Posts under ‘Science’

Welcome to the Around the Americas Science Program blog. For background on the Program, visit the overview page, or download The Science Aboard, a four-page summary in PDF format. Lastly, a complete list of Science posts is available here.

Sound Around the Americas: The Hydrophone Project

Jan 14th, 2010

by ATA.

By Dr. Peter Dahl
Principal Engineer, Applied Physics Laboratory and
Associate Professor, Mechanical Engineering
University of Washington, Seattle WA

A hydrophone, or underwater microphone was installed on Ocean Watch in order to provide the Around the Americas team with a simple, uncomplicated way to record and study the underwater sound during the voyage. Sound provides one of the most important ways to study the underwater environment.

Before we discuss the hydrophone measurements, we will provide some background information about the basic properties of sound and why it is used to study the oceans. Sound is generally used to study the underwater environment because water is far more absorptive of light than air, whereas sound travels well in water. Sound is a mechanical wave that is produced when a sound source sets the surrounding molecules (of gas, solids, or liquids) into motion. In fluids, the speed at which sound travels depends on the compressibility and density of the medium through which it is traveling. In sea water, however, this translates to sound speed being dependent on temperature, salinity and depth. Sound can be used ‘passively’, where someone only listens to the sounds around them, or ‘actively’, where someone generates a sound and then listens to echoes produced when the sound is scattered or reflected by underwater objects or fish. In most settings, the underwater environment will always have some kind of ambient or background noise – whether due to man-made sources such as boat engines, or due to natural sources such as marine mammals or snapping shrimp.

One of the science goals for Around the Americas was to obtain measurements of ambient noise in ports-of-call, and other protected and sheltered waters as the team circumnavigates the continents of North and South America. It is of interest to understand the variation of underwater sound levels with latitude as it is influenced by snapping shrimp populations that are more prevalent within tropical latitudes. Snapping shrimp are crustaceans and one of their most interesting characteristics is the sound a single shrimp can produce when its claw is snapped shut at very high speed. The ambient noise environment can often dominated by the chorus of sounds from many shrimp.

As Ocean Watch entered lower latitudes, beginning with a stop in the port of Charleston S.C., interesting sound measurements, likely associated with snapping shrimp either from the genus Synalpheus or Alpheus, began to emerge. In particular, the trend that emerged was a change in the ambient noise level with latitude, which is illustrated in the following two figures. Figure 1 shows the locations of the various ports-of-call and Figure 2 shows the sound pressure spectrum (showing the different frequency contributions to the overall sound) for three low-latitude ports compared with measurements made in the port of Barrow, Alaska. The horizontal-axis corresponds to sound frequency, plotted logarithmically; the vertical-axis shows the sound level observed for a given frequency, expressed in decibels (dB), which is also a logarithmic scaling. Sound frequencies within the nominal range 2 – 20 kHz (red, dashed line) are characteristic of the sound spectrum produced by snapping shrimp. The spectral estimates were made by Robert Burns, an undergraduate research fellow at the University of Washington Applied Physics Laboratory. Go to the following link (MP3 file) to listen to a sampling of the sounds from snapping shrimp recorded on October 16th 2009 by Dr. Michael Reynolds from the Ocean Watch while it was in Charleston Heritage Marina , South Carolina. This location is close to the 33rd parallel-or the approximate northern boundary of snapping shrimp.

As the Around the Americas cruise team enters more tropical waters we anticipate the ambient sound levels in the 2-20 kHz range to further increase, and then eventually to decrease once again as they enter high latitudes in the southern hemisphere.

For more information about snapping shrimp and underwater acoustics, please go to the ‘Discovery of Sound in the Sea’ project web site (http://www.dosits.org) developed by the University of Rhode Island’s (URI) Office of Marine Programs (OMP) in partnership with Marine Acoustics, Inc. of Newport, RI.

Fig. 1 Ports within which the ATA team has measured underwater ambient noise.

Fig. 2. Pressure spectrum of ambient noise from the last three lower-latitude ports, compared with one from Barrow, Alaska. (The peak in the Barrow spectrum is possibly machinery noise.) Sound frequencies within the nominal range 2 – 20 kHz (red, dashed line) are characteristic of the sound spectrum produced by snapping shrimp.

Crew Log 160 – S. Atlantic Currents: Battling the N. Brazil Current

Dec 29th, 2009

by Dr. Michael Reynolds.

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December 29, 2009 – Mar del Plata, Uruguay

By Dr. Michael Reynolds

Michael Reynolds, Ph.D. Background
With apologies, this document is about three weeks late. Ocean Watch is now in the much colder waters of Mar de Plata where the temperature is in the mid 20’s,–that’s in degrees Celsius. In Fahrenheit it is in the upper 70’s ºF. See my note on units below. It is partly cloudy, and the Nuevo Año celebrations are cranking up. Life is good-today.

However, we were not such happy sailors on December 4. We were into probably the most depressing part of the voyage. Those of you who followed our daily situation, especially the courageous daily blogs that Herb and David delivered with a stamina worthy of the best war correspondents, are aware of the situation. Hindsight is the best viewpoint and misery is so quickly forgotten. But this report was written in the heart of the drive to Rio. To fully appreciate it, read this in a sauna.

