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Coral Reefs and Ocean Acidification

By Joan A. Kleypas and Kimberly K. Yates
Special Issue Feature from: Oceanography, Vol.22, No.4 (December 2009)

Abstract

Coral reefs were one of the first ecosystems to be recognized as vulnerable to ocean acidification. To date, most scientific investigations into the effects of ocean acidification on coral reefs have been related to the reefs’ unique ability to produce voluminous amounts of calcium carbonate. It has been estimated that the main reef-building organisms, corals and calcifying macroalgae, will calcify 10–50% less relative to pre-industrial rates by the middle of this century. This decreased calcification is likely to affect their ability to function within the ecosystem and will almost certainly affect the workings of the ecosystem itself. However, ocean acidification affects not only the organisms, but also the reefs they build. The decline in calcium carbonate production, coupled with an increase in calcium carbonate dissolution, will diminish reef building and the benefits that reefs provide, such as high structural complexity that supports biodiversity on reefs, and breakwater effects that protect shorelines and create quiet habitats for other ecosystems, such as mangroves and seagrass beds. The focus on calcification in reefs is warranted, but the responses of many other organisms, such as fish, noncalcifying algae, and seagrasses, to name a few, deserve a close look as well.

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Today we are anchored in a little bay on the west coast of the Baja peninsula. We are hiding from 30-40 knot north winds and a nasty swell that have been building for the past two days. The little fishing village at the head of the bay, San Juanico, is enveloped in a sand storm. It is a mile away and a dinghy ride in these winds would be far too wet for a visit. So, we will hide here at least for the afternoon. These north winds are called the “Baja Bash,” because any boater foolish enough to try to get to San Diego by this coastal route is bashed unmercifully. Adding to the wind bashing is the surprising cold; sea and air temperatures have dropped by 10°C (18°F) in the past two days and we have said goodbye to tropical nights.

In this report I will describe how the this sudden change in our conditions — polar fleece, sleeping bags, wool caps — is the end result of a chain of air and ocean currents that begins on a global scale with solar heating of the tropics and ends on a local scale with coastal winds and the upwelling of deep, cold ocean water.

The famous Coriolis force lies at the heart of it all. We will talk about this mysterious force then we will use a simple weather chart to demonstrate the interrelationship between the tropics, the Mid-Pacific Gyre, the Garbage Patch, coastal north winds, and, finally, coastal upwelling.

Figure 1. Current weather. A weather chart for the North Pacific ocean shows the surface pressure lines, wind barbs, and colored areas for precipitation. Our hiding spot is marked by the black circle at 26°N on the Baja coast. Labels have been added to the chart for reference. The marked features are the Mid-Pacific High (H), the North Pacific Gyre, the trade wind regimes (T), the Intertropical Convergence Zone (ITCZ), and upwelling areas along the coast (U) which are driven by the northerly winds. Click on the graph for a detailed view. Image credit: buoyweather.com.

Reading the weather chart.

The weather chart, Figure 1, was downloaded as we left Cabo San Lucas and prepared for a week-long transit to San Diego. This chart has, in one graphic, just about everything I have mentioned in many previous reports on air and ocean currents.

Symbols on the chart define the barometric pressure, winds, and areas of rain. Constant pressure lines are called isobars and, in the chart, the isobar circles define the mid-Pacific high pressure which is centered at 34°N, 150°W and has a central pressure of about 1028 millibars. The green wind barbs show wind speed and direction. Barbs are like arrows with only half their feathers. They point in the direction of the surface wind, and the number of barbs give the wind speed. One half a barb is 10 knots, a full barb is 20 knots, and one and a half barbs show a 30 knot wind. Precipitation areas are colored according to the scale on the right hand side. Rates from zero to forty-eight millimeters (2 inches) per hour are shown.

What follows here is a brief and highly simplistic description of the labeled features on the weather chart. However, before anything else you must understand the very important Coriolis force.

Coriolis force is central to understanding how winds and currents interact and none of the explanations here make sense without the most rudimentary understanding of this mysterious force.

Coriolis force is not actually a force, like gravity. In actuality it is a complicated gyroscopic reaction to the rotating Earth that pushes air or water in motion to the right of its path. It seems like a force because of its effect on motion. As an example, if water tries to move in a westerly direction, it veers off course, toward the north, as though a force was pushing it. (In the Southern Hemisphere the veer is to the left.)

The next time you are in the playground — in raising four sons I have spent quite a bit of time in the playground — stand on the merry-go-round and have someone turn it gently in a clockwise direction. Now close your eyes and take a small step in any direction. Surprise; you will not step forward, rather your foot will land to the right of where you planned. That is Coriolis force.

Figure 2. Global wind fields. A schematic of the major global wind fields. The red dashed boxes are the area of interest. The equatorial Hadley Cell (HC) is created by solar heating at the equator. Starting at the equator, warm, moist air rises to a high altitude. Winds at the surface converge to replace the rising air (the trade winds). The region of convergence is called the doldrums or the ITCZ. The rising air loses all its water as precipitation, then moves in a northwesterly direction to mid latitudes where it descends back to the surface as dry, cold (relatively) air. The area of descending air concentrates into the mid-ocean high regions. Image credit: David Jessey, Cal Poly, Pomona.

Trade winds (T). Figure 2 shows the equatorial Hadley Cell (marked by HC) which is made up of the Intertropical Convergence Zone (ITCZ), the northwest moving “westerlies” at high altitude, the descending dry air at mid latitudes, and the trade winds. 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 Coriolis force (to the right in the Northern Hemisphere and to the left in the Southern Hemisphere), the trades bend 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.

Intertropical Convergence Zone (ITCZ). The popular name for the ITCZ is the doldrums. The doldrums is a region near the equator where the north and south trade winds converge. As the Northeast and the Southeast trade winds flow toward each other they take up water by evaporation and become saturated with water. They warm in the intense tropical sun. The name doldrums means low spirits, a feeling of boredom or depression which is well suited to these conditions.. Clouds in this region reflect the high humidity and the sudden release of energy that accompanies the rainfall.

When the winds meet (converge) they rise up into the atmosphere and lose their water by precipitation. The doldrums is the narrow band of towering clouds, squalls, and high humidity that is formed from the convergence. Because of differences in ocean coverage between the two hemispheres, the trade winds do not converge exactly at the equator, but usually they between two and seven degrees north approximately. In Figure 1, the doldrum band is clearly identified by the high precipitation region around +5°N. The trade winds and the doldrums were discussed in a previous report.

Mid-Pacific High (H). Coriolis forces concentrate the dry, descending air of the Hadley Cell into mid-ocean high pressure areas. In the Pacific Ocean this is the Mid-Pacific High. Figure 1 shows the Mid-Pacific High centered around 30-40°N latitude. The center of the high and its central pressure vary in time according to season and in response to other processes such as the Jet Stream to the north.

As a rule, air flows from high pressure toward low pressure and we expect to see winds flowing away from the high. However, Coriolis force pushes the flow to the right, so as the winds blow away from the high they are turned to the right. As a result, the winds around the high blow in a clockwise direction (see the green wind barbs) around the high cell.

Note; the same thing happens in reverse for a hurricane. Air that is heated by a warm ocean forms a low pressure center. As air flows toward the low it is turned to the right and begins a counter-clockwise vortex. As the vortex becomes stronger, winds increase and the storm intensifies to become a hurricane.

North Pacific Gyre, the Garbage patch. Around the Mid-Pacific High, the clockwise winds blow across thousands of miles of ocean. There is a small amount of friction between the air and the water so, by friction, the winds try to push the ocean surface in the same circle. However, water flow has the same Coriolis force to the right that air does, so the resulting ocean currents, on the surface, are toward the high center (there is no shame in doodling these directions on a piece of scrap paper).

