slats11
A human body in the water will drift with the water current much more so than it will be "blown" through the water by wind. Bodies are mostly water, have a density just a little greater than or just a little less than water (hence some sink and some float), and there is little above the water to catch the wind. So the drift of bodies predominantly reflects the effects of water currents.
Fat people have greater buoyancy than thin people, i.e. the density of fat is less than water. Decaying bodies create internal gas which causes bloating and increases the buoyancy and therefore their freeboard (the area subject to windage). Sea water temperature of 29°C accelerates this process.
Other materials found will drift with a hybrid of water current and wind - depending on their density, the shape, and the proportion above the water to catch the wind.
The galley cabinet, Vertical Stabilizer, seat cushions etc.. are items that were subject to significant windage. The V/S presented a difficult case, as its rudder was hard to starboard (35°) due to the center of buoyancy and the attitude adopted in its floating mode. The V/S not only exibited leeway due to windage, but it was quite capable of "tacking" (to use a nautical term) in certain wind conditions.
Kerosene floats on top of the water and hence its drift will be significantly wind effected - far more so than bodies.
Wind friction on the sea surface is only a fraction of that exerted on an object 2m above the surface. However, you are right, the oil floats and its adhesion to the sea surface is the only dampening factor when confronted with wind on its top surface.
We don't know if the pollution was Jet A1 or not. Was it ever tested to determine its nature?
The Pollution Spot was identified by satellite radar imagery 30 hours after the suspected crash. It was only seen once due to orbit geometry. The satellite evidence was only found following extensive research well after the event, consequently physical examination was not possible.
I imagine that oil from a ship would be much heavier than Jet A1.
Jet A1 has an SG in the range of 0.78 ~ 0.84, Marine Desiel / Gas Oil is 0.84 ~ 0.92, and Bunker Fuel / Heavy Oil 0.92 ~ 0.98 subject to temperature.
If the fuel was from AF447, the ENE winds suggest the impact was upwind of this. That is hard to reconcile with:
a) bodies drifting in a sea-current to the NE and then the N, suggesting the impact was further west
b) where the authorities have searched so far
So how certain are we that the sea current was initially NE?
SaturnV has re-posted data from the NOAA-OSCAR project, and coupled with QuikScat satellite 2m wind data, it is/has been possible to backtrack to the south and west of where the bodies were initially sighted.
Of course the current may have changed over time or distance or both, and equatorial currents are especially fluky. So there is plenty of guesswork here. You can't simply extrapolate back southwards til time zero.
I don't think anyone is extrapolating on a constant time versus distance basis. There has been plenty of detailed work presented in this thread and in the old AF447 thread (about 6,900 posts) which covers backtracking based on the limited information that is available.
Of course if the current had been constant (and I am not sure that we know it was not), then the bodies track back pretty much exactly to a point 1-2 days wind drift ENE of the "pollution" spot.
FluidFlow demonstrated mathematically that the Pollution Spot was a position of interest, but as you mention the vagaries of the North Atlantic equatorial currents and winds tend to make that assumption purely theoretical.
So did the plane turn to the right (and not the left) after encountering severe turbulence beyond the last known point?
Not actually relevant, as evidence has been presented by the BEA that proves that other aircraft flying the same and an adjacent airway that night took the appropriate wx avoidance after observing what was ahead on their wx radar. Some went left and some went right, and I don't think that where the nearest land was or comms difficulties with Dakar Oceanic or Atlantico made any difference.
Finally, I've gathered a lot of data from varied sources on the Equatorial North Atlantic surface currents, and can without doubt state that giving a Chimpanzee a pencil and asking him to write his name could possibly reveal where the surface current had been previous to the first sighting on 05 June back to around 0215z on 01 June 2009.
mm43