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Oceanography

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This is the exciting schedule of topics whic will be discussed as Erden is at sea, hitting some of these topics head-on.....

 

Click on one of the language tabs in the upper right corner to see each week's new Education Program, in English, Chinese and Spanish - and, the first expedition in the world to ever have ongoing education, tri-lingually!   Get engaged, sit back enjoy, learn, and spread the word.  You're part of history!  Click here to see our Content Release Schedule.


Help Support Eden's adventure, to his causes, and our Ocean Recovery Alliance created education program which will follow along on his GO FUND ME SITE.  

 


 

Westbound Rower Education Week 4: Is it the Oceans or The Ocean?

 

Is it the oceans? Or is it the ocean (without the S at the end)? Those are the questions of the day, and by the end of our thinking and learning about this, we want to not only answer the question, but to understand the distinctions between them.  We will also explain why we almost exclusively use the word ocean instead of oceans here on our weekly content.

 

Above: Drop the “S” video

 

There is one ocean, and multiple ocean basins. It is one ocean because it is one giant system that has influence on our climate, contains most of the water in the world, all the life that lives in the ocean (and on land), and of course, at least for Erden, it gives us the challenge of rowing across it!  

 

How does the ocean move as one? Through ocean currents which are  driven by gravity, wind and density, via salinity and temperature. There are two types of ocean currents: 1)currents for horizontal movement, 2) upwellings and downwellings for vertical movements. Together they transport water, heat, energy, minerals, and biota, all over the world. If plastic ends up in the ocean, it follows the same fate, flowing around the world like a plastic soup, and also moving around the world, much like air pollution does in our atmosphere.

 

“Once we were fully afloat again, my quick tally identified a few items on deck had washed overboard. Nothing that significant, but I was mostly upset at allowing the sea to claim these plastic items from me. My pleas for a cleaner ocean left me feeling terrible that anything had washed over. The plastic waste problem in The Ocean is already catastrophic. I had to do better.”

Erden’s Blog (9 July, 2021)


An interesting way to visualise the ocean is to use the Spilhaus projection, one that shows the world’s ocean as a single body of water, as if the ocean is a giant lake surrounded by the coastlines of the globe. It also makes the Ocean look like look like a common blue front yard, changing the way we look at the ocean. A common is a shared resource and to maintain the shared resource, everyone must take responsibility and ownership of the shared common. If we all act in our own self-interest, a situation called the tragedy of the commons can happen where we lose the entire resource entirely. Within the ocean, an example of tragedy of the commons is overfishing, loosing a valuable source of food and all the ecosystem services the lost fish species provides.

 

 

Above: The Spilhaus projection, visualising global warm and cold ocean currents

 

This projection overlayed with a layer containing the major ocean currents, really helps visualise how the ocean moves as one. You might not be able to see from a map, but the volume of water being moved is more than enough to make it a force to be reckoned with, especially for rowers like Erden, whose Pacific crossing is at the mercy of winds and ocean currents, but at the same time he will want to use currents to his advantage on his way across the Pacific.

 

The Pacific fits perfectly into the discussion on ocean basins and where the “oceans” idea comes from. The Pacific Ocean basin is one of the many ocean basins in the world. Ocean basins being the vast landmass submerged by the ocean. Other main ocean basins include the Atlantic, Indian, Artic, and Southern, completing the “five-oceans” concept. This idea therefore favours the geography and geological make-up of the ocean basin itself. When talking about the ocean, it is often easier to discuss with others when there is some geographical context, and the ocean basins give just that. Like when we talk about “Erden rowing across the Pacific”, it is easy to grasp what he is doing and where he is doing this challenge. The surface of the ocean basin, the seabed, is perhaps the last frontier of exploration on Earth, with many parts still unexplored and only started opening up with technological advancements that can withstand the high pressures at the bottom of the ocean.

 

Above: Map of the ocean basins

 

The ocean,  ocean currents, and winds will be topics Erden will often discuss in his blog posts, and tell us that it is a very important aspect on the Westbound Row. Last week, he mentioned that he had difficulties moving west towards Hawaii because he was caught between the strong onshore (NW) winds, and the famous California current that flows south towards the Equator. These winds and currents forced him back towards the shore in the southeast (SE) direction.

