Why locating MH370 in the Southern Ocean is so difficult

There's nothing easy about this.

Reuters/Jason Reed

From The Conversation by Erik Van Sebille

Searching for the debris of flight MH370 in the Southern Ocean is not just a case of looking for a needle in a haystack; it is a case of searching for a needle that moves hundreds of kilometres every day in one of the most hostile and constantly changing areas in the world.
To make matters worse, it is also one of the most remote locations on Earth.

 Southern Ocean ocean map (AHS) in the Marine GeoGarage

I should know, I’ve seen this myself.
In December 2013, I was on an expedition south of New Zealand to look at how dynamic the currents in this part of the world were.
We deployed ten pairs of satellite-tracked drifting buoys into the ocean, at exactly the same moment and with only 10m spacing.
Within days, the buoys within each pair were already at least kilometres apart.
Three months later and some of the pairs are now separated by thousands of kilometres.

Planned search area 24 March (AMSA)

The missing flight

If Malaysia Airlines flight MH370 did go down off the coast of Western Australia, given the distance from land and the nature of the ocean in this part of the world, it could hardly have gone down in a worse part of the ocean.

The Australian Maritime Safety Authority last week released images showing two objects – one 24m, the other 5m in size – which led to a massive air and sea search of the area.

A photo released on March 20 by the Australian Maritime Safety Authority shows satellite imagery of objects that may be debris of the missing Malaysia Airlines Flight MH370.

Coords : 43°58'34"S / 90°57'37"E

The region, just over 2,000km southwest of Perth, is extremely hostile.
Winds and waves are among the strongest and highest in the world so any expedition to locate and possibly retrieve any wreckage and the plane’s black box will be difficult.

 China’s SASTIND has detected suspected a floating object

22m-long and 13m-wide in southern Indian Ocean

 Search: Suspected objects in the southern Indian Ocean viewed from a Chinese IL-76 plane

Before the recovery of the plane can begin, assuming the debris are conformed to be those of MH370, the search team will have to estimate where the plane actually hit the water.
That is not going to be an easy task.

An ocean in motion

The Southern Ocean is extremely volatile, with currents changing speed and direction from day to day, making it particularly hard to back track the drift of debris to the original impact point.

One of the unique features of the Southern Ocean is that it is the only place in the world where water can keep on moving eastward without ever hitting land.
Because of this, and the strong winds, the water is swept along at very high speeds, sometimes almost 2m a second.
This is much faster than any other place in the world.

At those high speeds, the current becomes unstable.
It starts breaking up and forms eddies.
These eddies are similar to the vortices you may see behind wakes in a river or the spiralling and treacherous winds that can form behind tall buildings in the inner city on a windy day.

This animation shows the rich dynamics of eddies and jets in the Indian Ocean sector of the Southern Ocean, which act to mix ocean waters.

It shows a high resolution (1/20°) regional simulation of the Southern Ocean, including a peek at a submesoscale (1/80°) resolving nested simulation.

The difference in the Southern Ocean is that these eddies are much larger - almost 50 km in diameter - and they are not stationary but constantly move around.
The ocean here is chock-full of these eddies, which can also extend down for more than a kilometre.
The underlying physics of ocean eddies is similar to that of cyclones and hurricanes in the atmosphere, but the velocities are much lower.
The eddies are roughly circular areas of high or low pressure, and because of the rotation of the earth, water starts swirling around them.
The stirring of the ocean eddies in the Southern Ocean make the flow of debris highly unpredictable.
This is the oceanic equivalent of the butterfly effect, where a small change in initial position can very rapidly lead to changes in trajectory.

Drifting away

Because of the stirring by the eddies, the sheer size of the search area doesn’t come as a surprise.
It was recently announced that a Chinese satellite has spotted possible plane debris 120km southwest from where an Australian satellite spotted it two days earlier, and that a French satellite has spotted debris 800km to the north.

 The map shows the movement of all the buoys ever deployed in this region of the ocean.