Floating objects, pollution, garbage, and plastics are carried with the resulting ocean currents, and over time they spiral into the high. The garbage is captured in the gyre and remains there for years. The famous “garbage patch” has attracted considerable attention lately. At last accounting the garbage patch covered an area roughly the size of the United States. In Figure 1 the North Pacific Gyre roughly occupies the area shown by the dashed line.

Coastal winds and the Baja Bash. Finally, we come to the important coastal upwelling region on the west coast of the U.S.A. and Mexico. As I write this report Ocean Watch is hiding in a little bay called Bahia San Juanico on the west coast of the Baja peninsula.

You can see from the isobars and the wind barbs in Figure 1 that for the entire trip up the coast Ocean Watch has sailed against winds of 20 to 30 kts. These winds have been blowing across at least 500 miles of open ocean and over such a long distance a large ocean swell can develop. They have and we can vouch for it.

This route up the Baja coast is well known to sailors, and is avoided as a matter of course. The ride is notoriously known as “The Baja Bash.” It’s fun to sail down to Mexico; not so much fun coming home.

Last night the isobars tightened more and the head winds increased to above 30 knots. Ocean Watch was riding over the waves with ease, but for the crew the ride was not comfortable. Our mainsail was pulled down into its third and final reef, and as conditions worsened, we decided to hide in this little bay, at least until tomorrow.

Along with the winds, waves and the bashing, it has become cold. For the first time in months we are wearing our polar fleece jackets on deck, at least at night. The air temperature has dropped from 30°C (86°F) to 14°C (57°F), and in the wind over the ocean, that is bone chilling.

Coastal Upwelling (U) and Sea-Surface Temperature

The reason the air is cold is that the ocean is cold. We are in the regime of coastal upwelling. The upwelling area, see ‘U’ on the chart, extends up the coast of California and is one of several upwelling regions around the world. My previous report on upwelling and El Niño talked about upwelling around the world. Figure 3 tells the story for the California coast. Since leaving Puerto Vallarta the sea temperature has dropped from about 25°C (77°F) to 15°C (59°F) and most of that drop occurred in just the last few hundred miles, from Cabo San Lucas to our current anchorage in Bahia San Juanico.

Figure 3. SST on the coast. A map of the sea surface temperature (SST) along the coast of Baja. The anchorage at San Juanico is shown marked with “OW” and the Cabo San Lucas at the end of the Baja peninsula. The temperature decrease along the Baja western shore is a result of coastal upwelling, a response to the strong northerly coastal winds. Click on the image for a larger view. Image credit: buoyweather.com.

Coastal upwelling is brought about by north winds and Coriolis force. As discussed above, wherever the wind blows, there is a tendency for the resulting current to flow to the right of the wind. (Even icebergs flow about 20° to the right of the wind.) The wind blows along the coast and the surface water moves offshore. Something has to replace the water leaving the coast and that is water from below; cold fertile water from below the thermocline. The thermocline was introduced in science report 24 April 2010).

Finally…

The world and its workings cannot be taken in pieces. Everything in Nature, the winds, currents, animals, chemicals, and even the motion of the stars, play a role in how this grand machine plays its song. In this simple description I wanted to show how the cold water on our coast, the coastal winds, the oceanic pressure fields, the trade winds, and the Sun’s heat in the tropics (heat from the Sun drives the whole engine) all relate to each other. That is the lesson we must remember. Tinker with any tiny piece of the whole at a risk to us all.

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

Michael Reynolds, Ph.D., RMR Company

In Costa Rica Ocean Watch took on two new instruments: a second thermosalinograph for underway measurements of surface water temperature and salinity, and a profile instrument called a CTD for conductivity-temperature-depth. The CTD has a high-precision pH sensor. The CTD is lowered by a rope so a profile of the upper ocean structure can be obtained. The profile is necessarily shallow, but still reveals interesting near-surface structure including solar heating layers, mixed layers, and a strong thermocline. We will use the profiles to demonstrate many important concepts in physical oceanography.

Layers in the ocean

The waters of the oceans are layered and the structure of the layering tells oceanographers a great deal about the ocean currents, the origins of the water and its fate. To discuss ocean layers one needs to know about density. Density of a substance is the weight of a set volume of that substance. For example, a cup of mercury weighs much more than a cup of water because the density of mercury is about 14 times the density of water. Oil floats on water because oil density is slightly less than water.

In the ocean, the water density is determined, primarily, by two factors: the temperature and the salinity. As the temperature is increased the water becomes lighter. Salinity is the amount of salt in a volume of water. Oceanographers measure salinity in parts per thousand and use the symbol “°/_°°“. The average salinity in the ocean is about 34°/_°°, meaning 3.4% by volume. The saltier water, e.g. higher salinity water, is heavier. That is, it has a greater density. Density is a measure of weight for a specific volume. For comparison, the salinity of water in the Persian Gulf can reach more than 40°/_°°, while the salinity in a river-fed bay might be a brackish 25°/_°°.

Physical Oceanography pays particular attention to density and to the layers that form in the sea. The interface between layers is important because they form barriers to exchange between layers. There are thousands of examples and we certainly will not be covering them in detail here. I want to discuss instead the structure of the water we are currently transiting, where coastal upwelling breaks down the layers and brings nutrients to the surface thereby fueling the high productivity that supports a fishing industry.

The ocean surface is a region where layers are complex and variable. This is where the ocean and atmosphere exchange heat, moisture (rain and evaporation), and gases (approximately one-third of all CO₂ emitted into the atmosphere by humans is absorbed into the ocean through its surface). Figure 2 shows that the top of the ocean in our current location off the Mexican coast is a warm layer over a deeper layer of cold water. Our cast does not go deep enough to register deeper layers, but the very strong thermocline is apparent.

Life in the ocean depends on the plants. In a pyramidal fashion, called the food chain, the plants (algae) come first and are followed by plant eaters such as shrimp, krill, shellfish, and tiny fishes. Then, eating these small creatures are larger fish, squid, and the other carnivores. Finally come the large fish, the tuna, swordfish, dolphin, and porpoises. The food chain depends on the plants, and the plants grow where there is sunlight and nutrients. Productivity is a measure of the rate of creation of carbon in the food chain. Satellites can measure ocean color and determine the amount of chlorophyll, and from that estimate the productivity in different regions. Murkiness in the water is related to the concentration of algae.

Plants grow in the ocean layers where there is ample sunlight, that is, near the surface. The euphotic zone is the top layer of water where there is enough sunlight for photosynthesis. The rest of the food chain follows and life in the upper ocean is good until the nutrients run out. Nutrients for ocean plants are not much different than nutrients needed in your garden. Plants need nitrogen, phosphorous, iron, and other ingredients. If any one of these runs out, productivity comes to a halt. As the food chain prospers there is a slow sinking of nutrients to the bottom. Fish and plants die and animals excrete waste, creating a steady snow of particulates, falling downward, and importantly, through the thermocline barrier. Indeed, the falling debris is called “marine snow” and it is reported by deep divers in all the world’s oceans.

Figure 3. Wikipedia describes marine snow as follows: “In the deep ocean, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. Its origin lies in activities within the productive photic zone. Consequently, the prevalence of marine snow changes with seasonal fluctuations in photosynthetic activity and ocean currents.” Image credit: Planktos Science

When the snow falls through the density barrier, in this case the thermocline, it is removed from the surface water and cannot provide nutrients for more algae production. The thermocline is an interface that bars mixing of water. When the nutrients run out the whole food chain is diminished, the water clears and turns blue to the observer, and the euphotic zone becomes much deeper. Productivity will increase only when more nutrients are injected into the euphotic zone, and a major way this happens is by upwelling.