 

Thankfully, he was able to find a spell of northeast (NE) winds that set the seas in his favour, putting him closer the trade wind and the Northern Equatorial current that will bring him to Hawaii then Hong Kong. The story does not end there, due to the delay, there could be an added exposure to hurricane risk when he nears “Hurricane Alley” on the way to Hawaii. These are just some of the challenges the ocean will test him with on his way across the Pacific.

 

To summarise, we only have one ocean, just one giant body of saltwater. One powerful system that can heavily influence our climate, and for some to test the human limit.

 


 

Westbound Rower Education Week 6: Ocean Currents and Ocean Gyres



If you have been following us, you will remember the numerous times we talked about ocean currents, what they do, and how they  the ocean as one single unit. This week we will take a deeper look into this subject and begin to connect the dots as to how ocean currents (deep and surface currents) influence the location of ocean gyres, how gyres move, and then allude to the idea of how collectively the ocean system also influences the Earth’s climate. 

 

In 1992, an accident happened out at sea when a container ship faced a storm, and 12 containers were lost at sea. One of these lost containers were carrying 29,000 rubber ducks, being made of rubber and without the hole to let water in like all other rubber ducks, these special 29,000 were completely waterproof and buoyant allowing them to forever float on the ocean surface with the ocean currents. Now you might think this is an environmental disaster! But there’s a good story with this because scientists saw these rubber ducks as an opportunity to model the ocean currents using the ducks as data points. How they did that was to model how the rubber duck made land fall, and account for the distance, time, and ocean conditions, they were also able to predict where potential rubber ducks might turn up.

 

Having been dropped in the Pacific on its way from Hong Kong to United States, these rubber ducks have been recovered all over the world, in Alaska, Hawaii, South America, Indonesia, Australia. Then they were found in the Artic and in the North Atlantic, reaching the Canadian and English shores after 10-15 years at sea. Their story is still unfinished, and there are rewards for those lucky enough to spot one of these ducks on land or at sea. So here's a challenge for you, look out for these rubber ducks when you are along the coast because you could be a winner!

 

Above: Map of locations where the lost rubber ducks washed ashore.

 

Like many things in the universe, the global ocean currents work like a cycle, or a conveyor belt as it is colloquially known. But perhaps this is one of the few times where the scientific name makes a bit more sense, and at the same time, describe what is going on in the ocean. This is the thermohaline circulation system. 

 

Thermohaline, is derived from “thermo,” referring to temperature; and –“haline,” referring to salinity. The thermohaline circulation, as you might guess, circulates  heat (a form of energy), and different densities of salt water with minerals and nutrients around the world, through the ocean. Temperature and salinity are therefore key driving forces to the world's ocean currents.

 

At the Earth’s North Atlantic region, sea ice is formed because of the freezing temperatures. When this happens, the salt gets left behind, and with more salt content in the water, the salinity of the water increases. Higher salinity also corresponds to higher density, which causes the water to sink. Water from the surface (less salty and dense) moves in to replace the sinking high salinity water, creating a current. The colder and salter water that is now deep within the water column moves south all the way to Antarctica, where it again sinks because of cooler temperatures. As it moves around the Antarctica eastwards, the two branches split and moves north. The branched cool water rises to the surface as it warms up, before looping back towards the southwest. The water will eventually return to the South Atlantic, then to the North Atlantic where the cycle starts again.

 

Above: Thermohaline Circulation, Blue represents the cool deep current, and Red the warmer water near the surface.

 

We cannot forget about the wind and its influence on ocean currents, more specifically, surface currents in the upper 100 metres of the ocean surface. This is because as wind blows across a surface, it creates a dragging force, sweeping or pushing an object towards the same direction as the wind. The ocean is also affected by this. So where does wind come from?

 

Wind are moving bodies of air. Like the seawater ,temperature is also involved causing warmer air to rise due to expansion (lower density), while cold air condenses and sinks. That explains the vertical movement of air, the horizontal is slightly trickier. Earth’s atmosphere has different sections of high and low pressures. Low pressure at the equator, high pressure at 30 N/S, low pressure again at 60 degrees N/S, and then high pressure at the poles. Wind always moves from a point of high pressure to low pressure, allowing air to mix from different latitudes on Earth.   Imagine Erden rowing across the Pacific, floating like a rubber duck, but with two oars, dealing with the world’s “motions” (currents and winds), to move himself from California to the Malysian Peninsula.