December 4, 2009. We are currently at 2º-35′S,40º-50′W plowing along the north coast of Brazil. We are trying to progress in a southeast direction along the coast, then round the corner and head south down to Rio. In San Juan we began to hear about the difficulties of this portion of our voyage. The current and winds would likely be against us and the going would be very slow and very uncomfortable. Well, there was nothing to do but press on and so we departed Puerto Rico on November 8. After a short visit to the island nation of St. Lucia, we began the push south and, just as expected, the going was tough. The slow going required a fuel stop and we selected Cayenne, French Guyana as the best option. A visit to this French territory with its good food and pleasant people was fun but put us further behind schedule. On November 22, at 6:30 in the morning we weighed anchor and sailed out for seven very tough days.

In this report I want to give you a picture of our world that week. Herb and Mark have made numerous references to this difficult sailing situation. They talked of the heat, rough seas, and head winds, but my report will talk about the oceanography and might give some insight into the sort of oceanography going on in this little corner of the Atlantic ocean. So, take a breath and dig in. Stay with me for a two-minute course in tropical oceanography and to paraphrase Betty Davis, wear your seat belts; it’s going to be a bumpy ride.

Fig 1. The wind regions if there were no continents. If the Earth were not rotating the heating from the sun would force a single convection cell from the equator to both poles. The rotation forces the flow into smaller cells; the trade wind easterlies, the westerlies, and the polar easterlies. The continents add to the complexity.

Trade Winds Drive the Equatorial Currents (See Fig. 1.)
We begin with the trade winds. In a world without continents, the global wind systems, shown in Fig. 1, is one of the most efficient means of transporting heat from < ;script type=”text/javascript”> // –> the equator where the sun-light is direct to the much colder north and south poles. The rotation of the Earth guides the air flow into cells; the trade winds, the westerlies, and the polar easterlies. The continents complicate things considerably but the basic patterns still exist.

The trade winds are steady winds, about 15-20 knots, that are directed to the equator. In the northern hemisphere they are directed to the south and in the southern hemisphere they are directed to the north. Due to the rotation of the Earth, they tilt to the west in both hemispheres. The resulting wind fields (by convention winds are described by the direction they come from) are the NE trades above the equator and the SE trades below the equator, or simply the Easterlies. In Oceanographic terms “forcing” is the push the winds give to the surface currents. The direction of the forcing is in the direction toward which the wind blows. The trade winds produce a constant westward forcing across all the tropical ocean. Bear in mind, this is all a very general “average” picture of a turbulent fluid field.

The doldrums are a region near the equator where the north and south trade winds converge. North and south of the equator the trade winds flow toward each other and along the way they take up water by evaporation, becoming thick with humidity. When they meet they rise up into the atmosphere and lose their water by precipitation. Therefore the doldrums are the narrow band of towering clouds, squalls, and high humidity. (Actually the trade winds do not meet exactly at the equator, but usually within a few degrees north.) The name doldrums, meaning low spirits, a feeling of boredom or depression, is well suited. The doldrums lie between two and seven degrees north, approximately. Clouds in this region reflect the high humidity and the sudden release of energy that accompanies the rainfall. An example of towering cumulus clouds and an anvil cloud where the tower reaches the stable top of the atmospheric troposphere is given in Fig. 2 (Please refer to main photo above. This photograph was taken at sunset as Ocean Watch makes its way south to the doldrums. The convergence creates towering cumulus clouds that precipitate and grow to the top of the atmosphere.)

The westward wind forcing creates ocean currents called the equatorial currents that flow along the equator to the

Fig 3. A sketch of the major ocean currents in the central Atlantic Ocean. A red dot shows the location of interest. The system of equatorial currents is well defined in the east and the North Brazil Current, fed from the different south equatorial currents, dominates the west. This current is the primary way surface water is exchanged between the north and south Atlantic Oceans.

west. The two wind-driven equatorial currents push quite a bit of water toward Brazil where it piles up and looks for somewhere to go. One result of the western currents is a thin counter current, the equatorial counter current, that snakes between the north and south equatorial currents.

The equatorial currents meet Brazil (See Fig. 3.)
Most importantly, the North Brazil Current is formed and pushes huge amounts of water northward into the north Atlantic where it joins the Gulf Stream. The North Brazil Current is much smaller than the Gulf Stream, about 1/4 the volume, but it is important because almost all of the exchange of surface water from the southern to the northern hemisphere takes place here. Without the North Brazil current the North Atlantic Ocean would be an almost closed body of water.

Gyres in the current (See Fig. 4.)
Like eddies in a stream, the North Brazil Current, Gulf Stream, and all the other boundary currents often form swirls called rings. Fig. 4 shows the currents we faced leaving Cayenne on November 22. It was not a good picture. A huge ring (also called a gyre) was sitting right in front of us. Currents in the gyre were as high as 4 knots to the north. We considered two choices. Either we could leave Cayenne and turn south to hug the coast and push against the constant 1-2 knot currents or we could try sailing well offshore to the other side of the ring and then catch a ride south. This was a good plan but it required conditions to cooperate.

Fig 4. Currents during our Cayenne-Sao Luis passage. A large gyre dominates the area. The current direction in the gyre is clockwise. The plan for as Ocean Watch was to go well offshore and into the low velocity core then turn south and catch the south currents. East winds and slower than expected going force a compromise to the plan then a dive into Sao Luis. The current map is a product of the University of Miami called HYCOM. It is available for any location through http://buoyweather.com.

