Pulleniatina sample weights U1486. Grant abstract: This grant supports the participation of UK scientists Professor Paul Pearson in Expedition 363 of the International Ocean Discovery Program which plans to study the history of the 'Indo-Pacific Warm Pool' over the last 15 million years. It includes costs to cover his time while on board ship (2 months at sea) and post-expedition scientific study. Sea surface temperatures exceed 28oC across a huge area of the tropical western Pacific and Indian Oceans. Known as the Indo-Pacific Warm Pool (IPWP), this area is fundamental to the global atmospheric circulation and hydrologic cycle. The IPWP is intensifying with global warming, but modelling its likely future is challenging. Expedition n363 aims to study its temperature and climatic history over the past 15 million years, including through glacial to interglacial climate cycles and back to the globally warm Miocene epoch. Understanding its past history will help determine if its current temperature is near to its likely maximum or if global warming can cause much greater intensification in the future. Professor Pearson is a specialist in the study of microscopic fossils called planktonic foraminifera. He will study the evolution of the ocean plankton in the region over the study period, in relation to climatic change and sea level fluctuations which greatly affect the distribution of land masses and shallow seas and hence ocean current patterns. The foraminifera are also used to determine the age of the sediments drilled (called biostratigraphy) and providing other expedition scientists with a high quality planktonic foraminifer biostratigraphy will be one of the main features of this project. In additional there is a particular focus on an evolutionary lineage of foraminifera called Pulleniatina which has considerable untapped potential for stratigraphic work and also as a case study in the detailed speciation and extinction of a group of plankton. Study of this group will be facilitated by the large populations and varying morphology exhibited by them and because, like snails, they can be left or right handed and the pattern of coiling through time and across space is highly complex and potentially very informative.