So Lee's team used a computer model to explore the fate of the ocean's 'missing heat'. The results suggest that easterly trade winds have strengthened during the hiatus, causing warm water to pile up in the western Pacific. The water seeps between the islands of Indonesia and into the Indian Ocean, bringing heat with it.
In the model, this surge of water produces dramatic warming in the upper Indian Ocean starting in the early 2000s, in agreement with the WOA data, the authors write. This explanation also fits with measurements of flow through the largest Indonesian channel — the Makassar Strait — which increased over the same period of time.
http://www.nature.com/news/indian-ocean-may-be-key-to-global-warming-hiatus-1.17505