No help from the winds
Such was not the case. Fig. 4 shows our location each day from November 22 to November 29. Winds seldom allowed good sailing. Instead of the nice NE trade winds we expected and hoped for, we faced winds that were almost directly from east or even southeast. Do you remember I said above that the doldrums, the place where the north and south trades converge is just above the equator? It so happens this line was almost exactly at 3 degrees N. As a result our tack out was depressing (the doldrums), gray, thick with squalls and dotted with severe wind shifts. Head winds prevented any pure sailing except for short durations. Fuel was low. We were in the middle of nowhere. It was time to head to a port and so on November 29 we entered the harbor of Itaqui.

Around the horn with a new plan
We left Itaqui, the port for Sao Luis, Brazil on December 1. This time we had a different plan. We would sail as close to the coast as possible. There was no secret for escaping this situation altogether — we had to choose the better of bad options. We ended up heading in a SE direction into SE winds and NE currents. Southbound boaters to Rio, beware the North Brazil Current.

Michael Reynolds, Ph.D.
michael@rmrco.com
Remember: all views, ideas, and comments here are ad hoc, off the cuff, minimally researched, and subject to revision at any moment.
Reference for Figures 1 & 3.
Regional Oceanography: An Introduction. M.Tomczak and S.Godfrey
(2001) http://www.es.flinders.edu.au/~mattom/regoc/pdfversion.html

Notes on Units:
Knot: A knot is the universal maritime measure of distance. It is based on the spherical Earth where a nautical mile is one minute of latitude, that is 1/60 of a degree. A knot is one nautical mile per hour. Therefore, is we are headed due south averaging 5 kts for a full day we will cross two degrees of latitude. Roughly a knot is half a meter per second and a little bit more than one mile per hour.
1 kt = 0.5144 m/s = 1.15 mph.
Centigrade: In America we cling to the old Fahrenheit degree while the rest of the world and the world of science has been using the Celsius (or Centigrade) degree for the past decades. Americans will adapt, they must, so why not now? A quick rule for converting from ºC to ºF: double the temperature, subtract 10%, and add 32.

For me I remember that 0C = 32F, 10C = 50F, and 28C ~= 82F. Then you get an idea of the rest.

This crew log submitted by Iridium OpenPort and Stratos

Cloud Observations Aboard Ocean Watch for the NASA S’COOL Program

Dec 27th, 2009

by Dr. Michael Reynolds.

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December 27, 2009
By Dr. Michael Reynolds

Michael Reynolds, Ph.D. The report below was co-written by Dr. Lin Chambers, Director of the NASA CERES S’COOL Project. For more information on the S’COOL project see the links listed below.

Clouds. Every person living on Earth has seen them. We all know that they bring us rain, snow, shadows, interesting shapes. However, clouds play a crucial role in the Earth climate system. Since we have had the vantage point of looking at Earth from space, we know that about half of the planet is always cloud-covered – in beautiful, shifting patterns. Besides bringing weather, these clouds play an important role in the Earth’s energy budget. They affect the amount of sunlight that reaches the Earth’s surface, and the amount of heat that escapes back to space.

Albedo. Sunlight is reflected by white (or light colored) materials and is absorbed by dark colored materials. Clouds reflect sunlight back to space and in so doing they help cool our climate. Without clouds, the temperature of the Earth would increase substantially as more of the Sun’s energy would reach the surface. The fraction of sunlight reflected back to space is called albedo. Both clouds and snow contribute to albedo but clouds are the main contributor. Today about 28% of the total energy from the sun is reflected to space.

Fig. 1. A photograph taken at sunset as Ocean Watch makes its way south to the doldrums (described in the science report on the Brazil Current). The convergence creates towering Cumulus clouds that precipitate and grow to the top of the atmosphere. This photo shows the complexity of cloud observations. We see a towering Cumulonimbus anvil cloud that grows from near the surface up to several thousand meters. Winds at altitude sweep the top of the cloud away as it grows to make the anvil shape. Along the horizon are low Cumulus clouds. Above the Cumulus is a mixture of mid-level, Alto Stratus, and high, Cirrus clouds. Each cloud type has a different effect on the global energy budget so a measure of cloud fraction for each type is a critical.

High clouds and low clouds. As scientists have delved into the details of studying clouds, they have learned that the picture is not simple. Depending on what type, or level of clouds is present, clouds can actually have opposite effects on energy flows. High, thin clouds (i.e., the wispy-looking cirrus) actually have a warming effect on the Earth: they let in sunlight but do not allow heat to escape. Low, thick clouds (i.e., fluffy-looking cumulus or featureless stratus) have a cooling effect: they reflect the Sun’s light back to space, but also allow heat to escape from their relatively warm cloud tops. Currently scientists are delving even deeper into the details of clouds, and how they may respond to changes in the environment. This requires lots of information, both from space and from the ground.

Cloud observations from space. Our understanding of the physics of clouds has been highlighted as a key uncertainty in the reports of the Intergovernmental Panel on Climate Change (IPCC). Understanding this part of the Earth system is one of NASA’s highest priority scientific research areas. NASA studies clouds from space with a special instrument called the Clouds and the Earth’s Radiant Energy System (CERES). There are CERES instruments currently on three Earth observing spacecraft: TRMM (launched in 1997), Terra (launched in December 1999), and Aqua (launched in 2002). The instruments on Terra and Aqua are still operating at this time, with Terra holding a 10th anniversary celebration in December. Both Terra and Aqua overfly essentially the entire Earth every day. Using measurements obtained by the CERES instrument, scientists seek to gain a better understanding of the role of clouds and the energy cycle in global climate change. CERES provides high accuracy measurements of reflected sunlight and heat energy leaving the Earth. The team then uses other instruments on Terra and Aqua to identify the cloud conditions associated with those measurements. Ground observations of clouds are an important component of the CERES program. Observations made from Earth provide “ground truth” validation of the satellite measurements. Quality assurance grows with more ground truth observations.