We have described upwelling in previous reports. From the point of view of oceanography, upwelling is caused when the mixed layer is pushed offshore by the winds (along with gyroscopic forces called Coriolis forces) and deeper water moves shoreward lifting the thermocline up to the surface where it can be broken by wind and wave turbulence. With the thermocline broken deeper water can mix to the surface.

Measuring the ocean from Ocean Watch

This spring, Ocean Watch was sailing out of an El Niño region and up the west coast of the U.S., one of the world’s productive upwelling regions. For an ersatz oceanographer like me, it is just too frustrating to be sailing over such fascinating water without trying to look under the surface. Therefore, while I was back in Seattle in April I contacted my friends at Sea-Bird Electronics, Inc. and without hesitation they agreed to loan us two instruments. Sea-Bird is one of the most respected names in oceanographic instrumentation and we are deeply thankful for their support.

First they provided us with an instrument called the thermosalinograph. A thermosalinograph is a device that sucks seawater through a fitting below the water line in the boat’s hull, through a special sensor, and back out to sea. It continuously measures the temperature and salinity of the water as the ship travels. Other sensors, such as oxygen, pH, and opacity can be included. Our SeaKeeper thermosalinograph, described in many of our reports, has operated since we left Seattle. After such a long time we had some concerns about calibration drift, i.e. the accuracy of our measurements. The Sea-Bird thermosalinograph was connected into the same pumping system as the SeaKeeper sensors and it provides a check on any error from the SeaKeeper system.

And I am happy to say that the two key measurements, salinity and temperature, agree nearly perfectly on the two instruments. We are pleased and reassured by this result.

CTD profiles from Ocean Watch

Ocean sub-surface density profiles are measured by an instruments called a CTD. The name stands for conductivity-temperature-depth, the primary sensors. The CTD is the heart of any oceanographic research cruise. Other optional sensors for pH, oxygen, and other chemicals are often included with the package The Ocean Watch probe has a pH sensor (see Figure 2) so it is possible see differences to pH through the surface layers. Figure 1 shows the SeaCat being deployed and Figure 2 shows the profile of salinity, temperature, and pH for a typical cast. A discussion of the CTD program on Ocean Watch is a topic for a future report.

Michael Reynolds, Ph.D., RMR Company

Volcanic ash from Mt. Eyjafjallajökull in Iceland is disrupting air travel. Could it also disrupt the climate? “Ahh,” say the skeptics, “that should solve the global warming issue for awhile.” Any excuse for business as usual. But the fact is that this eruption, and the aerosols they disperse into the atmosphere, are small by comparison to previous events. Any global dimming, and associated temperature decrease, they produce is a short-term adjustment to the continuously increasing global temperature. Aerosols do, in fact, counteract the warming from increased greenhouse gasses, but they are short lived and they can never completely stop the warming process. We review aerosols, global dimming, and nuclear winter. The measurement program on Ocean Watch is discussed.

What is an Aerosol?

Very simply, an aerosol in the atmosphere is any particle small enough to be kept aloft by air currents. Aerosols include water droplets (clouds are aerosols), ash, dust, salt crystals from ocean spray, and smoke of any kind. The smoke from the burning of tropical rain forests is a major source of aerosols as is automobile exhaust. Aerosols largely come from man-made sources from many countries and also some natural sources. African dust and its impact on climate and the health of the West Indies (including corals) is of growing concern.

In general, aerosols are continuously falling to back to Earth. How fast they fall depends on their size, shape, and density. Nevertheless, when compared to other processes, such as increasing CO₂ or orbit changes, their impact on climate, weather, or human activities is short-term (days to months) and is generally localized near major sources rather than being spread globally.

Some major volcanic aerosol emissions, such as Mt. Pinatubo, are injected high into the stratosphere and are carried around the world. But this is not the norm. The effect of aerosols on climate change is highly uncertain compared to what we know about the effect of “greenhouse gasses”. The ability of global climate computer models to describe or predict climate change is limited by our ability to define aerosol effects.

Mt. Eyjafjallajökull, Iceland: today’s volcano

On about April 14, Mt. Eyjafjallajökull, Iceland, began a major eruption. The volcano had been venting several weeks prior to the eruption. Extreme Icelandic cold caused the hot emission to cool into a gritty ash plume which was carried by high winds right over Europe (see figure below). The eruption is far from finished, and at this writing has kept much of Europe land-bound. New mini-eruptions raise concerns about longer-term damage to world air travel and trade.

As volcanic eruptions go, Mt. Eyjafjallajökull is not a big event. It pales in comparison to past climate-cooling eruptions. Eyjafjallajökull’s ash has reached a height of 55,000 feet, according to press reports. By contrast, ash from the 1991 Mt. Pinatubo eruption, one of the biggest in the 20th century, reached 78,740 feet.

Overall, Pinatubo, which is in the Philippines, ejected 14 to 26 million metric tons of sulfur dioxide that produced a significant global cooling effect for a few years. Following the eruption, this temporary cooling also slowed sea level rise rates temporarily. Nevertheless, in an April 18 news article (Headland SatNews) it was reported “Modern Europe has never seen such a travel disruption. Air space across a swath from Britain to Ukraine was closed and set to stay that way until Sunday or Monday in some countries, affecting airports from New Zealand to San Francisco. Millions of passengers have had plans foiled or delayed. Activity in the volcano at the heart of this increased early Saturday, and showed no sign of abating. ‘There doesn’t seem to be an end in sight,’ Icelandic geologist Magnus Tumi Gudmundsson said on Saturday.”

Climate Change, Global Dimming and Nuclear Winter

The setting sun in Los Angeles turns different shades of orange because the aerosols, from traffic mainly, filter incoming sunlight. Refer to Figure 2 and imagine the atmosphere as a dirty window. The solar radiation that strikes the Earth’s atmosphere (Referred to as the “top of the atmosphere radiation,” or TOA.) is measured by satellites and solar observatories and is well known.

As the radiation penetrates the atmosphere it interacts with air molecules, ozone, and aerosols. Some of the radiation passes through without interaction; this is the sometimes orange sun you see in a clear sky. Some of the sunlight interacts with air molecules and is scattered in different directions. (Think of light as a stream of individual particles, called photons, and think of collisions between the photons and aerosol and air molecules as a game of billiards.) Some of the scattered photons are sent back to space. Therefore, aerosols reduce the heating effect of solar radiation and, in a small way, help to cool our climate and offset the warming effects of greenhouse gasses (CO₂, methane, ozone).

On the other hand, aerosols can add heat to the atmosphere which partially offsets the cooling effect. As the Earth heats up from the sun, it radiates heat back to space. Aerosols absorb some of the heat radiation and reduce the amount of heat radiation escaping out to space. This is the same heat-blocking effect attributed to greenhouse gasses, and in this way aerosols can have a heating effect on global climate.

Nevertheless, the net effect of aerosols is to reduce the rate of global warming from greenhouse gasses. Does this mean we should all go build fires and drive our cars? No, because the offset that aerosols make on all of all these activities is smaller than the impact those activities make on global warming. Models and data now show that aerosols reduce the increase in global temperature by a factor of approximately 50% (there is uncertainty in the actual amount). So, they slow down the process but do not stop it. And they create pollution and effect health at the same time.

Global dimming is a term used for the reduction of sunlight as it passes through the atmosphere. When aerosols are concentrated the sunlight is reduced, heat reaching the surface is reduced, and global warming is reduced.