 

Above: Short video on Global Atmospheric Circulation

Earth’s rotation also impacts wind patterns. The rotation causes the Coriolis Effect, a pattern of deflection taken by objects not firmly connected to the ground. We cannot feel this force but can be seen in air and water. What scientists have observed about the Coriolis effect is that in the northern hemisphere, the path of affected elements deflect to the right. In the southern hemisphere, the path is deflected left. This explains the thin curved white arrows on the diagram below. 

 

For example, if you follow the entire air mass  from 30 degrees N/S moving towards the Equator, the wind is deflected right, causing trade winds that move from West to East. Westerlies are the opposite where the deflected wind moves from East to West. Based on this information, it is not a good idea for Erden to be caught in any Westerlies. However, as Erden is between the Equator and 30 degrees N, we expect him to be in the more useful trade winds as he crosses the pacific.

 

But how does all this relate to ocean gyres? Actually, all of it does! Here’s how.

 

The rotational motion of the ocean gyres is caused by wind, the Coriolis effect, and then the ocean basins themselves. We also discussed thermohaline circulation, because the gyres act like cogs or gears that help to keep this circulation going. As mentioned before, water is also affected by the Coriolis Effect, and causes a different direction of circulation in the North and Southern Hemisphere. Gyres in the Northern Hemisphere move in a clockwise direction, while gyres in the Southern Hemisphere move in a counterclockwise direction.

 

The deep ocean is also affected by this, but to a lesser extent, as we go deeper into the ocean. The outcome is what we call the Ekman Spiral.  This spiral effect describes how each layer of the ocean drags on each other because of the Coriolis Effect, just like how winds drag on the ocean surface, resulting in a spiral that goes down the water column. This transport creates a bulge in each ocean basin that is as much as one (1) metre above the mean global sea level. The force of gravity pulling on this large mass of water creates a pressure gradient similar to that in an atmospheric high-pressure system which in turn leads to a stable, rotating mass of water. This collection of water is the mechanism of how ocean plastic tends to end up in ocean gyres.

 

Above: Ekman Spiral

Ocean gyre movements are kept by boundary currents which move just on the outside boundary of the gyres. The western boundary currents are the strongest and fastest, because of the shape of the ocean basin and Earth’s rotation. These too can transport and draw plastic into the gyres, and of course, offshore winds do as well. Erden will also experience one of these strong boundary currents later in his journey, the Kuroshio Current, before going through the Luzon strait.

 

Just as water gets drawn to the calmer and stable centre of the gyre, where the bulge of ocean water is, so does the plastic that is floating or suspended in the water column. The plastic and other waste that is drawn into these gyres is what led to the “garbage patch” idea. Only it is not a literal patch of plastic, but an area where there is a higher concentration of plastic in the water. As plastic takes hundreds of years to decompose and can stay in the water for multiple human lifetimes, further breaking down into smaller pieces where it can lead to many ecological, environmental and health issues, that ultimately returns to us.

 

There is a lot of interesting science involved in investigating how plastic interacts with different elements within the marine environment, and we will discuss these topics closer to when Erden arrives in Hawaii, which could be by the end of the month (August)! Next week we will take a step back from the sciences to catch up with Erden to see how he is doing and what is happening in the ocean.

 

 


 

Westbound Rower Education Week 10: Climate System and the Ocean

 

Ocean currents circulate water, nutrients, plastic, energy and heat around the world. Today we will focus on the energy and heat the ocean carries and moves throughout the waters, and how that influences the global climate system.  The Earth’s climate system is a delicate one, and it has been a topic of study since early in human history. Still, we only have a very surface level understanding of how it all works. What we do know however, is that the sensible outcome, like temperature or precipitation, is greatly influenced by the amount of energy within the planetary boundary. So how do we define this boundary?

 

To simply describe it, the Earth’s boundary is the uppermost layer of the atmosphere, the exosphere, extending up to 10,000km above the surface of the planet. Anything beyond the exosphere, and we would find ourselves in the vastness known as “space.” Using this boundary, we can further simplify and describe the Earth’s system as a closed system.  The Earth is “closed,” because the only thing that can be transferred between the boundary is energy. Or it could be better to say the transfer of matter between the boundaries are so small that it is negligible. For example, you could argue that meteorites can sometimes pass through our atmosphere, and astronauts leaves Earth’s atmosphere into space, but in the context of Earth’s climate the transfer of energy is much more important.