Fig. 2. An example of a cloud image from above the Arctic Circle. The far north is dominated by vast shields of low Cumulus Stratus, and also challenges the satellite with bright snow and ice often covering the surface. In this situation the ground observer cannot see higher cloud layers, but can trivially distinguish clouds from snow or sea ice. Observations from space and the ground provide complementary information.

S’COOL. The Students’ Cloud Observations On-Line (S’COOL) project began in 1997 to collect surface observer reports of cloud conditions from widely distributed K-12 schools for comparison to the space-based measurements. S’COOL is administered from the Langley Research Center in Hampton, Virginia. S’COOL observations are used as a source of “ground truth” to assist in the validation of the cloud identification from space.

Ocean Watch Observations. The voyage of Ocean Watch is adding substantially to the S’COOL database by contributing observations from interesting places around the American continents where students don’t normally go. Ocean Watch is reporting observations through the S’COOL Rover component, launched for the 12th anniversary of the project in early 2009. In contrast to the main S’COOL Project, which collects cloud observation reports from fixed sites (i.e., schools), the Rover aspect allows people or groups anywhere in the world to obtain satellite overpass schedules and submit reports. With a moving platform such as Ocean Watch – and one with limited connectivity to the internet at that! — predicting the satellite overpass times is somewhat of a challenge, but the crew has worked out a system and done quite well. A large number of their observation reports have been matched to satellite data, which requires observing within +/- 15 minutes of the time that the satellite passes over the sailboat position. This tight time-matching is required because clouds can change substantially in short time periods, and we want to be sure that we are comparing ‘apples to apples’ and getting as much information as possible to compare to the satellite.

Fig 3. Screenshot from S’COOL Rover website showing the comparison between the observation report from the Ocean Watch crew and the corresponding satellite retrieval of cloud information for that time and location. This comparison corresponds to the satellite image in Fig. 2. This and other Ocean Watch reports are accessible from the S’COOL Rover database (see link below).

Results from the S’COOL program. Since the S’COOL Project began, here are some of the things we’ve learned:
1) The satellite is often not able to detect small amounts of thin cirrus cloud, which are easily seen from the ground. This is because the satellite has limited spatial resolution from its location ~700 km above the surface, and also because of the challenge of detecting thin clouds against the variable background of the Earth surface. An observer on the surface, in contrast, is looking for clouds against a fairly uniform background: the blue sky.
2) Sometimes clouds at one level are obscured by clouds at other layers. For instance, ground observers provide important complementary information about the lower layers of clouds, while the satellite instruments can view the uppermost layer. Newer, remote sensing instruments, such as CALIPSO or CloudSat, now provide vertical profiles of cloud layers all the way to the surface. These instruments are considered ‘active’ sensors, as they create their own source of illumination using lasers or radar, but they can only profile a thin strip of clouds immediately under the satellite track.
3) There are indications that the satellite algorithms are still sometimes confused by the presence of snow or ice on the surface, despite the best efforts of the CERES team to correctly separate clouds from snow. Since both are cold, bright surfaces, this is a big challenge for satellite observations. It is no challenge at all to a student standing on snowy ground to see even small wisps of cloud in the sky. We continue to seek data from snowy or icy parts of the world to better understand when and where this is or is not a problem.
4) Taken overall, the cloud coverage reported by students and other observers is in good agreement with the cloud coverage measured from the satellite instruments.

Conclusion. Studies continue on these and other aspects of comparisons between surface and satellite-based observations. We plan a focused study on the complete set of Ocean Watch reports to determine whether we can learn any new things from a number of previously unobserved areas along the route of the Around the Americas voyage. The entire database of reports since January 1997 is also accessible on the S’COOL website for anyone who might be interested. These observations are one important piece in understanding the puzzle that clouds represent.

Links:
S’COOL home page http://scool.larc.nasa.gov
S’COOL Rover Database http://scool.larc.nasa.gov/en_view_rover.html
CERES home page http://science.larc.nasa.gov/ceres
Aqua Satellite http://terra.nasa.gov
Terra Satellite http://aqua.nasa.gov
CALIPSO http://www-calipso.larc.nasa.gov/
CloudSat http://cloudsat.atmos.colostate.edu/

Crew Log 134 – Science Q & A

Nov 28th, 2009

by Dr. Michael Reynolds.

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Novemver 28th, 2009 – From the On-Board Scientist
by Dr. R. Michael Reynolds

Michael Reynolds, Ph.D.

SCIENCE QUESTIONS AND ANSWERS
We receive questions from time to time. These usually come to us through the science@AroundTheAmericas.org email and sometimes through my personal email, michael@rmrco.com. This report will answer a few of these questions. I’ll answer another batch in the near future. If you like these questions then send me others so we can begin a dialog.