The TOA (top of the atmosphere) radiation (Figure 2) is scattered and absorbed during its passage through the atmosphere. The fraction of sunlight reaching the Earth’s surface depends on two things: the aerosol loading and the angle of the sun. As the sun nears the horizon the beam cuts through more and more atmosphere thickness and the impact of the aerosol increases. This explains why the setting sun turns different colors in a smoggy or hazy sky.

A numerical measure of the aerosol loading factor is the “optical depth.” Optical depth is a logarithmic measure like the Richter scale for earthquake intensity and pH for acidity. The total optical depth is related to the total reduction in sunlight reaching the Earth’s surface. When the sun altitude is 60° above the horizon and the optical depth is 0.2, roughly 82% of incoming radiation reaches the ground. Alternately, when the optical depth is 1.0, as under thin cloud, only 13% reaches the ground.

The total optical depth is the sum of effects from ozone, air molecules, and aerosols. When all other contributions are removed from the measure the resulting number is the “aerosol optical depth,” which is the dominant term for solar radiation. As aerosol optical depth is increased due to particles from anthropogenic sources, the atmosphere becomes less clear. This is easily observed by eye as a haziness in the atmosphere. The sky looks whiter rather than sky-blue, and visibility is reduced, i.e. distant objects can no longer be seen.

Excessive aerosol optical depths are found around and downwind from major urban areas. For example the Ohio River Valley, the northeast U.S. coast, Los Angeles, Phoenix, Mexico City, and Beijing are regions with high optical depths over five-hundred to one-thousand mile distances. These plumes of aerosol are released near ground level where they are often effected by local weather. For instance, aerosol concentrations at low levels and are drastically reduced from rainfall (hence the clear skies following a rain storm).

Figure 5 is a graph of optical depth in recent history showing volcano events in 1982 and in 1991. The increase in optical depth is apparent and the graph shows that the effects of major events last only a couple of years. Of interest is the fact that the optical depth since 1981 and especially after 1991 has been dropping by a considerable amount. The decrease is attributed to increased clean air legislation in North America and Europe. Reducing aerosol optical depths means increased global warming.

Will Mt. Eyjafjallajökull significantly reduce global warming?

No.

The Union of Concerned Scientists recently published an opinion on how the Iceland volcano might affect climate change. The headline was “Iceland Volcano Eruption Too Small to Have Significant Climate Effect, Science Group Says.”

“Even if a volcanic eruption were big enough to temporarily cool the planet, heat-trapping carbon dioxide from burning fossil fuels and destroying rain forests (burning and decomposition) would still pose a significant threat, says UCS climate scientist Brenda Ekwurzel. ‘Unlike volcanic ash that will leave the atmosphere within a few months or years, carbon dioxide remains there for decades and even centuries,’ Ekwurzel said. ‘Overloading the atmosphere with carbon dioxide has put us on the path toward a long-term warming trend, so we really can’t pin our hopes on occasional volcanic eruptions to solve the problem.’

“The short-term cooling effects of the Mt. Pinatubo eruption are long gone, and global warming is continuing unabated, she said. ‘In fact, we just experienced the hottest decade on record.’”

Aerosol Measurements from Ocean Watch

The Around the Americas voyage is collaborating with the Joint Institute for the Study of the Atmosphere and Ocean of the University of Washington to support a NASA project to measure the sun’s brightness at sea level and to record the aerosol optical depth along the coast of the Americas. These data complement ongoing observations from a network of continental and island stations. The observation network is called Aeronet. All of these measurements together combine to provide validation points for long-term NASA satellite measurements of optical depth on the worldwide scale.

NASA is using satellites to measure optical depth by a different method: by measuring the radiation reflected back to space. NASA operates a number of satellites to take images of the Earth, and then use the images to estimate the brightness of the Earth-atmosphere. This brightness, as measured from space, is related to the optical depth that a sun photometer measures directly at the surface.

The particular value of the sun photometry measurements from the Ocean Watch AtA voyage is that they are made near the coast where satellite measurements area difficult and where validation of the satellite data is particularly important.

Michael Reynolds, Ph.D., RMR Company

Report 1 on El Niño presented a few features of the coastal upwelling along the west coast of the Americas, a gentle introduction to a complex global shift in atmospheric and oceanic circulations and to the local effect called El Niño. In this report we will continue that discussion by describing the large circulation shift called the Southern Oscillation and how that relates to El Niño so that the entire ocean-wide phenomenon is called “El Niño/Southern Oscillation” or ENSO.

Imagine a bathtub

Before we start this discussion let us try a thought exercise to help vision the features of ENSO. Imagine the entire Pacific Ocean is in your bathtub (assuming you are one of the lucky people in the world who has a bathtub). At one end of the tub we place a powerful fan, like the one used to simulate wind in the movie “The Perfect Storm.” That had to be a big fan, right? Now run the fan at full force so that, at the far end of the tub, water is piled up, and at the upwind, fan end the water level is down. The friction of the wind on the surface pushes the water down wind so there is a slope. As long as the fan roars away the water level has the upward slope and the system is in equilibrium, another word for steady.

Do you have that vision of the bathtub with water set up at the far end? Now, shut off the fan. What happens? The surface water runs down hill and the surface becomes level. This, to the first order of simplicity, describes El Niño-Southern Oscillation, or for short, ENSO. Of course reality is much more complex than water in a bathtub.

Now, think of the bathtub as the equatorial Pacific Ocean, including Peru, Central America, New Guinea, and Northern Australia. The wind machine becomes the trade winds which force the surface waters toward the equator and, more importantly, pushes them toward the west. The result is that, under normal conditions, the western side of the Pacific is around 4 meters higher than the coast of South America.

As we have said many times, El Niño is not an isolated weather event, local to Peru and South America. It is not even localized to the North and South American continents. Rather, it is a re-adjustment to the global ocean and atmospheric circulations whereby weather patterns are disrupted, often in extreme ways. In this report I want to describe a few of the major global patterns in an attempt to give a clue, just a clue, to the magical complexity of this regular event.

Reader, stay with me now. A linked chain defines the most important features in oceanic circulation: The figure above shows the Pacific Ocean circulation features for normal conditions. (a) Solar heating: Solar radiation at the equator is intense and heats the sea surface. (b) Convection: The sea surface heats the atmosphere. Hot air rises and therefore, along the equator, the air rises high into the atmosphere. (c) Equatorial convergence: Low level air flows toward the equator to replace the rising air. (d) Trade winds: The equatorward flow is turned westward by the rotation of the Earth. (e) Mid-ocean high cell: Moist air rises from the equator, rains out all of its moisture, and sinks as dry air at around 30 degrees north and south of the equator. Large oceanic cells of high pressure with circular air flow are formed. (Clockwise flow in the northern hemisphere and counter-clockwise in the southern hemisphere.) (f) Upwelling regions: The northern hemisphere high cell drives northerly coastal winds along the west coast of North America. Ocean currents move to the right of the wind (see the previous report) which creates coastal upwelling. Along Peru, the trade winds cause southerly coastal winds (from the south) which drive offshore currents and create a trade wind driven upwelling. (g) Warm Pool: Intense solar heating, the trade winds, and resulting ocean circulations form a massive region of very warm sea surface temperature (SST) in the tropical western Pacific Ocean. This is one of the most important features in global atmospheric dynamics; we will discuss it further in the next section.

