Optimising ocean gliders for near-surface measurements (MATTHEWSUENV17NEX)

Project Rationale
The detailed vertical structure of the ocean near its surface has a major impact on how the ocean exchanges heat and momentum with the atmosphere, which then affects weather and climate. However, this near-surface structure is difficult to measure accurately with conventional oceanographic observations.
The recent proliferation in the use of ocean gliders has provided a potential new data source of these near-surface measurements. Gliders are ideally suited to measure near-surface ocean characteristics, as they are streamlined and free flying, and do not disturb the delicate near-surface structures they are attempting to measure. For example, recent glider observations in the Indian Ocean have revealed the detailed structures of diurnally formed surface warm layers in the upper few metres of the ocean. However, gliders are normally ballasted and optimised for flight at mid-depths.
Together with the standard parameters used for surface manoeuvres at the beginning and end of each dive, the glider flight characteristics are sub-optimal for obtaining the best possible near-surface measurements. This project will investigate the effect of optimising glider flight characteristics on the quality of near-surface measurements.

Methodology
The student will liaise with all glider missions run out of UEA and SAMS during the project. Once each glider is correctly trimmed and is gathering high quality data, a small number of dives will be used to evaluate the improvement in near-surface data to changes in a number of glider flight parameters (associated with general flight and near-surface manoeuvres). A glider mission typically generates 500-1000 dives, so this will not be detrimental to the overall mission.
The student will also be part of the piloting team in each of these missions. In parallel, the student will use the large data base of glider dives already generated by the UEA and SAMS glider groups, to evaluate the effect of glider flight parameter changes on near-surface data quality from historical missions. A set of recommendations will be developed, to optimise both near-surface measurements but at minimal cost to the quality of deeper measurements. The science questions to be addressed are the formation of surface diurnal warm layers, barrier layers, and near-surface mixing processes, and their impact on ocean-atmosphere fluxes.

Funding Conditions
This NEXUSS CDT studentship is fully funded by NERC through the National Productivity Investment Fund (NPIF) for the period of 3 years 8 months. An annual stipend (£14,553 for 2017-18) will be available to the successful candidate who meets the UK Research Council eligibility criteria. These requirements are detailed in the RCUK eligibility guide which can be found at http://www.rcuk.ac.uk/documents/publications/traininggrantguidance-pdf . NERC has, exceptionally, relaxed the residential eligibility rule for NPIF studentships, therefore the award may be made to an international candidate if justification can be made that it has not been possible to recruit a UK candidate. This appointment will be subject to approval by NERC. A successful international applicant will be eligible for a full award paying tuition fees and maintenance.

Training
The NEXUSS CDT provides state-of-the-art, highly experiential training in the application and development of cutting-edge Smart and Autonomous Observing Systems for the environmental sciences, alongside comprehensive personal and professional development. There will be extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial / government / policy partners.
The student will be registered and hosted in the Centre for Ocean and Atmospheric Sciences (COAS) at UEA in Norwich but will spend time based at SAMS in Oban working with engineers to share best practice for glider operations. Specific training will include:
• ocean glider piloting, operation, and data analysis
• oceanography, ocean dynamics, ocean physics
• computing and processing of large data sets
• seagoing and marine data collection skills
• use of glider hydrodynamical models use for optimising glider flight characteristics and near-surface measurements