WASHINGTON VIRTUAL ACADEMY
A group of about 30 K-8 students in a virtual school called Washington Virtual Academy (http://www.k12.com/wava /) are

Main Photo (see above) This photo is taken in the evening facing southeast toward a bank of towering Cumulus clouds. Ocean Watch is headed in a SE direction and you can see from the wave rows the wind is coming from the east just to port (left) of our direction. This has been our problem. We cannot sail in these winds without tacking to the right into land or to the left, which would put us well out of our way, even heading north. The pink cloud color comes from the setting sun behind the camera.

following the expedition. If you have internet access, check out the very impressive website their teacher created here: http://www.wavaoceanwatchers.com/index.html
The teachers, Nancy Mayer and Joy Roth, found out about the project during a local Seattle newscast (King 5) and they are very excited about the project.

Here are some questions from the students:

Q. Did you see signs of Cruise ships dumping sewage in the Gulf of Alaska?

No. We see many cruise ships, especially here in the Caribbean. They are especially apparent in the night with all their lights, but every cruise line I know of practices a policy of “nothing overboard.” And they mean it. No garbage goes over, no raw sewage, nothing.

Q. Do you guys alternate watch on the boat at night, or do you put the boat into auto drive, so you can sleep? How cold is it out there at sea?

Some of our readers might not know what “watches” are. A rule is that someone must be awake in the cockpit at all times. We are divided into two groups. Each watch group will be on duty to operate the boat while the others are free to sleep, eat, or just relax. Here are the hours of the day corresponding to shifts for being on watch. There are three day watch shifts (assuming a 24-hour clock): 06-10, 10-14, and 14-18; there are four night watch shifts: 18-21, 21-00, 00-03, 03-06. Each group takes turns being on watch. As I write this note it is 2:50 in the morning and my watch is almost over. I will only have three hours to sleep and then will have to be back up at 6 am. Believe me, when it is three AM and you have had only two hours of sleep and there is absolutely nothing to see, and the radar screen is black and the ocean is bare, staying awake is very difficult.

Now you asked about being cold. Well, I received this question when we were in the Arctic. It has taken time to answer these questions, and cold is not the issue for us now. Right now we are about three days from crossing the equator and the big issue is the heat. It is really HOT! Ocean Watch does not have air conditioning and we have to keep all the hatches closed because of the splash from waves. Therefore the temperature inside is usually 92^o F. There is no circulation except for some tiny fans. Sleeping is impossible.

Q. What will the ripple effect be when the coral reefs are affected by the warmer temperatures?

In the past several years we have lost nearly 30% of the planet’s reefs for a variety of reasons, but increasing ocean temperatures is one of the main reasons. There is hope that by introducing temperature-tolerant species of zooxanthellae (recall zooxanthellae are plants that live mutually under the skin of the coral polyps and are crucial for coral health) we can help corals to survive on a warmer planet. If this approach does not succeed, there will be tremendous changes in the types and distributions of coral reefs. Unless steps are taken to slow down the warming of the global oceans, we can expect to see terrible losses.

Q. We would like to know what is the first thing you will do when you get to port?

It is funny, but the first thing we do is look for good Internet connections…such is life in the twenty-first century. If there is a good WiFi link at the dock then within minutes we will all be sitting up on the deck with our laptops open. Otherwise you will find us headed into town looking for Starbucks or any internet cafe. Bars, hotels, or museums come second.

UNIVERSITY OF PUERTO RICO, ENGLISH

Dr. Eva de Lourdes Edwards is a professor of English at the University of Puerto Rico and a member of Sailors for the Sea. She teaches ocean awareness to her classes. While we were in San Juan she came with students for a tour of Ocean Watch. Interacting with such a smart and enthusiastic group of young people makes me hopeful for the future! After their visit they prepared a list of questions for us; you can read about Eva and her work at http://sailantilia.blogspot.com.

Q: In addition to watching the ocean, what other things do you do during the voyage that you may not put in the website? (Jenni)

Ocean Watch is a small boat (I have to remember to call this a boat, not a ship) and our crew is only six people. Therefore there are chores we all must share. I cook dinner or clean the dishes sometimes. I help keep the boat clean. I stand watch like everyone else.

Q: What do you think about the contamination problems in the ocean around the Americas? (Yineza and Kenny)

I am very concerned about how humans have treated the oceans as a dumping place for garbage, pollution, and human waste. However, it is easy to see when you are out here in the open ocean how we might think the ocean is infinite. It seems so vast. But of course it isn’t.

Q: In what moment did you decide to go around the Americas and why? (Janice, JosÈ Manuel and Kiara)

I work with the University of Washington and one of my colleagues suggested I come to a meeting with some people who had this crazy plan to voyage around North & South America in a sailboat. I went to the meeting and met the crew and I realized this was a chance of a lifetime for me. I have travelled a great deal as an oceanographer and I have sailed small boats for fun. But I have always wanted to do some blue water sailing offshore. This was my opportunity to sail and do something good for the Earth at the same time.

Q: What do you recommend to protect our ocean? (Janice, JosÈ Manuel and Kiara)

First educate yourself. Take courses, read magazines, and learn all you can. Don’t just learn about the problems and challenges that the oceans are facing, learn all about the wonders of the sea. Second, start doing little things to change your habits. For example, never, never throw plastic in the sea and don’t be afraid to tell others the same. Try to drive less, and think about ways you can conserve energy. All the little things add up. And third, become actively involved in helping to raise the awareness of others. Join an environmental group, write letters to politicians, and stay informed on local issues. Remember the old advice to think globally and act locally. As Gandhi said, “We must become the change we wish to see in the world.”

Here are two questions that can have the same answer.
Q: What have you seen that you consider amazing? (Frances)
Q: What is the most impressive thing that you have seen in this voyage?

