• Project
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Overview

Monsoons are a major characteristic of SE Asian climate bringing millions of litres of water to the region and impacting over a billion people annually. In particular, the northern Indian Ocean is the Earth’s strongest hydrological region, involving large inter-hemispheric exchanges of mass and energy between the ocean, atmosphere and continents [1]. The exchange results in seasonal monsoon winds in the Arabian Sea, and precipitation in India and surrounding areas. The monsoon ultimately delivers surface runoff into the Bay of Bengal (BoB) resulting in seasonal changes in surface ocean salinity and currents due to wind forcing.

 

The overall aim of this project is to reconstruct seasonal changes in Indian Summer Monsoon (ISM) precipitation through the Plio-pleistocene (~0-5 Myrs ago) using a suite of state-of-the art organic geochemical tracers of run-off from the major river systems of the Indian subcontinent. This project will investigate organic matter runoff using well-established biomarker proxies as well as help to develop and apply the newer R’soil proxy [2]. The student will use samples recently recovered by International Ocean Discovery Programme (IODP) Expedition 353 and will link the organic data to complementary foraminiferal data currently being produced at the Open University (OU). These data will be used to determine the dominant control(s) on the ISM, e.g., external (e.g., insolation) vs internal climate forcings such as global ice volume, southern hemisphere temperature change and greenhouse gas concentrations.

Figure 1: Sediment plume enters the Bay of Bengal from the Ganges-Brahmaputra (top right) and Mahanadi (bottom left) rivers. The image is from the NASA MODIS instrument with the snow capped Himylayas arcing over the top of the image.

Methodology

Deep-sea sediments from IODP Expedition 353 will be solvent extracted and, following wet chemistry column chromatography, analysed by GC-MS, LC-MS and LCMS-TOF to determine biomarker ratios. GC-MS and LC-MS analysis will be performed at the Open University, with LCMS-TOF analysis carried out at Manchester Metropolitan University (MMU) with R. Sparkes. Biomarker ratios will be used to determine sediment runoff and climatic conditions via the BIT index, TEX86, MBT/CBT and R’soil [2]. Samples for bulk organic carbon isotope analysis (δ13Corg) and C/N ratio will be prepared and analysed by EA-IRMS at OU. K Littler will provide Pliocene benthic foraminiferal stable oxygen isotope and other organic geochemical data for comparison with the new data set generated here.

Training and Skills

The student will be trained in advanced organic geochemistry techniques including organic clean lab extractions, column chromatography and solvent handing techniques. Training will be provided in analysis using hyphenated techniques (GC-MS, LC-MS, LCMS-TOF) in the state-of-the-art laboratories at the OU and MMU. The student will acquire significant skills in organic biomarker analysis, identification and interpretation. Further training will include:

Data handling and interpretation from a wide variety of data sources.

Scientific communication through writing, poster and oral presentations to academic and non-academic audiences.

Online teaching opportunities via the Open University Virtual Learning Environment are also available, including teaching on the new Massive Open Online Courses (MOOCs).

NERC CENTA students are required to complete 45 days training throughout their PhD including a 10 day work placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes. 

Timeline

Year 1: Literature review and processing Holocene core material to establish baseline run-off and climate variability. This will include sample preparation and data collection from bulk organic samples and training in organic geochemistry extractions.

Year 2: Extraction and processing of Pleistocene core material and analysis of sample extracts by GC-MS, LCMS (at OU). Pilot data and techniques developed for R’soil analyses at MMU. Comparison of data with existing records, possible generation of new Pliocene data. Preliminary data will be presented at a UK conference.

Year 3: Completion of remaining analyses at OU and LCMS-TOF analyses (at MMU). Present major findings at international conference and to IODP Exp. 353 stakeholders.

Partners and collaboration (including CASE)

The student will join the international team of IODP Exp. 353 scientists, and will benefit from collaborations with other PhD students currently working on Exp. 353 samples within CENTA and at other institutions globally.

Further Details

Students should have a strong background in paleoclimate and enthusiasm for geochemistry. Experience of labwork and knowledge of organic geochemistry is highly desirable. The student will join a well-established team researching paleoenvironmental change at the Open University.

If you would like further information please contact Marcus Badger using the information above. 

Applications should include:

 Applications should be sent to

STEM-EEES-PhD-Student-Recruitment@open.ac.uk  

by 5 pm on Monday 22nd January 2018