. Nevertheless, while such remarkable innovation is credited as being the driving force for the current research on global warming, it has also created an orifice in the accuracy of research statistics. Skeptics have called the accuracy of data collected using earlier research methods into question, and rightly so; numerous discrepancies in obtained data were identified as changes in research practices were implemented. For instance, scientists have drastically changed the way cyclonic wind speeds are monitored within the past few decades. Since the accurate measurement of wind speeds is a vital step in determining hurricane intensity, researchers have experienced a great deal of difficulty identifying accurate trends due to an extensive divergence in the data collected before and after the changes in cyclonic wind speed monitoring were employed. In addition to evolving research methods, meteorologists have and continue to use tools in their research that may contain flaws in their functionality. General circulation models (GCMs), for example, are exceptional predictors of global weather patterns, yet they cannot provide a realistic model of the onset and intensity of relatively smaller weather systems such as hurricanes because of their oversized scale. Meteorologists have created a smaller-scale model (the regional climate model, or RCM) that can provide a more realistic representation of hurricane activity, but it does not take certain variables such as wind shear variability or the El Niño-Southern Oscillation phenomenon into consideration. In order to form acceptable conclusions regarding global warming and it’s affects on hurricane intensity, the aforementioned discrepancies and errors in research methods should first be corrected, and the methods themselves must be optimized to allow for the collection of more precise data.

A sharp rise in the amount of powerful hurricanes in recent years has created quite a tumultuous uproar within the scientific community over the past decade. Many scientists fear that global warming – influenced by human production of greenhouse gases – may have played a role in the skyrocketing number of intense hurricanes by causing ocean waters to warm considerably. However, to accept such an assertion as a scientific fact at this point in time would be irrational. There is much to be accomplished before global warming can be attributed to or ruled out as the cause (or among the causes) of the increased amount of powerful hurricanes that form. Research methods must be improved so that any data collected on the matter is as accurate as possible, and weather models used in meteorological research should be improved for better accuracy. Additionally, scientists must confirm or refute the theory that the increased amounts of powerful hurricanes are in fact caused by warming ocean waters, and not other meteorological factors. If warmer waters are indeed related to the global warming phenomenon, the anthropogenic nature of global warming must be assessed so that the correlation between human activity and the increase in strong hurricanes can be established. Currently, there is insufficient evidence that suggests global warming is somehow tied to an increase in the amount of powerful hurricanes, yet this fact may change as more data is collected and more ideas are explored.

Critical Thinking Essay

The data from the reading selection does provide enough evidence to suggest a connection between climate change and the intensity of hurricanes. However, when looking for additional data, I found some articles that state the contrary. These articles suggest that the increased destruction from the storms is due to either other factors in the creation of the storms or variables that are totally independent of the storm. I would have to do significant additional research, just as I would suggest for anyone studying this topic to do before deciding whether global warming is tied to variations in the intensity of tropical storms. Some of these articles site reasons for why the sea surface temperatures are increasing. I certainly don’t believe there is enough credible evidence to make the case that climate change is Anthropogenic.

Many of the articles and papers including a Geophysical Liquid Dynamics Laboratory article, Global Warming and Hurricanes, agree that greenhouse warming has not contributed to an increase of the quantity of tropical storms. This site like many others in the assigned reading do claim that there has been an increase in the intensity of the storms. This statement that the intensity of the tropical storms has increased due to elevated sea surface temperatures seemed to appear nearly verbatim in many of the assigned reading articles. Elevated hurricane intensity does not seem to be the only factor to consider in the increased amount of damage done by storms reaching land in the recent past

A study published in Natural Hazards Review and highlighted on the National Oceanic and Atmospheric Administration Web site found that increased property damage and losses from hurricanes are not due to increased intensity, but instead the increased coastal population. This is not only due to an increase in the number of people living near the coast, but also an increase in the value of the property built there. (Pielke et al. 2008) While the amount of people and money near the coastline has increased in the past few years thus raising the amount of property that has been destroyed in storms, there is still some debate as to if and why the storms have increased in intensity