We have seen many amazing things so far: whales, polar bears, huge icebergs, storm waves fifty feet high and glorious skies full of stars. But the thing I am enjoying the most is occurring right now in the equatorial ocean: the clouds. This is the place where weather happens. Huge towering cumulonimbus clouds rise to the top of the atmosphere then spread across the sky as anvils. These are a joy to watch. (See the main photo above.) Oh yes, the stars at night are limitless.

Q: What inspired you to make this cruise? (Yolady, Irishka, Zuleyka)

I have lived a good life. I have a terrific family and my job has taken me all over the world. As an oceanographer I have been concerned with the environment my whole career. But I have not had the opportunity to “give back”, at least to my satisfaction. Around the Americas fills this wish – I can meet people and show first hand how important it is to protect our natural world. And it’s fun too!

Q: What do you need to travel around the Americas? (Evalyannit and Indira)

I am not sure how to answer this question. First, you need people with vision; people who have the idea that with this trip we can capture people’s imagination and interest. Next, after the idea, you need money. This is not a cheap trip and so you need supporters to donate money, time, and gifts (such as equipment) to support the project, and you need a crew of dedicated sailors – people, and their families, who are willing to rearrange their priorities and activities for two years in order to do this project. And then, you need people like yourself who take an interest in what we are doing, and, very importantly, in what we have to say.

Q: What is interesting and entertaining about our oceans? (Cindy and Xiomara)

The ocean is a wonderland and the more we look into it the more we can learn about ourselves. For example, did you know that a dolphin is able to hear your heartbeat underwater?…Or that the eyes of an octopus are much more advanced than our human eyes?…Or that an Albatross will travel up to twenty thousand miles to bring some food home to the family? I recommend you take the time to read all about the oceans and the creatures that live there… you will be amazed! Read, read, read.

Q: How does it feel to discover different cultures? Do you like to learn from them? (Pamela)

One of the most exciting parts of this expedition is that we get the chance to meet and talk with people of all cultures along the way. We have met Native Americans on Vancouver Island, Inuit (Eskimo) people in Alaska and Canada, and now we are entering the Latin communities from Puerto Rico, South America, Central America and Mexico. We are all thrilled and excited to meet these people, to learn from them and to learn about their lives. Everywhere we go we hear a consistent story of concern for the changing ocean and the changing climate.

Q: What made you decide to work for the environment? (Ninotchka)
You never know where your life might take you. I was born in Dallas, Texas and never had too much to do with the ocean until I began graduate school. Actually, I decided to become an Oceanographer because I wanted to study Earth science (Geology, Geophysics, or Physical Oceanography). At that time, the field of Oceanography was undergoing tremendous changes and innovations; as I learned more about Oceanography I became increasingly aware of related environmental issues and their broad geographic, cultural, economic and physical impacts. It was natural to me to try to share that knowledge with others.

Q: What does your family think about what you are doing? (Lizette)

They miss me of course. And I miss them. I miss taking my granddaughter, Chloe, to swimming practice. I always walked our dog Lucy and that was a special time. Now my family has to take Lucy in the winter. So I think they will be happy to see me come back.

Q: What has caused you the most fear? (Marisely)

The first time I was hoisted to the top of the mast in a canvas chair I was a little nervous. I go up there to tend to the climate instruments. Now I am used to it. Also I miss my family and I fear something bad might happen and I am days away at sea. But I worry far too much.

Q: How can this expedition help nature instead of just being aware of its problems? (Juan Carlos)

One of our main supporting organizations is called “Sailors for the Sea.” The goal of this organization is to convince sailors to become protectors of the sea. The hope is that if we interest sailors in ocean health and marine stewardship, they will carry the idea from their own personal choices to friends, employees, and politicians. That is one way the message can go from idea to practice. But the truth is that being aware is only the first step in actually doing something. We want to stimulate people to begin to learn about the issues, and then help encourage them to take action to help reduce human impacts on the planet. Very soon we will post information on this web site about ocean challenges and actions we can take to make a positive difference. Please check back soon, and let us know if the information is helpful.

KRISTINA ECONOMOU
Kristina sent an email to science@aroundtheamericas.org. I sent her this reply. And believe me, this is a simple question with a tough and complicated answer.

Q: If the earth had no tilt, how would the sunlight’s rays hit the Arctic Circle, and what would the seasons be like?

Okay, here goes, I hope to answer a straightforward question with not too technical an answer. Planetary geometry is always tricky and it is very difficult to explain.

First, the Earth circles the sun in an orbit that is not exactly a circle – it is an ellipse. It takes one year for the Earth to make this elliptical round trip; sometimes we are closer to the sun, and other times we are further away. It can be helpful to think of the Earth’s orbit as a flat disk or a plane, with the Earth going around the edge of the disk.

At the same time that the Earth is traveling in its annual orbit, it is spinning around an axis of rotation defined by the line between the North and South poles, and this axis is tilted. This part can be hard to visualize: at some times of the year the North Pole (and the axis of rotation) is tilted towards the sun. When this occurs, it is summer in the northern hemisphere and there is no nighttime in the regions above the Arctic Circle. Half a year later, the tilt is oriented away from the sun and the South Pole experiences constant daylight.