 

Above: Layers of the atmosphere

 

Energy enters the Earth’s system in the form of solar energy, or solar radiation. We don’t usually refer this energy to light, because the visible range of light is only a small fraction of the energy the sun emits. The total solar irradiance is the measurement of solar energy over all electromagnetic wavelengths for an area on the Earth’s upper atmosphere when the incoming light is perpendicular.  From this the scientific community developed the solar constant, a conventional measure of 1366 Wm-2 (Watts per metres squared). It is important to note that the while the solar constant is relatively stable, the amount of energy received on the surface differs by latitude, and is a function of the Earth’s oblate spheroid shape. This shape affects the solar angle, the angle at which solar radiation comes from. In higher latitude areas (the poles), the solar angle is low, and each unit of the solar constant is spread over a larger area. You can even try a test at home with a flashlight.  First, have it shine directly onto a surface, then tilt the flashlight a little. What do you see? Remember the amount of energy (light) emitted from the flashlight is constant!

 

 

Above: how different angles affect the spread of solar radiation in different latitudes

 

In previous weeks, we mentioned that water has a much higher heat capacity than air, or than the Earth’s surface, and thus the ocean can absorb and retain a greater amount of solar energy. Much more than the land and atmosphere. The absorbed heat can be stored and then released back into the atmosphere over a long period of time. Related to this absorption of heat is the common climate change indicator: Sea Surface Temperature. This indicator is straight forward, because it is a direct way of studying the ocean taking up more energy!

 

Taking the fact that there is a difference in solar energy received based on different latitudes, we can see how sea surface temperature changes with latitude.  This can then help to explain how stored energy in the ocean is a driving force in the way ocean currents operate because energy in the ocean can be stored as heat, a driver for the world’s currents.

 

 

Above: Difference in Ocean Surface Temperature

 

Regional climate variations and the ocean’s temperature are closely related because the absorbed heat and energy from the summer is stored and the released during the winter. This interaction allows the surface and air temperatures in coastal regions to stay cooler during the summer, and warmer during the winter. Studies have shown that the surface of the land warms about 50% more than the surface of the ocean. This is due to the difference in specific heat, the amount of heat (or energy) required to increase the temperature of 1-gram of substance by 1oC, making the sensitivity of near surface temperatures over land much greater than over the ocean.

 

Since water is transparent, solar radiation penetrates the surface to quite some depth before it is fully absorbed. This zone is the photic zone and can extend up to 100m in depth. The input of solar radiation stores heat in the water during the day, then maintains radiative cooling and turbulent heat fluxes at night, resulting in small diurnal variations in ocean surface temperature.

 

The situation is quite different over land, where solar radiation is absorbed at the surface, and heat conductivity of land means that the diurnal variation in surface heating does not penetrate more than 5-10cm into the ground. Soils also have a lower specific heat, which adds to the greater temperature fluctuation on the surface, and near surface air temperatures on land during a 24-hour cycle.

 

The addition of heat gives the ocean more energy, and rising ocean temperatures will have dramatic long-term effects on the Earth’s climate. As mentioned above, the ocean is extremely efficient at trapping heat, and absorbs up to 90% of the excess heat from anthropogenic greenhouse gas emissions.  You might not notice the water getting warmer as currents keep water circulating, mixing cold with warm, but if the overall temperature rises, it has impacts on all types of wildlife, and the way weather is created. This can even impact Erden’s journey in terms of the storms, winds, waves, and weather patterns he faces going across the Pacific.

 

One of the most obvious impacts of warmer waters is that of melting of sea ice, causing major ecological damage in polar ecosystems. A heating ocean can also lead to sea level rise, not because there is more water, but because the warmer water is expanding, and taking up more space! You might already know that cold water, and ice, contracts. The melting of ice on land (not from the ocean) on the other hand, will contribute to sea level rise by increasing the volume of water in the ocean.

 

The warming ocean will affect the hydrological cycle, driving changes such as the amount of rain a region receives.This impact can be felt in two extreme ways, as some areas may receive more rain, causing flood risks, while other areas receive less, leading to droughts. The frequency and severity of extreme weather events will also change, as more area of the ocean surface can now satisfy the minimum ocean surface temperature of 27oC which is required for hurricane formation, or “typhoons” as they are called in the Asian region. Both describe the same weather phenomenon. As Erden continues towards Hong Kong, he may have to face some of these hurricanes (typhoons). We will discuss typhoons and similar storms in a later week. 