Figure 1. A NASA derived map of the global sea surface temperature (SST) for July of 2001. This was a normal, e.g. non-El Niño/Niña year. Several features, which are discussed in this report, are shown. The trade winds deliver a broad westward force across the equatorial Pacific. The trades and associated ocean circulations contribute to the massive pool of warm water in the western Pacific, the “warm pool,” and the coastal winds along North and South America lead to the upwelling regions, notably on the California and Peruvian coasts. (Click on the map to bring up a high resolution version.) Image credit: NASA

The Warm Pool, the firebox for the atmospheric engine

Figure 1 shows the features we discussed above on a real satellite-derived map of global sea surface temperature. The yellow color denotes very warm surface water and the tropical western Pacific warm pool region stands out as a huge region. The official definition of the warm pool is water that is above 28 degrees Centigrade (about 82 deg F). Typically the size of the warm pool is greater than the United States.

Inside the warm pool convective clouds, cumulo-nimbus towers, extend to the stratosphere where their tops are sheared off by the strong westerly (from the west) winds above. The rising air, having come across thousands of miles of ocean, is full of water which falls from the clouds. The rainfall in the warm pool is typically 3-5 meters (9-15 feet) per year making this one of the rainiest places on the Earth.

Exactly how and why the warm pool forms as intensely as it does is not well understood. The physics of the warm pool is still a subject of research and debate. But scientists all agree that if one thinks of the atmosphere as a steam heat engine (hot, moist air rising and cooler, dry air falling) then the warm pool would be the “hot box” for the entire world’s atmosphere.

Now, turn off the trade winds

Think back to the bath tub analogy. When the fan stops blowing, the water level in the tub relaxes back toward level. This is what happens in the Pacific in an event called the Southern Oscillation. The Southern Oscillation has a period of from 3-6 years. It is called an oscillation because the winds cycle in a back-and-forth way. On one part of the oscillation, the trade winds drop considerably. Sometimes the wind direction changes from easterly (from the east) to westerly in what is called a westerly wind burst because it tends to come on suddenly.

When the trade winds drop, the ocean surface across the entire ocean begins a slow process of adjustment, whereby the sea level changes (down in the west, up in the east) as vast amounts of hot equatorial water flow eastward, toward Peru. The process is very slow because the surface layer is thin, and the distances are thousands of miles. Gyroscopic forces from the rotating Earth focus the flow onto the equator.

The warm pool is part of this adjustment, and it is carried eastward into the center of the Pacific Ocean. It carries its rainfall with it, and desert islands in the central pacific, such as the Galapagos, experience huge rainfall increases.

Figure 2. A map of the SST anomaly (difference of current SST from a 30-year average) during the peak of hurricane season, August-September-October, for 1987. When discussing a quantity such as rainfall or sea surface temperature as they relate to climate, it is much easier and more forceful to consider the anomaly rather than the actual quantity. We say rainfall is 6 cm above “normal,” or that daily maximum temperature is above the long-term average temperature. In discussions on ENSO the anomaly of a quantity is the difference between quantity and the average over the last thirty years (or some such reasonable long length of time). In the above figure for SST, the white areas are not statistically different than the long term average, e.g. no change. Yellow and red areas are warmer water and blue regions are colder. The scale shows the amount of change from the long term average. The Niño 3.4 region, part of the official definition of El Niño is shown. Image credit: NOAA/ESRL.

A Definition of El Niño

A question one might ask is how do we know that an El Niño is here? What temperature, sea level, or other indicator is needed to say, officially, that the ENSO is happening? Or how do we know that it has gone away? The official definition of El Niño was proposed by Kevin E. Trenberth (one of our leading researchers in climate change) of the National Center for Atmospheric Research as follows:

If a five-month running mean of the surface temperature anomaly in the Niño 3.4 region (5N-5S, 120-170W) exceeds 0.4 degC for 6 months or more.

Kevin E. Trenberth, “The definition of El Niño”, Bulletin of the American Meteorological Society, Vol 78 (12), pages 2771-2777, December 1997

The Niño 3.4 region is shown in figure 2. The anomaly at this time was well above the threshold. At the other end of the Southern Oscillation, when the trades are strong, the situation is called La Niña, or the baby girl.

Figure 3. A recent global map of the SST anomaly for the month of March 2010. By the definition above, El Niño is still in progress though diminishing. The most warming at this time is in the central Pacific. Image credit: NOAA/NCEP.

Hurricanes, El Niño, and Modiki El Niño

Not all El Niño events are created equal when it comes to their impact on Atlantic hurricane activity. Differences in El Niño events are described by Dr. Jeff Masters. The global effect of an El Niño depends on how far the warming travels across the Pacific Ocean. If the strong warming travels all the way across the Pacific to Peru, the pattern is called an Eastern Pacific Warming (EPW) pattern. EPW conditions occurred, most recently, during the El Niño years of 1997, 1987, and 1982.

In contrast, more warming occurred in the Central Pacific during the El Niño years of 2004, 2002, 1994, and 1991. The warm pool migration seems to stall in the central Pacific. This pattern is called Central Pacific Warming (CPW).

A recent paper published in the journal “Science” attempts to explain why some El Niño years see high Atlantic hurricane activity. “Impact of Shifting Patterns of Pacific Ocean Warming on North Atlantic Tropical Cyclones”, by Georgia Tech researchers Hye-Mi Kim, Peter Webster, and Judith Curry, theorizes that Atlantic hurricane activity is sensitive to exactly where in the Pacific Ocean El Niño warming occurs.

Over the past 150 years, hurricane damage has averaged $800 million/year in El Niño years and double that during La Niña years. The abnormal warming of the equatorial Eastern Pacific ocean waters in most El Niño events creates an atmospheric circulation pattern that brings strong upper-level winds over the Atlantic, creating high wind shear conditions unfavorable for hurricanes. Yet some El Niño years, like 2004, don’t fit this pattern. Residents of Florida and the Gulf Coast will not soon forget the four major hurricanes that pounded them in 2004–Ivan, Frances, Jeanne, and Charley. Overall, the 15 named storms, 9 hurricanes, and 6 intense hurricanes of the hyperactive hurricane season of 2004 killed over 3000 people–mostly in Haiti, thanks to Hurricane Jeanne–and cost $40 billion in damages.

During EPW years, when the warming occurs primarily in the Eastern Pacific, near the coast of South America, the resulting atmospheric circulation pattern creates very high wind shear over the tropical Atlantic, resulting in fewer hurricanes.

On the other hand, CPW years had lower wind shear over the Atlantic, and thus featured higher hurricane activity than is typical for an El Niño year. One of the paper’s authors, Professor Peter J. Webster, said the variant Central Pacific Warming (CPW) El Niño pattern was discovered in the 1980s by Japanese and Korean researchers, who dubbed it modiki El Niño. Modiki is the Japanese word for “similar, but different.”

Michael Reynolds, Ph.D., RMR Company

OCEAN WATCH departs from Los Sueños, Costa Rica today. We will be sailing into what is left of the 2009-2010 El Niño event which is considered to be one of the most intense of the past decade. We have new instruments to help us define and record the structure of the surface waters through which we will pass. The coastal waters off of the west coast of the Americas, and the atmospheric boundary above, are extremely important for local economies and are crucial for our understanding of climate changes. In this and following reports we will endeavor to explain some of the complexity of ocean and atmospheric circulations as they relate to our observations.

Peruvian Fisheries

One of the world’s richest fisheries is off the coast of Peru. In most years winds from the southeast, in a process called “upwelling,” push warm surface water away from the coast. In its place, upwelling brings cold water rich in nutrients to the surface. (See the left map of sea surface temperature below.) The nutrients provide nourishment for the microscopic plants know as plankton. Plankton normally provide food for a vast community of anchovies and other fish. The fish in turn supply food for seabirds. Not only is the fish catch economically important, the harvesting of bird excrement (guano) provides a supply of valuable fertilizer.