Your question, however, asks how this situation would be if the Earth had no tilt. If this were the case, then the

A map from the U.S. Navy’s Fleet Numerical Meteorological and Oceanographic Center (FNMOC) showing the strong currents along the coast of northern Brazil. This map depicts estimates of surface currents. The surface currents are of interest to Ocean Watch because we have to make our way southward and around the “horn” of Brazil. How accurate is this map? We are not sure, but we are concerned about the estimates of both current direction and strength. FNMOC shows coastal currents of up to 5 meters per second (m/s), or 10 knots. That is a booming current! Of great importance to us, this map shows a directional switch in surface currents to southerly just at the equator. Right now we are at 6N, 53W and we are fighting a north current of about 3 kts. Cayenne is at 5N; from there we will have several more days of counter current until (we hope) we hit the Rio Express around the horn.

axis through the north and south poles would be exactly perpendicular to the plane of the Earth’s orbit, and then there would be no difference in sunlight incident upon the polar regions except for one thing: because of the elliptical shape of the orbit, the distance from the sun to the Earth would still vary.

In general, the amount of time a given location on earth spends in daylight varies throughout the year and depends on latitude. At the equator, each day the sun can be seen just a tiny bit longer than twelve hours. As we go pole-ward from the equator, due to the tilted axis of rotation of the earth, the day length will change. For example, if we travel towards the South Pole now, in late November, the length of day would increase (as it is summer in the southern hemisphere). If we were to go towards the north, we would observe the opposite.

To get back to your question, if there were no tilt to the earth’s axis of rotation, then the Arctic and Antarctic Circles would not exist. The poles would be almost dark but the rim of the sun would always be visible for the following reason. The Sun is much larger than the Earth but it is very far away (93 million miles). Because of its size, though, a very tiny bit of the sun would be visible from both the north and the south poles. Therefore, without a tilted axis of rotation, the seasons would barely be noticeable. They would still occur, though, because the Earth would still be slightly closer or farther from the sun due to its elliptical path. Believe me Kristina, this is one tough question and with almost no references available, I have tried to give you my best answer under the circumstances.

Okay, that is the end of the questions this time. I really am looking for more and don’t be afraid to ask me whatever is on your mind. You might think your question is too simple, but remember – it isn’t! All questions are good ones.

michael@rmrco.com

Remember: all views, ideas, and comments here are ad hoc, off the cuff, minimally researched, and subject to revision at any moment.

- Dr. Michael Reynolds with photographs by David Thoreson

crew log submitted by Iridium OpenPort and Stratos

To add a comment to this story click on the comment link below the post title. Please direct your messages for the crew to crew@aroundtheamericas.org instead of submitting them here. Thanks for following the Around the Americas Expedition.

Crew Log 124 – Population: The Elephant in the Room

Nov 16th, 2009

by Dr. Michael Reynolds.

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November 16th, 2009 – From the On-Board Scientist
by Dr. Michael Reynolds

Michael Reynolds, Ph.D.

POPULATION IS THE BASE OF IT ALL
Describing population pressure as the ‘elephant in the room’ is a tired cliché. (William Safire, bless his erudite soul, warned writers to avoid clichés like the plague.) But the elephant metaphor is a good one. We all know and read about population pressure, and its pervasive impact on the finite resources of our planet, but it is clearly behind every environmental issue. When we read about pollution, climate change, fish stock collapse, ocean acidification, coral reef destruction, and most other ocean health issues, we must keep this fact in the back of our minds. In fact, as I reflect on this matter, it is not easy to point to any crisis in our immediate future where population will not be the root cause.

Lest we forget. Fifty years ago there were 2.2 billion people on this earth and it was predicted to double about

Main Photo

Image by Adam Neiman. Global water and air volume. Conceptual computer artwork of the total volume of water on Earth (blue, left) and of air in the Earth’s atmosphere (pink, right) shown as spheres. The spheres show how finite water and air supplies are. The water sphere includes all the water in the oceans, seas, ice caps, lakes and rivers as well as ground water, and that in the atmosphere. The air sphere becomes less dense with altitude, but half of the air lies within the first 5 kilometres of the atmosphere.

every 35 years; today there are 6.8 billion of us, and the doubling rate has decreased to 30 years. As the doubling rate continues to decrease, current projections are that by 2040 (in just 30 years) we will be at 9 billion. After that, we can only hope that things will level off, or even drop a bit.

A MUST-READ BOOK
Much of what I have to say today comes from a remarkable book by Dr. Jeffrey Sachs, Director of the Earth Institute at Columbia University, called “Common Wealth: Economics for a Crowded Planet.” This remarkable compendium of current facts (published by Penguin Books in 2008) offers a clear and factual description of the current state of the world from an economic, scientific, and social point of view.

A foreword by E.O. Wilson pretty well sums up this important book:”Now is the time to grasp exactly what is happening. The evidence is compelling: we need to redesign our social and economic policies before we wreck this planet. At stake is humankind’s one shot at a permanently bright future. … If we choose sustainable development, we can secure our gains while averting disasters that appear increasingly imminent. … We can still correct the course, but we do not have much time to do it.”

The famous “hockey stick” graph of the growth in world population. Note, not only are we growing more numerous. Since 1750 there has been a tenfold increase in population but also a tenfold increase in production (agriculture, goods, art) PER PERSON. That’s a one hundredfold increase in our use of the Earth for human consumption.