The star marks the location of the objects identified on Australian satellite images. 

Erik van Sebille

The pieces of floating debris from the plane will all have taken a different route through the sea of eddies. In fact, the debris that are still at the surface could occupy an area easily hundreds of square kilometers wide by now.
If the search teams don’t find the debris soon, the remains of MH370 could even be in completely different oceans, as this simulation shows.

 How far any debris could drift in one year from potential crash site (marked by yellow duck). adrift.org.au, CC BY-NC-ND

This simulation was made up of the data trajectories of the thousands of drifting buoys deployed in the ocean over the last three decades.
As you can see, some of the debris will move to the Indian Ocean off Perth while some of it will end up in the South Pacific Ocean.

 Mike Barton, rescue coordination chief, left, looks over the maps of the Indian Ocean with Alan Lloyd, manager of search and rescue operations at AMSAR.

Photo / AP

The ocean clock is ticking and if we don’t find something soon, it becomes increasingly difficult to find the aircraft.

Links :

• MotherJones : One reason it may be harder to find flight 370: We messed up the currents 
• Mashable : Malaysia Airlines search area is the worst place on Earth to lose a plane 
• EarthNullschool : animated map of currents
• The Australian / The Telegraph : How satellite pings located missing Malaysian flight MH370 
• PhysicsCentral : How Inmarsat hacked their data to find flight MH370

Voyager: How long until ocean temperature goes up a few more degrees?

The NOAA polar-orbiting satellites (POES) have been collecting sea surface temperature data for over 22 years. This animation is a compilation of that data from January 1985 - January 2007.
Of note are the changes in the Gulf Stream, El Nino and La Nina cycles in the Pacific, and the seansonal changes in sea ice cover.

From Scripps

The average temperature of the sea surface is about 20° C (68° F), but it ranges from more than 30° C (86° F) in warm tropical regions to less than 0°C at high latitudes.
In most of the ocean, the water becomes colder with increasing depth.
At 2000 meters, (6,560 feet) the global average temperature is about 2.5°C (36.5° F), and at some locations the ocean bottom temperature is less than 1°C (33.8° F).

The long-term warming of the oceans is strongest at the sea surface, temperature (SST) has increased by about 1°C over the past since 1910, or 0.1°C per decade.
SST has been measured all over the world for more than a hundred years by ocean-going ships.
Below the sea surface, historical measurements of temperature are far sparser, and the warming is more gradual, about 0.01°C per decade at 1,000 meters.

The long-term increase of SST and the warming over the whole water column are both important in the physics of climate.
Sea surface temperature is an important factor because it controls the exchange of heat between the ocean and the atmosphere and in so doing, influences the temperatures experienced on land.
Heat content averaged over the full water column is important because over 90 percent of the net energy being absorbed by the earth’s entire climate system – in the air, ocean and on land and ice – is stored in the oceans.
The oceans have much greater capacity to store heat than the atmosphere, and ocean currents and mixing carry heat away from the sea surface into the deep ocean.
Over the past 50 years, heat energy has been stored in the oceans at a rate of about ½ watt per square meter of surface area.
This is equivalent to having each 10 meter-by-20 meter area on Earth continuously warmed by a 100-watt light bulb.

On time-scales of a decade or two, global SST fluctuates by about 0.2° C from year to year due to naturally-occurring climate phenomena such as El Niño and La Niña so the long-term warming trend is not evident in 10-year periods.
That is the case in the most recent decade.
Nevertheless, the warming over the whole water column occurs at a steadier rate than for SST, and indeed the heat content of the oceans has continued to rise in the past decade at the long-term rate of about ½ watt per square meter.