Every few years, typically five years, the pattern of air circulation over the equatorial Pacific changes in a way that shuts down the coastal upwelling. When the upwelling stops, surface waters warm considerably from less than 60 to over 80 degrees F (15-35 degC). Everything that depends on the overturning suffers catastrophic decline: nutrient concentration declines which reduces plankton productivity followed by the collapse of the fishery. Birds die by the thousands. The natives of Peru knew this regular event and the named it “El Niño” for the Christ child.

Normal Years	El Niño 2010
This map shows the sea surface temperature (SST) over the world’s oceans for a normal year. The dashed boxes show regions of upwelling where overturning of the surface water brings up nutrients. The deeper water is colder and thus one sees that the coastal water SST is much cooler than that offshore. The fertile waters drive huge local fisheries.	This map shows global SST for February 2010, an El Niño year. Notice the waters off Peru are now warm and the upwelling region has moved south and offshore. The waters off of Costa Rica are quite warm too. The upwelling area off of North America is still active if not broader. This SST map is for February 2010 and the El Niño event is coming to an end.

Some biologists fear that the overfishing of the anchoveta by humans, plus the eating of anchovies by large fish and seabirds, combined with the injurious effects of an intense El Niño episode, like the one in 1997-98, could reduce the anchoveta stock to such critically low numbers that recovery could be difficult. The 1972-73 El Niño caused a serious drop in the fish catch which took years to recover. Since then, the Peruvian government has worked hard to regulate fishing in their territorial waters. Fortunately they have been successful, and the fishery has recovered from even severe El Niños like the one in 1988-1989.

El Niño: a local effect of a global event

If we would please society we must be prepared to be taught many things we already know by people who do not know them!
Nicolas Chamfort

I want to explain this very interesting physical process, but how? The subject is so well researched and so well explained in thousands of articles, books, and web pages that I cannot imagine how I could contribute to that infinitude of knowledge available to people of every degree of expertise. Nevertheless, with Chamfort’s advice in mind I shall forge ahead.

By now most people have heard of El Niño, if only to know the name refers to some kinds of abnormal weather. The definition of “abnormal” varies widely with geography, though. For people who live in Indonesia, Australia, or southeastern Africa, El Niño can mean severe droughts and deadly forest fires. Ecuadorians, Peruvians, or Californians, on the other hand, associate it with lashing rainstorms that can trigger devastating floods and mudslides. Severe El Niño events have resulted in a few thousand deaths worldwide, left thousands of people homeless, and caused billions of dollars in damage. Before the winter of 2010 residents on the northeastern seaboard of the United States credited El Niño with milder-than-normal winters (and lower heating bills) and relatively benign hurricane seasons. After the past severe winter in the Northeast US, all bets are off and one can say simply that weather is chaotic and extreme.

If you ever wanted to have an appreciation of how beautifully interconnected Nature can be, taking into consideration all the workings of weather and climate, as well as the responses of the biological sphere and concomitant chemistry, take a moment to consider the intricacies of El Niño. Back in the 70’s, before we had global warming to blame, just about any extreme weather event, drought in California, floods in the midwest, heavy rain in California, intense hurricanes, or anything else you might mention was blamed on El Niño.

On 10 April, 2010 the headlines were different: “Landslides and floods kill 200 people as Rio de Janeiro drowns under ELEVEN inches of rain in just 24 hours.” The death toll following the heaviest rains in Rio de Janeiro’s history was set to soar above 200 after a new mudslide hit neighbouring slums. The latest landslide surged into a rain-sodden hillside shanty town in Rio’s neighbouring city of Niteroi, engulfing at least 40 homes in a cascade of mud. The ground gave way in steep hillside slums, cutting red-brown paths of destruction through shantytowns. Heavy flooding in some places and terrible droughts in others result from a readjustment in circulation patterns caused by the El Niño and associated events.

Note that the disruptions from the El Niño occur every 4-6 years and last 1-2 years. These events are superimposed on the global climate change which is on a scale of centuries.

But El Niño is a local manifestation of a global change in weather patterns. As described above, the name was coined in the late 1800s by fishermen along the coast of Peru. Today, the term no longer refers to the local seasonal current shift but to part of a phenomenon known as El Niño-Southern Oscillation (ENSO), a continual but irregular cycle of shifts in ocean and atmospheric conditions that affects the entire world. El Niño has come to refer to the more pronounced weather effects associated with anomalously warm sea surface temperatures interacting with the air above it in the eastern and central Pacific Ocean. Its counterpart–effects associated with colder-than-usual sea surface temperatures in the region–was labeled “La Niña” (or “little girl”) as recently as 1985.

The OCEAN WATCH crew certainly noticed the very warm water as they sailed along the Peruvian coast to the Galápagos and on to Costa Rica. We expected the cooler waters and upwelling, but water temperatures were well above 28 degC (82 degF) which made cabin conditions very unpleasant. The dormant fishing fleets lined the docks and the ports were quiet.

The shift from El Niño conditions to La Niña and back again takes about four years. Understanding this irregular oscillation and its consequences for global climate has become possible only in recent decades as scientists began to unravel the intricate relationship between ocean and atmosphere. Although meteorologists have long been forecasting daily weather based on atmospheric measurements taken around the world, they had relatively little information about conditions in many parts of the world’s oceans until the advent of arrays of fixed, unmanned midocean buoys in the Pacific Ocean and orbiting satellites.

But technological advances were not the only key to understanding. Atmospheric and oceanographic researchers, after years of independent inquiry into the basic workings of air and sea, have at last joined forces. An elegant synthesis of these two fields of research now enables climatologists and oceanographers to construct theoretical models to simulate and predict the broad climate changes associated with ENSO. For example, scientists can now warn vulnerable populations of an impending El Niño event several months in advance, providing precious time in which to take steps to mitigate its worst effects. Invaluable as this prediction of El Niño is, it is just the first step toward the much longer-term goal of providing the climatic counterpart to the daily weather prediction that we have come to take for granted.

Future reports

Today we sail from Los Sueños and head north towards Puerto Vallarta. We have two new pieces of oceanographic instrumentation with us which we will discuss in future reports. The premier manufacturer of oceanographic instrumentation, Sea-Bird Electronics, in Bellevue Washington, has provided us with a thermosalinograph (TSG) which will provide a continuous record of surface temperature and salinity. The TSG is run with the SeaKeeper instrument and will provide validation and cross reference to the SeaKeeper measurements. Secondly we have a Sea-Bird conductivity-temperature-depth (CTD) instrument which we will lower from the boat to get a profile of the temperature, salinity, and pH through the surface waters. We will be able to report on our findings as we progress. As a scientist, I must say how excited I am to have these instruments in this very important El Niño event.