An additional article published in Nature stated that while there is debate about whether global warming has contributed to increased intensity of tropical storms, another factor should be considered. “The response of tropical cyclone activity to global warming is widely debated… It is often assumed that warmer sea surface temperatures provide a more favorable environment for the development and intensification of tropical cyclones, but cyclone genesis and intensity are also affected by the vertical thermodynamic properties of the atmosphere.” (Vechi and Soden 2007). This statement appears to be in line with the discussion of hot towers as seen in the video from NASA. The Vechi paper goes on to note that sea surface temperatures variations are not sufficient to even use as an indicator of potential storm intensity. The article states that long-term intensity changes are more closely related to regional weather structure. In addition, this paper mentions something that I didn’t see in many other articles. This is that the recently recorded temperatures are very close to those readings from the 1930’s to the 1950’s. This suggests the cycles in ocean temperatures

It is very interesting that in an article by Thomas R. Knutson, his conclusions stated at the beginning of the article conflict. He says it is too early to determine that human activity has had any impact on Atlantic hurricane activity. In the very next statement, he says human impact could increase the severity of these storms. (Knutson 2010). A lot of the material in this article is based on SST that has been collected over the past couple of centuries. This data has been called into question by some other researchers for the potential to be wrong. The inaccuracies are thought to come from sources such as inaccurate testing tools, less frequent testing and the use of modeling and extrapolation. The temperature readings and other data gathered prior to 1950’s are especially under scrutiny. This is partially because of the lack of plane-based measuring equipment as well as less aggressive testing techniques. By validating previous temperature recordings and validating the accuracy of calculated historical temperatures, scientists could determine causes of increased SSTs

There have been many references to cyclical fluctuations in both atmospheric and oceanic temperatures. These swings could also have some responsibility for the increased intensity of tropical storms and hurricanes. This finding published by the World Climate Report shows that the temperature swings in the Atlantic are closely related to the temperature swings in the other oceans. This is a finding that hasn’t seemed to get as much attention in some of the other articles. “There is a strong correlation between the SST changes in the tropical Atlantic Ocean relative to tropical SSTs in other ocean basins and Atlantic tropical cyclone activity.” (World Climate Report 2008) The article also states that the Atlantic warms more quickly than some of the other oceans. “In recent decades, the tropical Atlantic Ocean has warmed faster than other tropical oceans and thus, Atlantic tropical hurricane activity has picked up, both in frequency and intensity.” (World Climate Report 2008) There is additional data showing that when greenhouse gases are included in the model, the changes in intensity are still caused by the natural cyclical temperature swings. “As climate models run with increasing atmospheric concentrations of greenhouse gases do not project that the tropical Atlantic will warm faster than other tropical oceans, future tropical cyclone in the Atlantic will be driven by natural fluctuations in the patterns of tropical SST increases rather than simply an overall SST increase.” (World Climate Report 2008) This is another example of why scientists should take a very critical look at the calculations and models for figuring historical temperatures through the Middle Ages. Ensuring these readings are as accurate as possible would help to determine if the increased hurricane intensity is cyclical and if it was pushed by increased temperatures or some other factor. Accurate readings would also help to determine if elevated SST is due to human influence or if it also follows a cycle

I’m not completely discounting that the variations in SST could affect the intensity or even frequency of tropical storms. My point is just that like the argument that humans may or may not be responsible for climate change, there needs to be significantly more research and a common-sense approach used before attempting to implement any proposed solutions for a hypothesis that has not been proven to be caused by climate change

Works Cited

Pielke, Roger A. Jr., Gratz, Joel, Landsea, Douglas Collins, Saunders, Mark A., Musulin, Rade Feb. 2008 “Normalized Hurricane Damage in the United States: 1900-2005.” Natural Hazards Review 29-42. http://sciencepolicy.colorado.edu/admin/publication_files/resource-2476-2008.02.pdf. (April 8, 2010)