So it would take a few hundred years for SST to increase by a few more degrees Celsius if it continues at the same rate as the past century.
Climate models predict that the rate of warming will increase.
However, even the moderate warming that has occurred so far is having profound impacts on marine life, sea level, and on Earth’s water cycle.
Sea level is rising by 2-3 centimeters per decade globally due to melting of glaciers and ice sheets and to thermal expansion of the seawater.
Evaporation and rainfall have increased on a global basis as the warming ocean puts more water vapor into the atmosphere and more energy into global weather systems.
Marine species are being displaced toward higher latitudes by the warming ocean, disrupting ecosystems.
So while the rate of ocean temperature increase seems small, its effects on marine life, sea level, and the earth’s water cycle are the primary concerns for society.

Passion for the sea

Knut Frostad is a Norwegian sailor, a former Olympian, Volvo Ocean Race skipper and motivational speaker.

He now runs the world's premier round the world sailing race.
Here Knut talks about his fascination with the sea, with danger, and with the Volvo Ocean Race.
"Everyone has a responsibility to identify what really triggers you in life"

From VolvoOceanRace by Austin Wong

“This race is so much more than a sailing event” according to Volvo Ocean Race CEO Knut Frostad.
But what does that mean to a non-sailor like me?
I came to the race with no experience of sailing and yet it has completely sucked me into a world of adventure, personalities, and at-the-limits action.
I wondered what the hell happened to me - so I asked Knut.

I have an embarrassing confession.
I’ve worked for the Volvo Ocean Race for almost two years, and yet I don’t sail.
Can’t sail.
I get seasick and the only knot I can tie is the one that fastens my shoelaces.
Despite this I have fallen in love with this event.

The man sitting opposite me knows a thing or two about sailing.
Knut Frostad is the CEO of the Volvo Ocean Race, a former Olympian, and a two-time skipper in this race; a man with a rich history. In short he’s the kind of guy I always want to know more about.

I made this video with Knut attempting to get inside his passion for the sea and sailing.
His interview is thoughtful, insightful, and going back to that word again – passionate.
Perhaps he can help me to understand the reasons I’ve become so invested in this event.
What is the mysterious appeal of the Volvo Ocean Race?

“We have a very real event where people risk their lives, it’s very serious. And we bind countries together. We don’t solve world problems, but we are creating something that people care about beyond money, and status and a lot of other things.
“In some extreme sports today you can do it just to get exposure. But this race is way too long and way too hard, and way too risky to do it for exposure. After 10 days at sea you don’t even know if people are watching you. And that’s what’s special about this race, that people do it for real. They do it because they mean it.”
And though the race is a top sporting competition and a massive commercial operation, the fuel that really drives the Volvo Ocean Race is passion.
That was what hooked me.
Passion is authentic, and to me, passion is one of Knut’s defining qualities.
I ask if he feels that being the driving passion behind this race can be a burden.
“First of all I think it’s not just me - people have passion throughout the race, but it can be for different pieces of the puzzle, and to me it’s much more about defining the real things that matter, whether that’s sailing or not. What I’m trying to do with this race is to translate it in a way so that people feel that it matters.
“Sometimes maybe I carry the sailing side and the responsibility for making people enthusiastic about it, but at the same time I’ve seen so many people being enthusiastic about this event and not taking it from the sailing angle. They never became fans of sailing as such, but they became huge fans of this race and what it does to people. And for me that is what this race is about. This race is a sailing event, but it’s so much more. It’s about a group of people sharing passion, travelling around the world doing cool stuff.”
And indeed the Volvo is full of ‘cool stuff’, but it’s also a monumental task to put together.
To Knut, this is a key aspect of its appeal.
“The reason I like this event is because I know it’s so rewarding. All the cities, all the millions of people, all kinds of crises all the way. The race is very difficult, and very hard, and that’s why you do it.
“The Mount Everest we’re trying to climb is that we start from zero every race and then we try to get the world’s attention, and keep all the sponsors happy, 56 stakeholders and 11 cities. To me it’s more challenging than even sailing it.”
I feel I’m closer now to understanding the essence why I love this event.
The race is an authentic challenge for both body and spirit.
I’m curious about one more thing - Knut is a man who exudes easygoing confidence, but surely he must have his down days?
“It changes, every day for me as anyone else.” he laughs.
“But everyone has a responsibility to identify what really triggers you in life.
“There are so many jobs that are easy, and they’re so unrewarding. Something that’s very special to this event is that when you’ve done a race, you can look back and know you played a big role in it. And I think every person in this race really does. You can see yourself in the event.”