Michael Reynolds, Ph.D.
April 10, 2010

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Ocean Acidification: Present Conditions and Future Changes in a High-CO2 World

By Richard A. Feely, Scott C. Doney, and Sarah R. Cooley
Special Issue Feature from: Oceanography, Vol.22, No.4 (December 2009)

Abstract

The uptake of anthropogenic CO2 by the global ocean induces fundamental changes in seawater chemistry that could have dramatic impacts on biological ecosystems in the upper ocean. Estimates based on the Intergovernmental Panel on Climate Change (IPCC) business-as-usual emission scenarios suggest that atmospheric CO2 levels could approach 800 ppm near the end of the century. Corresponding biogeochemical models for the ocean indicate that surface water pH will drop from a pre-industrial value of about 8.2 to about 7.8 in the IPCC A2 scenario by the end of this century, increasing the ocean’s acidity by about 150% relative to the beginning of the industrial era. In contemporary ocean water, elevated CO2 will also cause substantial reductions in surface water carbonate ion concentrations, in terms of either absolute changes or fractional changes relative to pre-industrial levels. For most open-ocean surface waters, aragonite undersaturation occurs when carbonate ion concentrations drop below approximately 66 micromoles per kilogram. The model projections indicate that aragonite undersaturation will start to occur by about 2020 in the Arctic Ocean and 2050 in the Southern Ocean. By 2050, all of the Arctic will be undersaturated with respect to aragonite, and by 2095, all of the Southern Ocean and parts of the North Pacific will be undersaturated. For calcite, undersaturation occurs when carbonate ion concentration drops below 42 micromoles per kilogram. By 2095, most of the Arctic and some parts of the Bering and Chukchi seas will be undersaturated with respect to calcite. However, in most of the other ocean basins, the surface waters will still be saturated with respect to calcite, but at a level greatly reduced from the present.

Click on the below image to view the full text PDF:

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Ocean Acidification: A Critical Emerging Problem for the Ocean Sciences

By Scott C. Doney, William M. Balch, Victoria J. Fabry, and Richard A. Feely
Special Issue Feature from: Oceanography, Vol.22, No.4 (December 2009)

Abstract

Over a period of less than a decade, ocean acidification—the change in seawater chemistry due to rising atmospheric carbon dioxide (CO2) levels and subsequent impacts on marine life—has become one of the most critical and pressing issues facing the ocean research community and marine resource managers alike. The objective of this special issue of Oceanography is to provide an overview of the current scientific understanding of ocean acidification as well as to indicate the substantial gaps in our present knowledge. Papers in the special issue discuss the past, current, and future trends in seawater chemistry; highlight potential vulnerabilities to marine species, ecosystems, and marine resources to elevated CO2; and outline a roadmap toward future research directions. In this introductory article, we present a brief introduction on ocean acidification and some historical context for how it emerged so quickly and recently as a key research topic.

Click on the below image to view the full text PDF:

*The following article has been reprinted with generous permission from Conservation Magazine, a publication of the Society for Conservation Biology

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Garbage In, Garbage Out

When a single swath of ocean contains more plastic than plankton, the simple act of taking out the trash becomes a grueling scientific challenge

By Susan Casey
Conservation Magazine, January-March 2010 (Vol. 11 No. 1)

Fate can take strange forms, and so perhaps it does not seem unusual that Captain Charles Moore found his life’s purpose in a nightmare. Unfortunately, he was awake at the time, and 1300 kilometers north of Hawaii in the Pacific Ocean.

Returning to Southern California from Hawaii after a sailing race, Moore had altered the course of the Alguita, his 15-meter catamaran. Veering slightly north, he had the time and the curiosity to try a new route, one that would lead the vessel through the eastern corner of a 13-billion-hectare oval known as the north Pacific subtropical gyre. This was an odd stretch of ocean—“the doldrums,” sailors called it—a place most boats purposely avoided. So did the ocean’s top predators: the tuna, sharks, and other large fish that required livelier waters flush with prey. The gyre was more like a desert—a slow, deep, clockwise-swirling vortex of air and water caused by a mountain of high-pressure air that lingered above it.

The area’s reputation didn’t deter Moore. He had grown up in California with the Pacific literally in his front yard, and he possessed an impressive aquatic résumé: deckhand, able seaman, sailor, scuba diver, surfer, and finally captain. Moore had spent countless hours on the ocean, fascinated by its vast trove of secrets and terrors. He’d seen a lot of things out there, things that were glorious and grand, things that were ferocious and humbling. But he had never seen anything nearly as chilling as what lay ahead of him in the gyre.

It began with a line of plastic bags ghosting the surface, followed by an ugly tangle of junk: nets and ropes and bottles, motor-oil jugs and cracked bath toys, a mangled tarp. Tires. A traffic cone. Moore could not believe his eyes. It was as though someone had taken the pristine seascape of his youth and swapped it for a landfill.

How did all the plastic end up here? How did this trash tsunami begin? What did it mean? If the questions seemed overwhelming, Moore would soon learn that the answers were even more so and that his discovery had dire implications for human—and planetary—health. As the Alguita glided through the area that scientists now refer to as the “eastern garbage patch,” Moore realized that the trail of plastic went on for hundreds of miles. Depressed and stunned, he sailed for a week through bobbing, toxic debris trapped in a purgatory of circling currents. To his horror, he had stumbled across the twenty-first-century Leviathan. It had no head, no tail. Just an endless body.

“Everybody’s plastic, but I love plastic. I want to be plastic.” This Andy Warhol quote is emblazoned on a two-meter-long magenta-and-yellow banner that hangs—with extreme irony—in the solar-powered workshop in Moore’s Long Beach home.

Since his first encounter with the garbage patch 12 years ago, Moore has been on a mission to learn exactly what’s going on out there. Leaving behind a 25-year career running a furniture-restoration business, he has created the Algalita Marine Research Foundation to spread the word of his findings. His tireless effort has placed him on the front lines of this new, more-abstract battle. After enlisting scientists to develop methods for analyzing the gyre’s contents, Moore has sailed the Alguita back to the garbage patch several times. On each trip, the volume of plastic had grown alarmingly. The area in which it accumulates is now twice the size of Texas.

At the same time, all over the globe, there are signs that plastic pollution is doing more than blighting the scenery; it is also making its way into the food chain. Some of the most obvious victims are the dead seabirds washing ashore in startling numbers, their bodies packed with plastic: things such as bottle caps, cigarette lighters, tampon applicators, and colored scraps that, to a foraging bird, resemble baitfish. (One animal dissected by Dutch researchers contained 1,603 pieces of plastic.) And the birds aren’t alone. More than a million seabirds, 100,000 marine mammals, and countless fish die in the North Pacific each year, either from mistakenly eating this junk or from being ensnared in it and drowning.

Moore soon learned that the big, tentacled balls of trash were only the most visible signs of the problem; others were far less obvious and far more evil. Dragging a fine-meshed net known as a manta trawl, he discovered minuscule pieces of plastic, some barely visible to the eye, swirling like fish food throughout the water. He and his researchers parsed, measured, and sorted their samples and arrived at the following conclusion: by weight, this swath of sea contains six times as much plastic as it does plankton.

This statistic is grim for marine animals, of course, but even more so for humans. The more invisible and ubiquitous the pollution, the more likely it will end up inside us. And there’s growing—and disturbing—proof that we’re ingesting plastic toxins constantly and that even slight doses of these substances can severely disrupt gene activity. The fact that these toxins don’t cause violent and immediate reactions does not mean they’re benign: scientists are just beginning to research the long-term ways in which the chemicals used to make plastic interact with our own biochemistry.

In simple terms, plastic is a petroleum-based mix of monomers that become polymers, to which additional chemicals are added for suppleness, inflammability, and other qualities. When it comes to these substances, even the syllables are scary.

To take just one example, we deploy annually about 450 million kilograms of chemical compounds called “phthalates”—despite the fact that California recently listed them as chemicals known to be toxic to our reproductive systems. Used to make plastic soft and pliable, phthalates leach easily from millions of products—packaged food, cosmetics, varnishes, the coatings of timed-release pharmaceuticals—into our blood, urine, saliva, seminal fluid, breast milk, and amniotic fluid. In food containers and some plastic bottles, phthalates are now found with another compound called bisphenol A (BPA), which scientists are discovering can wreak stunning havoc in the body. We produce nearly 3 billion kilograms of BPA each year, and it shows: BPA has been found in nearly every human who has been tested in the United States.