 

 

Above: The Pacific "Hurricane Alley" (2015)

 

Another climate related interaction that the ocean has, is its ability to absorb a significant amount of carbon from the atmosphere, dissolving carbon dioxide into the water. A recent study in 2020 further suggest that approximately 25% of carbon dioxide emissions from anthropogenic (human) sources each year are absorbed by the ocean. The greater concentration of carbon dioxide in the atmosphere, the more that is dissolved into surface water. From observations since the industrial era, the accumulation of carbon in the ocean has slowed the accumulation of carbon in the atmosphere, slowing the speed of warming. Meaning the ocean has been saving us from a more rapidly changing world, knowing that CO2 has a long-term impact on our climate. 

 

This absorption might sound good, and that the ocean is “saving” or protecting us, but it is not all good, because as you will see in a future section, the increase of carbon dioxide in the ocean alters the chemistry of seawater, causing a wide range of negative impacts. A warming ocean also decreases the seawater’s ability to hold carbon, which means that it will stay in the atmosphere longer, and not be absorbed into the ocean at the same rate as it has been. This decreased rate of absorption further enhances the “enhanced greenhouse effect”.

 


 Westbound Rower Education Week 17: Clouds

 

When we talk about climate change, and greenhouse gases, we immediately think of greenhouse gases like carbon dioxide or methane, and it is easy to forget about water vapour and their immense contribution to keeping the planet habitable. Water vapour is also special among the greenhouse gases because it is the only one that has stayed relatively constant throughout the past 200 years, and this is another reason why it is often overlooked. “Consistent,” in this case, meaning that the storage of water vapour in the atmosphere has not fluctuated very much compared to the changes as seen in other greenhouse gases. Due to the complex interactions clouds have with our climate, however, cloud interactions are still one of the variables we have the least certainty about when it comes to climate modelling.

 

Water vapour is the gaseous form of water, with the solid and liquid forms being ice and water respectively. For water to change its state (e.g to ice or vapour), there needs to be an energy or heat exchange. For liquid water to turn into water vapour, energy (heat) needs to be added, and the liquid is Evaporated into water vapour. The reverse process is condensation, where energy is released. These exchanges of heat are the baseline of how clouds are formed.

 

Before we talk about clouds however, are Steam and Water Vapour the same thing? They are both gaseous forms of water right? This is correct on a technicality, since water vapour is a term describing the gaseous from of H2O. The subtle difference between the two is how the gaseous state is formed. In steam, water vapour is produced when the water reaches its boiling point, or 100C or above. Steam is also visible to our eyes. The other type of water vapour is created from evaporation, which is related to the volatility of water, can occur at any temperature and invisible to our eyes. Solid ice can also change into water vapour, through the process of sublimation, the conversion between the solid and the gaseous phase without the intermediate liquid stage. Other chemicals can evaporate and form vapour as well and check out this  this timelapse of water, acetone, and ethanol (the latter two are more volatile than water) to see how volatility affects evaporation!

 


Timelapse of Water, Acetone and Ethanol evaporation

 

In short: All Steam is Water Vapour, but not all Water Vapour is Steam

 

Clouds form when the air reaches a saturation point, a threshold describing when the air contains as much water vapour as it can hold. The saturation point can be reached in two ways. The first is the accumulation of water vapour until it reaches the maximum volume of water the air can hold. The second is temperature dependent, where the saturation point is reached by reducing the temperature of the moisture filled air, which in turns reduces the amount of moisture the air pocket can contain. When the saturation point is reached, the water vapour becomes visible water droplets in the form of clouds, and fog when it’s near the surface.

 

The atmosphere is filled with tiny airborne particles of dust, soot, microorganisms, and many others small particles. They come from various sources, both natural and anthropogenic. Ash from volcanoes, smoke from forest fires, salt from sea spray, grains of sand and dust taken up by wind are all examples of natural aerosols. Anthropogenic sources can include smoke and particles from burning fossil fuels. Plastic fibres have also been observed as aerosols, and scientists are just finding that a lot of this comes from car tires when they wear down from bad roads and daily friction on asphalt. The size range of aerosol particles can vary from nanometres to millimetres and can be both solid particles and liquid droplets. 