Vechi, Gabriel A., Soden, Brian J. 2007 “Effect of remote sea surface temperature change on tropical cyclone potential intensity.” Nature December 13 http://www.nature.com/nature/journal/v450/n7172/full/nature06423.html. (April 8, 2010)

Knutson, Thomas R., 26 March 2008 “Has Global Warming Affected Atlantic Hurricane Activity?” Geophysical Fluid Dynamics Laboratory http://www.gfdl.noaa.gov/global-warming-and-hurricanes (April 8, 2010)

World Climate Report November 3, 2008 “Natural or Anthropogenic Effects on Atlantic Hurricanes, Past, Present, Future?http://www.worldclimatereport.com/index.php/2008/11/03/natural-or-anthropogenic-effects-on-atlantic-hurricanes-past-present-future/. (April 8, 2010).[link not active]


Field Manual – see available downloads on the Unit 8 page.

Chapter 9 Summary

I. Introduction

1. Hydrosphere includes:

· Surface water of oceans, lakes, rivers, and swamps.

· Underground water.

· Frozen water which includes ice, snow, and high-cloud crystals.

· Water vapor in atmosphere.

· Moisture temporarily stored in plants.

II. The Hydrologic Cycle

1. 90% of water is stored in oceans, lakes, streams, frozen as glacial ice, or kept in rocks below the surface of the Earth.

2. Hydrologic cycle – series of storage areas interconnected by various transfer processes, in which there is a ceaseless interchange of moisture in terms of its geographical location and its physical state.

A. Surface – to – Air Water Movement

1. Most of the moisture from the Earth’s surface that enters the atmosphere comes from evaporation.

2. Approximately 86% of the evaporated moisture originates from the oceans.

B. Air – to – Surface Water Movement

1. Water vapor in the atmosphere will either condense into liquid water or sublimate to ice in order to form cloud particles.

C. Movement on and Beneath Earth’s Surface

1. Runoff – flow of water from land to oceans by overland flow, stream flow, and groundwater flow.

2. Any of the water that gathers on the surface of the Earth either evaporates, sinks into the ground, ends up in the ocean through runoff, is stored temporarily as moisture in the soil if it is infiltrated water, or percolates and becomes part of the underground water supply.

D. Residence Times

1. There is variation in the amount of time it takes water to pass through the hydrologic cycle.

2. Water moving through the cycle is almost always continuously moving.

III. The Oceans

1. Oceans provide a harsh environment for the majority of air-breathing organisms and our knowledge of them has been fairly restricted until recently.

A. How Many Oceans?

1. Four Oceans:

· Pacific

· Atlantic

· Indian

· Arctic

B. Characteristics of Ocean Waters

1. Chemical composition

· Salinity – measure of the concentration of dissolved salts.

2. Temperature

· Higher than 80° F in locations near the equator and as low as 28° F in the Arctic.

3. Density

· Changes depending on temperature, level of salinity, and depth.

IV. Movement of Ocean Waters

1. Tides, currents, and waves.

A. Tides

1. Tides – rise and fall of the coastal water levels caused by the alternate increasing and decreasing gravitational pool of the Moon and Sun on varying parts of the Earth’s surface.

2. Flood tide – movement of ocean water toward the coast in a tidal cycle.

3. Ebb tide – periodic fall of sea level during a tidal cycle.

4. Tidal range – vertical differences in elevation between high and low tide.

5. Spring tides – time of maximum tide that occurs as a result of the alignment of Sun, Moon, and Earth.

6. Neap tide – lower-than-normal tidal variations that occur twice a month as the result of the alignment of the Sun and Moon at a right angle to one another.

7. Tidal range depends on the coastline’s shape and the pattern of the sea bottom.

8. Tidal bore – wall of seawater several centimeters to several meters in height that rushes up a river as the result of enormous tidal inflow.

B. Currents

1. Surface currents are caused by the flow of the wind.

2. All other currents depend:

· Size and shape of ocean.

· Pattern and depth of ocean bottom.

· Coriolis Effect.

3. Thermohaline circulation – slow circulation of deep ocean water because of differences in water density that arise from differences in salinity and temperature.