Most alarming, these chemicals may disrupt the endocrine system—the delicately balanced set of hormones and glands that affect virtually every organ and cell—by mimicking the female hormone estrogen. In marine environments, excess estrogen has led to Twilight Zone-esque discoveries of male fish and seagulls that have sprouted female sex organs.

This news is depressing enough to make a person reach for the bottle. Glass, at least, is easily recyclable. You can take one tequila bottle, melt it down, and make another tequila bottle. With plastic, recycling is more complicated. Unfortunately, that promising-looking triangle of arrows appearing on products doesn’t always signify endless re-use; it merely identifies which type of plastic the item is made from. And of the seven different plastics in common use, only two of them—PET (labeled with #1 inside the triangle and used in soda bottles) and HDPE (labeled with #2 inside the triangle and used in milk jugs)—have much of an aftermarket. So no matter how virtuously you toss your chip bags and shampoo bottles into your blue bin, few of them will escape the landfill—only 3 to 5 percent of plastics are recycled in any way.

“There’s no legal way to recycle a milk container into another milk container without adding a new virgin layer of plastic,” Moore says. He points out that, because plastic melts at low temperatures, it retains pollutants and the tainted residue of its former contents. Turn up the heat to sear these off, and some plastics release deadly vapors. So the reclaimed stuff is mostly used to make entirely different products, things that don’t go anywhere near our mouths, such as fleece jackets and carpeting. Therefore, unlike recycling glass, metal, or paper, recycling plastic doesn’t always result in less use of virgin material.

What’s more, “Except for the small amount that’s been incinerated—and it’s a very small amount—every bit of plastic ever made still exists,” Moore says, describing how the material’s molecular structure resists biodegradation. Instead, plastic crumbles into ever-tinier fragments as it’s exposed to sunlight and the elements. And none of these untold gazillions of fragments is disappearing anytime soon: even when plastic breaks down to a single molecule, it remains too tough for biodegradation.

Ask a group of people to name an overwhelming global problem, and you’ll hear about climate change, the Middle East, or AIDS. No one, it is guaranteed, will cite the sloppy transport of nurdles as a concern. And yet nurdles, lentil-sized pellets of plastic in its rawest form, are especially effective couriers of waste chemicals called persistent organic pollutants, or POPs, which include known carcinogens such as DDT and PCBs.

The U.S. banned these poisons in the 1970s, but they remain stubbornly at large in the environment, where they latch on to plastic because of its molecular tendency to attract oils.

The word itself—nurdles—sounds cuddly and harmless, like a cartoon character or a pasta for kids, but what it refers to is most certainly not. Absorbing up to a million times the level of POP pollution in their surrounding waters, nurdles become supersaturated poison pills. They’re light enough to blow around like dust; to spill out of shipping containers; and to wash into harbors, storm drains, and creeks. In the ocean, nurdles are easily mistaken for fish eggs by creatures that would very much like to have such a snack. And once inside the body of a bigeye tuna or a king salmon, these tenacious chemicals are headed directly to your dinner table.

One study estimated that nurdles now account for 10 percent of plastic ocean debris. And once they’re scattered in the environment, they’re diabolically hard to clean up (think wayward confetti). At places as remote as Rarotonga in the Cook Islands, 3,380 kilometers northeast of New Zealand, they’re commonly found mixed with beach sand.

In 2004, Moore received a $500,000 grant from the state of California to investigate the myriad ways in which nurdles go astray during the plastic manufacturing process. On a visit to a polyvinyl chloride (PVC) pipe factory, as he walked through an area where railcars unloaded ground-up nurdles, he noticed that his pant cuffs were filled with a fine plastic dust. Turning a corner, he saw windblown drifts of nurdles piled against a fence. Talking about the experience, Moore’s voice becomes strained and his words pour out in an urgent tumble: “It’s not the big trash on the beach. It’s the fact that the whole biosphere is becoming mixed with these plastic particles. What are they doing to us? We’re breathing them, the fish are eating them, they’re in our hair, they’re in our skin.”

Though marine dumping is part of the problem, escaped nurdles and other plastic litter migrate to the gyre largely from land. If that polystyrene cup you saw floating in the creek doesn’t get picked up and specifically taken to a landfill, it will eventually be washed out to sea. Once there, it will have plenty of places to go: the North Pacific gyre is only one of five such high-pressure zones in the oceans. There are similar areas in the South Pacific, the North and South Atlantic, and the Indian Ocean. Each of these gyres has its own version of the garbage patch as plastic gathers in the currents. Together, these areas cover 40 percent of the sea. “That corresponds to a quarter of the earth’s surface,” Moore says. “So 25 percent of our planet is a toilet that never flushes.”

Our oceans are turning into plastic—are we? Wrist-slittingly depressing, yes, but there are glimmers of hope on the horizon. Green architect and designer William McDonough has become an influential voice, not only in environmental circles but also among Fortune 500 CEOs. McDonough proposes a standard known as “cradle to cradle” in which all manufactured things must be reusable, poison-free, and beneficial over the long haul. His outrage is obvious when he holds up a rubber ducky, a common child’s bath toy. The duck is made of phthalate-laden PVC, which has been linked to cancer and reproductive harm. In the United States, it’s commonly accepted that children’s teething rings, cosmetics, food wrappers, cars, and textiles will be made from toxic materials. Other countries—and many individual companies—seem to be reconsidering.

Thanks to people like Moore and McDonough, awareness of just how hard we’ve slapped the planet is skyrocketing. None of plastic’s problems can be fixed overnight, but the more we learn, the more likely that wisdom will eventually trump convenience and cheap disposability. In the meantime, let the cleanup begin: The National Oceanographic and Atmospheric Administration has investigated using satellites to identify and remove “ghost nets,” abandoned plastic fishing gear that never stops killing. (A single net recently hauled up off the Florida coast contained more than 1,000 dead fish, sharks, and one loggerhead turtle.) New biodegradable starch- and corn-based plastics have arrived, and Wal-Mart has signed on as a customer. A consumer rebellion against dumb and excessive packaging is afoot.

The gray plastic kayak floats next to Moore’s catamaran, Alguita, which is birthed in a slip across from his house. It is not a lovely kayak; in fact, it looks pretty rough. But it floats, a sturdy, two-and-a-half meter two-seater. Moore stands on the Alguita’s deck, hands on hips, staring down at it. On the sailboat next to him, his neighbor, Cass Bastain, does the same. He has just informed Moore that he came across the abandoned craft yesterday, floating just offshore. The two men shake their heads in bewilderment.

Watching the kayak bobbing disconsolately, it is hard not to wonder what will become of it. The world is full of cooler, sexier kayaks. It is also full of cheap plastic kayaks that come in more attractive colors than battleship gray. The ownerless kayak is a lummox of a boat, 25 kilograms of nurdles extruded into an object that nobody wants but which will be around for centuries longer than we will.

And as Moore stands on deck looking into the water, it is easy to imagine him doing the same thing 1200 kilomters west, in the gyre. You can see his silhouette in the silvering light, caught between ocean and sky. You can see the mercurial surface of the most majestic body of water on earth. And then, below, you can see the half-submerged madhouse of forgotten and discarded things. As Moore looks over the side of the boat, you can see the seabirds sweeping overhead, dipping and skimming the water. One of the journeying birds, sleek as a fighter plane, carries a scrap of something yellow in its beak. The bird dives low and then boomerangs over the horizon. Gone.

Susan Casey is editor in chief of O, the Oprah Magazine. The original article can be found at:
http://www.conservationmagazine.org/articles/v11n1/garbage-in-garbage-out/