 

 

Above: “Shiptracks”, clouds in distinct line formations following aerosols released from ships

 

Aerosols can have multiple functions in the atmosphere which include the reflection of light , the scattering of solar radiation, and the forming surfaces where water vapour can condensate into water droplets, aiding the cloud formation process. Clouds with greater aerosol content often have more small droplets than in pristine clouds. Smaller water droplets means that a larger surface area is available for reflecting light, making aerosol dense clouds appear brighter than clouds with larger droplets.

 

Clouds occur in three basic shapes, cumulus (puffy), stratus (layered) and cirrus (wispy). Other than shape, altitude is another way to identify clouds. Clouds below 2km are considered low, clouds from 2-6km are mid-level, and clouds above 6km are high. And finally for descriptions are the prefixes “nimbo-“ and postfix “-nimbus” differentiating between clouds from which precipitation is falling. 

 

Above: Different types of clouds (shape, altitude, precipitation)

 

One of the reasons why cloud interactions are so difficult to predict when it comes to climate modelling is because different types of clouds play a different role in regulating climate. The cirrus clouds at high altitudes tend to trap infrared radiation from the Earth, much like the other greenhouse gases. On the other hand, lower altitude clouds tend to shade the surface, and reflect solar radiation back into space. So in a way, clouds have a potential to both heat and cool the surface. On top of this, increases in surface temperature are also likely to affect the hydrological cycle, changing the fluxes of water movement between the surface and the atmosphere. Current models suggest an intensification of the hydrological cycle, where water moves faster through the cycle, changing regional precipitation regimes. However, it is still unknown whether this intensification will affect total cloud cover in the future.

 

The cloud layer is also exceptionally large, and at any given time it is estimated that approximately  60% of the planet surface is covered by clouds. This is not a bad thing for Erden, as it is much nicer rowing in the shade than in direct sunlight all the time. Erden is now nearly 700 miles into the second leg of the Westbound Row, making more progress than expected because the winds are in his favour. He writes in his blog that on some days he has clocked 60 mile days (his average is 30-35 miles per day). With the winds in Erden’s favour, it is fitting that we discuss what and how winds are created next week. We will also be hearing more from Erden in the next few days as we plan to host another live classroom session with Exploring by the Seat of Your Pants. 

 

Above: Erden on his rowing seat


 

Westbound Rower Education Week 18: Wind

 

We cannot understate how important the wind is in attempting challenges like doing the Westbound Row. We should say that all ocean crossings rely on wind because the wind’s direction, strength and speed all impact ocean crossing journeys. Erden is attempting a huge human-powered ocean crossing, across the entire Pacific Ocean, as you know, but just because he cannot set up a sail to harness the wind like other boats, the wind does push him along, and that is an important feature of his course and expedition planning. But not all wind is good! Erden learned this first-hand that strong onshore winds pushed him much further South than expected, in fact, almost to Mexico! This added nearly two weeks to his anticipated arrival in Hawaii. Then right before his arrival in Hawaii, he had to manoeuvre around a hurricane! It seems like it is only recently that the winds are in his favour, and the difference between having the wind with, or against you can be huge.

 

Wind is essentially a horizontally moving pocket of air, and like the ocean, it also carries and circulates energy, heat, and any other airborne particles that are in the atmosphere. The way  different pockets of air move in the atmosphere also have similarities with the ocean, because the movement of the wind is also  related to temperature. At the Equator, the sun warms the surface (land and ocean) more than it does at the poles. This uneven distribution of heat and energy causes the warm air at the equator to rise, and move towards the two poles, forming a low-pressure system. As the warm air does this, the cooler, denser air moves over the Earth’s surface towards the equator, replacing the poleward moving warm air. This creates a high-pressure system. The difference in atmospheric pressure generates winds, blowing from a point of high pressure to a point of low pressure. These winds can range from a light breeze, to being a hazard like the hurricane Erden faced in August.

 

On land, wind is an important variable to weather forecasting and climate modelling. When wind transports moisture and heat in the atmosphere, different weather conditions can occur when the wind shifts direction, or when fronts of warm and cool regions of air meet. When the right conditions occur, heavy rainstorms, thunderstorms and other atmospheric turbulence can form. Information on wind and its direction is always readily available in your local weather forecast and online. We highly recommend anyone who uses the ocean for sports, recreation, travel to always be aware of the wind predictions, as winds and waves can be a hazard.