Dakuwaqa's Garden - Underwater footage from Fiji & Tonga

Underwater footage shot whilst scuba diving in the Fiji islands and Tonga.

Featuring colorful coral reefs, huge schools of tropical fish, sharks, humpback whales, underwater caves, scuba divers and much more marine life from the south Pacific.

Seeing equinoxes and solstices from space

The four changes of the seasons, related to the position of sunlight on the planet, are captured in this view from Earth orbit.

From NASA

One of the most frequently misunderstood concepts in science is the reason for Earth’s seasons.
As we experience the September equinox today—anyone try to balance an egg yet?—we thought we’d offer a space-based view of what’s going on.
Around 6 a.m. local time each day, the Sun, Earth, and any geosynchronous satellite form a right angle, affording a nadir (straight down) view of the terminator, the edge between the shadows of nightfall and the sunlight of dusk and dawn.
The shape of this line between night and day varies with the seasons, which means different lengths of days and differing amounts of warming sunshine.
(The line is actually a curve because the Earth is round, but satellite images only show it in two-dimensions.)
The Spinning Enhanced Visible and Infrared Imager (SEVIRI) on EUMETSAT's Meteosat-9 captured these four views of Earth from geosynchronous orbit.

 acquired December 21, 2010 - September 20, 2011

acquired December 21, 2010 download large winter solstice image (1 MB, JPEG, 3712x3712)

acquired March 20, 2011 download large spring equinox image (1 MB, JPEG, 3712x3712)

acquired June 21, 2011 download large summer solstice image (1 MB, JPEG, 3712x3712)

acquired September 20, 2011 download large fall equinox image (1 MB, JPEG, 3712x3712)

acquired September 19, 2010 - September 19, 2011 download high definition animation (23 MB, QuickTime)

The images show how sunlight fell on the Earth on December 21, 2010 (upper left), and March 20 (upper right), June 21 (lower left), and September 20, 2011 (lower right).
Each image was taken at 6:12 a.m. local time.
On March 20 and September 20, the terminator is a straight north-south line, and the Sun is said to sit directly above the equator.
On December 21, the Sun resides directly over the Tropic of Capricorn when viewed from the ground, and sunlight spreads over more of the Southern Hemisphere.
On June 21, the Sun sits above the Tropic of Cancer, spreading more sunlight in the north and turning the tables on the south.

The bulge of our spherical Earth blocks sunlight from the far hemisphere at the solstices; that same curvature allows the Sun’s rays to spread over more area near the top and bottom of the globe.
Of course, it is not the Sun that is moving north or south through the seasons, but a change in the orientation and angles between the Earth and its nearest star.
The axis of the Earth is tilted 23.5 degrees relative to the Sun and the ecliptic plane.
The axis is tilted away from the Sun at the December solstice and toward the Sun at the June solstice, spreading more and less light on each hemisphere.
At the equinoxes, the tilt is at a right angle to the Sun and the light is spread evenly.
The equinox and changing of the seasons occurs on September 23, 2011 at 9:05 a.m. Universal Time. (Our September image above is a few days early.)
Equinox means "equal night" in Latin, capturing the idea that daytime and nighttime are equal lengths everywhere on the planet.
That is true of the Sun's presence above the horizon, though it does not account for twilight, when the Sun's rays extend from beyond the horizon to illuminate our gas-filled atmosphere.

Read more about the March Equinox from Date and Time

Related Reading

1. Stern, D. (2005) From Stargazers to Starships: Seasons of the Year. Accessed September 22, 2011.
2. U.S. Naval Observatory Day and Night Across the Earth. Accessed September 22, 2011.
3. U.S. Naval Oceanographer Earth's Seasons. Accessed September 22, 2011.