The Commonwealth Scientific and Industrial Research Organisation (CSIRO) published four reports describing oceanographic drift modelling work done in aid of the search for MH370.
The first report identified the 36°-32°S segment of the 7th arc (especially the region near 35°S) as being the most likely site of the impact, based on where and when debris was seen and not seen on African and Australian shores and during the initial 40-day aerial search (Fig 1.1). This work was a contribution to the First Principles Review ATSB (2016).
The 2nd report documented additional research recommended by the First Principles Review using a real Boeing 777 flaperon, rather than a replica. The CSIRO measured its drift characteristics after modifying it to match the damaged one retrieved from Ile de la Reunion. This work did not change the CSIRO's estimate of the most likely location of the impact – it just increased confidence in the modelling by explaining more easily the 29 July 2015 Ile de la Reunion flaperon discovery.
The third report discussed the implications, in terms of locating 9M-MRO, of analyses by Minchin et al. (2017) of some ultra-high resolution (meter-scale) optical images acquired in March 2014. This showed that items seen in the images could very well have been within the southern half of the proposed (36°-32°S) search region, but not the northern half. Recalling that the CSIRO had already identified this southern half as being more prospective, this extra information gave an additional measure of confidence.
The 4th report revisited the effectiveness of the surface search. To what extent did it rule out various areas as being the location of MH370? In particular, the CSIRO partially relied on the surface search to argue that the aircraft is less likely to be north of 32°S than south of 32°S. Other factors were that 1) travel times to Africa are progressively less for more northern sites, so absence of debris findings before December 2016 become harder to explain, and 2) simulated flight paths terminating north of 32°S are progressively less consistent with SATCOM data.