 

 

Above: Animation of the Four types of fronts (Space Stuff)

 

Another interesting outcome of wind movements is a waterspout, which Erden may encounter at some point, as they are the most common over subtropical and tropical parts of the ocean, which is within the range of the Westbound Row.  The first type of waterspout is “non-tornadic,” meaning that it is not harmful except within the small spot of intense wind.  This causes wind to pick up the water, spraying it  around the spot, which is occasionally accompanied by a condensation cloud rotating and extending from the base of the cloud, or funnel, which is formed, which may or may not reach the surface of the water. The second type of waterspout is tornadic, which can be harmful to boats because it is essentially a tornado over water and can actually suck up water from the surface. They are formed exactly the same way as tornadoes on land and are rare occurrences.

 

Above: Do You Know How Waterspouts form? (The Weather Channel)

 

Wind energy is a very useful form of energy, and has been harnessed by humans for a long time, like windmills being used for grinding grain, pumping water, and electricity in the more modern wind turbines. Ocean crossings and sailing are other uses  of wind energy with long history for almost as long as humans have been on the planet. Erden also harness wind energy by making use of winds that are pushing him in the right direction. Finding wind (or avoiding it), and being in the right place, with the ability to anticipate where the “useful wind” will work in his favour, is an important part of his navigation. This allows him to get to his next target location, while also being able to carry out more citizen science work as he moves about on the ocean surface.

 

One of Erden’s recent citizen science projects was to make a rendezvous with the Sentinel-1 SAR satellite. A Synthetic Aperture Radar (SAR) satellite sends harmless microwave beams towards the Earth’s surface and forms an image of the surface by capturing the microwave “backscatter” (images created from the reflection of the microwaves on the sea surface). There are many commercial and scientific applications to SAR satellite data, with research and development constantly working to improve on the quality and resolution of the data.

 

Above: Sentinel 1 SAR video (ESA)

 

Erden’s contribution was to ground-truth the Sentinel-1 SAR satellite data by being within the 20km x 20km satellite image, and to describe and capture images of the actual ocean conditions around his rowboat so the two can be compared by researchers at the University of Hawaii. For Erden to gets to this target, which is comparable to “needle-head-sized” target in the middle of the ocean was the first challenge. The second challenge was to get to the point at the right time. Using the wind and current data and analysis by Jason Christensen, a friend and experienced route planner for ocean racing and other vessels, and some simple maths from Erden in the rowboat, Erden was able to be 1.7km from the image centre, close to a bullseye given the circumstances with the wind and current. This marks another one of the collaborations Erden have with scientists and their research, further justifying the Explorers Club Flag Expedition status for the Westbound Row. Erden is now around 800 nautical miles (1482km) west of Hawaii, and around 2400 nautical miles (4445km) to get to Northern Marianas, which he plans to reach in early January 2022. 

 


 

Westbound Rower Education Week 19: Navigating the Ocean Currents 

Last week we talked about how the wind can aid Erden’s Westbound Row by pushing him across the Pacific. The wind also enables him to spend some of his time contributing to the sciences by being a citizen scientist collecting data for scientists researching topics such as remote sensing, winds, ocean current modelling, and conservation biology. However, we did not mention another abiotic factor that influences Erden’s row - the ocean currents.

 

While winds push his rowboat above the water, the force of ocean currents occur below the waterline. Currents carry the rowboat from beneath in the direction that the water is flowing. of the moving water. Just like the wind, ocean currents can make or break Erden’s ocean crossing, and without Erden’s human power input, the fate of the rowboat will be the same as ocean plastics, ending up trapped within the ocean gyres or drifting endless around the world in the ocean.

 

The Westbound Row is a historical first, rowing from East to West from North America to Asia, achieving the first ever mainland-to-mainland row above the Equator. The most common route used in Pacific Ocean crossings is the East-West route, such as North America and Peru or Chile, to Papua New Guinea and North Australia. Erden also did a similar Pacific Ocean crossing back in 2007 (California, US – Papua New Guinea), during his first human powered circumnavigation of the planet. Which was also the the first half of his Around-N-Over project. However, since all previous Pacific crossings by ocean rowing either starts or end in the Southern Hemisphere, Erden will be writing another page in the history books when he arrives in Hong Kong early next year.