4. Global conveyor – belt circulation – slowly moving circulation of deep ocean water that forms a continuous loop from the North Atlantic to the Antarctic, into the Indian and Pacific Oceans, and back into the North Atlantic.

C. Waves

1. Majority of the ocean surface is constantly agitated through wave crests and troughs.

2. Waves found in the open sea are mainly just shapes.

V. Permanent Ice – The Cryosphere

1. Ice on Land:

· Alpine glaciers

· Ice sheets

· Ice caps

2. Oceanic Ice

· Ice pack – extensive and cohesive mass of floating ice.

· Ice shelf – massive portion of a continental ice sheet that projects out over the sea.

· Ice floe – large, flattish mass of ice that breaks off from larger ice bodies and floats independently.

· Iceberg – chunk of floating ice that breaks off from an ice shelf or glacier.

A. Permafrost

1. Permafrost – permanent ground ice or permanently frozen subsoil.

VI. Surface Waters

A. Lakes

1. Lake – body of water surrounded by land.

2. Majority of the world’s lakes are freshwater, but some of the biggest contain salt water.

3. The human population has altered lakes by diverting water for things such as agriculture.

4. Reservoirs – artificial lakes.  

B. Swamps and Marshes

1. Swamp – flattish surface area that is submerged in water at least part of the time but is shallow enough to permit the growth of water tolerant plants – predominantly trees.

2. Marsh – flattish surface area that is submerged in water at least part of the time but is shallow enough to permit the growth of water tolerant plants, primarily grasses and sedges.

C. Rivers and Streams

1. Streams:

· Drains water from the land’s surface.

· Moves water, sediment, and dissolved chemicals to the sea.

2. Drainage basin – all the land area drained by a river and its tributaries.

VII. Underground Water

1. More than 50% of the underground water in the world is located within approximately half a mile of the Earth’s surface.

2. Porosity – amount of pore space between the soil and particles and between the peds, which is a measure of the capacity of the soil to hold water and air.

3. Permeability – soil or rock characteristic in which there are interconnected pore spaces through which water can move.

4. Interstices-the pore spaces; labyrinth of interconnecting passageways among the soil particles that make up nearly half the volume of an average soil. 

5. Aquifers – permeable subsurface rock layer that can store, transmit, and supply water.

6. Aquicludes – impermeable rock layer that is so dense as to exclude water.

A. Zone of Aeration

1. Zone of aeration – topmost hydrologic zone within the ground, which contains a fluctuating amount of moisture in the pore spaces of the soil.

B. Zone of Saturation

1. Zone of saturation – second hydrologic zone below the surface of the ground, whose uppermost boundary is the water table.

2. Groundwater – water found underground in the zone of saturation.

3. Water table – top of the saturated zone within the ground.

4. Cone of depression – phenomenon whereby the water table has sunk into the approximate shape of an inverted cone in the immediate vicinity of a well as the result of the removal of a considerable amount of water.

C. Zone of Confined Water

1. Zone of confined water – third hydrologic zone below the surface of the ground, which contains one or more permeable rock layers that into which water can infiltrate and is separated from the zone of saturation by impermeable layers.

2. Piezometric surface – elevation to which water will rise under natural confining pressure in a well.

3. Artesian well – free flow that results when a well is drilled from the surface down into the aquifer and the confining pressure is sufficient to force the water to the surface without artificial pumping.

4. Subartesian well – free flow of that results when a well is drilled from the surface down into a confined aquifer and which requires artificial pumping to raise the water to the surface because confining pressure forces the water only partway up the well shaft.

D. Waterless Zone

1. Waterless zone – fifth and lowermost hydrologic zone that generally begins several kilometers or miles beneath the land surface and is characterized by the lack of water in pore spaces due to the great pressure and density of the rock.

E. Groundwater Mining

1. High rate of groundwater use is compared to mining because a finite resource is being removed without any hope of replenishment.



Copyright © 1996 Amy S Glenn
Last updated:   04/01/2020   0130

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