12
AUG
2015

MH370 debris and yellow rubber ducks – Mohd Fadzil Akhir

A day before the prime minister made an announcement confirming that the debris found on Reunion Island was from MH370, Berita Harian published an article entitled “Pakar yakin serpihan ditemui adalah MH370”.

Instead of showing any interest, Facebook users started to post unhappy comments, claiming that it was just a way to divert attention from the many issues that the nation is facing.

The so-called “pakar” in the article happened to be me, and some comments even said that I was paid by the government to made such claims. I don’t really take it seriously. If not for my friend who shared the Facebook comments, I probably wouldn’t even know about it.

But the big question is still there, and it needs proper clarification and explanation. The main question people are asking is, how does the flaperon travel 5,000km to that particular island, which we had never heard of before? And why did it appear now?

I spent nearly 45 minutes running an unintended oceanography crash course for the journalist just to explain how we know that such debris is able to travel that far and reach the other end of Indian Ocean, using what we called “drifters modelling”.

So this article will try to explain as simply as possible how oceanographic science might be able to tell you the truth about how the debris travelled and why I am so confident that the debris is in fact from MH370.

For that purpose, I will use rubber ducks as an example. Why rubber ducks? In almost all oceanography introductory books, yellow rubber ducks are used as an example when explaining how currents or waves move and bring along any floating particles. I guess it will be easier to imagine.

First of all, we were basically confident of the search area of MH370 and we suspected there must be some debris, but nothing was found. Because of time delays at earlier stages of searching, the debris must have move further. So how can we trace it?

To make sure we can estimate where the debris is moving, it would be great if we could put a floating device like a drifter. A possible thing to do is, let’s say, put 500 rubber ducks in the search area and track their movements. So we can estimate where the debris is heading, the distribution and how it spreads through time.

Sounds like a good idea? Yes, but it is not realistic. The ocean is too big, and there is no way we can track the rubber ducks unless you equipped them with GPS trackers which will cost you a fortune to fit on 500 rubber ducks and whose batteries can last only a few months. After all, releasing a rubber duck sounds so childish and unreal when dealing with this high profile plane missing case.

But we have an alternative. You may be surprised that oceanographers actually did just that. But it is totally in a very different form. To make ocean currents predictions, oceanographers nowadays used numerical modelling to simulate the movement of the current system. This will tell you where the current moves in the past and future.

However, it is hard to visualise the movement of debris just by looking at the simulation. Thus, drifters are virtually applied on the ocean current models at the suspected crash area. This is a system that known as “drifters modelling”. These drifters act similar to the rubber ducks – the only difference is, they are virtual drifters. And of course, the shapes you see on the computer are not ducks, but they float just like them.

This system is made to predict. It can basically show you where the drifters go in one week or even in 2 years’ time. With a mix of general understanding of Indian Ocean currents and the modelling results, we can predict where the current moves and which possible area in which it could possibly wash up.

Why is such a prediction important? It is just another way to confirm any debris found at sea could be from MH370. A few months after the crash, somebody found something near the north coast of Western Australia. Nine months later, someone suggested something might have washed up at beach near Java. And this month you get something at Reunion. The model prediction ruled out the first two and confirms the latter.

There were a few drifters models built for this purpose by agencies from different countries. They mostly produced results similar to those produced by my collaborators in University of Western Australia. Our analysis of these results showed the current from the search area would move north and then turn west towards the Madagascar area, which includes Reunion and Mauritius.

This movement would stay at 10oS latitude without reaching the equator because there is another opposing current near equator. So, for any debris to reach Maldives is very unlikely (referring to recent news on debris in Maldives).

The verdict: estimation shows that it is possible for debris to arrive in Reunion and it could have arrived there between 12 and 18 months’ time. Not only the location, but also the timeframe of the finding of flaperon on the island fits nicely with the model prediction. It is almost impossible that this happened by chance.

The final question remains unanswered. With what we have now, can we find the plane? Will this virtual duck drifters model make searching easier?

I’m afraid not. What happened over the past week only confireds one thing: that the debris is from MH370. And the most useful thing the drifters model tells us is, there is a high possibility that the search area is the right place.

Nonetheless, the place to which we are referring is not a spot, but an area. The size of this area is vague and in ocean scales, it is very large although it looks pretty small on the map. We are dealing with an area nearly similar to the size of our country Malaysia.

We might not know much, but we can be certain of a few things by now. At least on a positive note, this searching has turned from mission impossible to mission difficult. The yellow rubber ducks at least have given us some light. – August 12, 2015.

* Dr Mohd Fadzil Akhir is an oceanographer at Institute of Oceanography and Environment (INOS), Universiti Malaysia Terengganu.

* This is the personal opinion of the writer or publication and does not necessarily represent the views of The Malaysian Insider.