THE FUTURE CROWDED PLANET
So, why isn’t population control a key priority? Researchers note, as Malthus did 200 years earlier, that we have a choice between a falling birth rate and a rising death rate. In 1968 Paul Ehrlich, in his book “The Population Bomb” predicted mass starvation by the end of the 20th century due to unconstrained population growth. Faced with this prospect, it is ironic that globally, in both the U.S. and in the developing world, there are more than 1 billion overweight adults, at least 300 million of them obese, with many at substantial risk of chronic diseases, including type 2 diabetes, cardiovascular disease, hypertension and stroke, and certain forms of cancer.Two technological developments that saved us from Erlich’s prognosis: the green revolution for which Norman Borlaug was awarded the Nobel Peace Prize in 1970, and the invention of the birth control pill (or ‘the pill’).

The pill has moderate side effects, is 99% effective, and can be as cheap as aspirin. In most industrialized countries, the pill has brought the fertility rate down to about 2.1, needed for a stable population. In nations that suppress women’s rights, fertility is as high as 8.0.

Unfortunately, as E.O. Wilson put it,

“We exist as a bizarre combination of Stone Age emotions, medieval beliefs, and God-like technology.”

There are two key social processes that govern the issue of birth control. First is education, and education of women worldwide. Second is empowerment of women. In every third world country where women are educated and empowered, the birth rate falls. “In highly gender-stratified societies, the threshold level is likely to be higher than in relatively egalitarian societies. Education has been found to increase women’s levels of autonomy in decision-making, in acquiring knowledge, in gaining access to economic resources, and in interacting with a wider social circle. It is through this autonomy that education exerts an impact on fertility.”(1)

COLLAPSE AND THE EASTER ISLAND STORY

Take Home Messages

Fifty years ago population was 2.2 billion people.
Today it is 6.8 billion and of course growing.
By 2040 you can expect it to be 9 billion.
Read “Common Wealth” by J. Sachs.
Two solutions: education and birth control.

Jared Diamond is the author of “Guns, Germs, and Steel,” which explored ideas behind why some civilizations prevail over others. In his following book, “Collapse,” he examines how and why powerful civilizations seem to suddenly disappear, collapse, and in an incredibly short time. In an ABC interview he said

“Why did these ancient civilizations abandon their cities after building them with such great effort? Why these ancient collapses? This question isn’t just a romantic mystery. It’s also a challenging intellectual problem. Why is it that some societies collapsed while others did not collapse?”

“But even more, this question is relevant to the environmental problems that we face today – what if anything, can the past teach us about why some societies are more unstable than others, and about how some societies have managed to overcome their environmental problems. Can we extract from the past any useful guidance that will help us in the coming decades?”

Another time when interviewed by the National Review he said, “A blueprint for disaster in any society is when the elite are capable of insulating themselves.” Sound familiar?

The story of Easter Island in the eastern Pacific is an incredible encapsulation of the human story as it seems to be unfolding globally today. There is not room here to do justice to the relatively short time it took for the Polynesians who came to Easter Island to over-populate, denude their vegetation, exterminate their animals and fish, and finally, with the help of their religion, to crush society into “a primitive state with about 3,000 people living in squalid reed huts or caves, engaged in almost perpetual warfare and resorting to cannibalism in a desperate attempt to supplement the meager food supplies available on the island.” (2)

The history of Easter Island is a striking example of the dependence of human societies on the environment and of the consequences of irreversibly damaging that environment. It is the story of a people who, starting from an extremely limited resource base, constructed one of the most advanced societies in the world, given the technologies available at the time. The demands placed on the island environment by the people and their developments were immense. When it could no longer withstand the pressure, the society that had been painstakingly built up over the previous thousand years collapsed along with the island ecosystems.

Remember: all views, ideas, and comments here are ad hoc, off the cuff, minimally researched, and subject to revision at any moment.

- Michael Reynolds with photographs by David Thoreson
michael@rmrco.com

This crew log submitted by Iridium OpenPort and Stratos

SOME REFERENCES
World Population to 2300
http://www.un.org/esa/population/publications/longrange2/WorldPop2300final.pdf\
http://www.demographic-research.org/volumes/vol4/8/4-8.pdf

Fertility Rates:
(1) http://www.eubios.info/EJ124/ej124i.htm

Easter Island
http://www.eco-action.org/dt/eisland.html
http://www.physorg.com/news121959198.html
http://www.homepage.eircom.net/%257Eodyssey/Quotes/Life/Science/Collapse.html

Posts under ‘Science’

Welcome to the Around the Americas Science Program blog. For background on the Program, visit the overview page, or download The Science Aboard, a four-page summary in PDF format. Lastly, a complete list of Science posts is available here.

Sound Around the Americas: The Hydrophone Project

Crew Log 160 – S. Atlantic Currents: Battling the N. Brazil Current

Cloud Observations Aboard Ocean Watch for the NASA S’COOL Program

Crew Log 134 – Science Q & A

Crew Log 124 – Population: The Elephant in the Room

S/V Ocean Watch Live Tracking

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Posts under ‘Science’

Welcome to the Around the Americas Science Program blog. For background on the Program, visit the overview page, or download The Science Aboard, a four-page summary in PDF format. Lastly, a complete list of Science posts is available here.

Sound Around the Americas: The Hydrophone Project

Crew Log 160 – S. Atlantic Currents: Battling the N. Brazil Current

Cloud Observations Aboard Ocean Watch for the NASA S’COOL Program

Crew Log 134 – Science Q & A

Crew Log 124 – Population: The Elephant in the Room

S/V Ocean Watch Live Tracking

Upcoming Port Calls

Our Mission

Recent Posts

Browse the Archives

Categories

Tags

Search

Archives

Share this Blog