 

But why has nobody attempted this challenge of crossing the Pacific north of the Equator in the past? One of the reasons is that only a handful of rowers and adventures have dared to cross the Pacific by rowing due to the time needed, and the lack of land and islands along the way case of any emergencies, and due to the ocean currents. As mentioned in Erden’s blog posts, our education content here, and on the live classroom sessions with Exploring by the Seat of Your Pants, Erden’s row takes place generally at the periphery of the North Pacific Ocean gyre system and encounter’s three major ocean currents of the Pacific. The first is the California Current, the second is the North Equatorial Current where Erden is now, and the third is the Kuroshio Current. Using these faster moving waters at the periphery of the gyre system can propel Erden across the ocean faster and therefore reducing the number of hours Erden needs to spend at the rowing seat as a bonus. If Erden had chosen to cut straight through the centre of the gyre instead, the Pacific crossing would be likely to last much longer given the still water at the centre of the gyre. He would also have to fight currents that move in the wrong direction (North and East) after he passes the centre of the gyre. This would not be an ideal scenario.

 

Above: North Pacific Subtropical Convergence Zone and North Pacific Ocean currents

 

The first of the prevailing current Erden encountered in the Westbound Row is the California current, which is a clockwise-moving cold-water current that moves southwards along the western coast of North America between latitudes  48° N and 23° N. At the same time, offshore breezes push ocean surface water away from the coast. As a result, cooler, nutrient-rich water rises to take its place – a process called upwelling. The combination of cool water and abundant nutrients from upwelling promotes growth and productivity of primary producers. Primary producers form the lowest trophic level or the base of the aquatic food web. They synthesize their own energy, with many using the sun's energy to build carbohydrates. The nutrients brought up from upwelling subsequently become the centre of  critically important food webs that includes highly productive fisheries, marine mammals, and sea birds. The surface velocity of the California Current is commonly less than 0.9km per hour. When Erden was using the California Current in June-July 2021, he also faced strong NNW winds that forced his course southwards and causing delays to his arrival in Hawaii.

 

 

Above: Infrared Remote Sensing imagery of the California current

 

North Equatorial Current (NCE) is the westward wind-driven current that is mostly located near the equator. There is a similar and equivalent north equatorial current in the Atlantic Ocean Basin, but for the rest of the section when we use NCE we are referring to the one in the Pacific. The NCE is generally found within the latitude band 5°N - 20°N (with some seasonal changes). Being a wind driven current, the westward motion by the NCE is driven by the belt of northeast trade winds. Because the movement is initiated above the surface, the depth of the NCE only extends down to about 400m. If you check out Erden’s tracker you can notice how straight he is going because of the combination of the NCE and northeast trade winds

 

At the most western end of the Northern Equatorial Current, the equatorial current splits into two separate currents near the East coast of Luzon, Philippines. The first is the Mindanao current, which flows southward. The second, and the more significant one, is the Kuroshio Current that flows northwards and acts as the west boundary current in the North Pacific. The Kuroshio Current is a fast one, at times reaching up to speeds of 2-metres per second (7.2km per hour). The Kuroshio Current plays a vital role in the circulation of the North Pacific Ocean, transporting large amounts of heat and affecting the climate on the adjacent land masses. For example, the water temperature offshore strongly influences cloud formation, cloud cover and rainfall. 

 

The biggest challenge for Erden when facing currents will likely be when he needs to cross the Kuroshio Current and maintain the westward course towards the Luzon Strait while battling the fast northward moving current. It is one of the moments that will test Erden and all the training he has done since his original launch from California back in June 2021. Luckily, he still has a few months before he reaches this part of the Westbound Row. This is where the knowledge and research from Erden’s support team will become critically important. Some of Erden’s team guiding him through the Pacific are some of the top current-flow scientists in the world, like Nikolai Maximenko and Jan Hafner from the University of Hawaii.

 

Above: The Kuroshio Current

The wind and current are not only a physical force of nature, but also play a vital role in the ocean biochemistry and the biotic structure of ocean ecosystems. The complexity of modelling such forces and applying to ocean crossings requires constant collaboration between Erden, ocean current modellers and scientists, and experts in ocean navigation. In the next few weeks, we will invite several special guests and experts in these fields to join us, Erden and classrooms through the live classroom sessions with Exploring by the Seat of Your Pants. We will be discussing the complexities of multidisciplinary research and applied sciences, in order to connect the dots between the sciences and ocean rowing. We will be sending out information about these on the Westbound Rower Facebook page, so keep an eye open for these and secure yourself or your classroom a spot on these events. In the meantime, follow Erden’s Instagram, and Erden’s blog, he regularly posts images and interesting encounters he has while he is at sea!

 


 

 

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