Vacancies
Expressions of interest are opened for two PhDs projects
Remote Sensing of phytoplankton diversity using cutting-edge satellite ocean colour techniques
Project Overview
Phytoplankton – the microscopic photosynthesizing algae inhabiting the surface sunlit layers of the oceans, are responsible for the production of around 50 billion tons of organic carbon per year in the World oceans, which is about half the total Planet primary production. Phytoplankton are highly diverse, and different species have specific roles in the ecosystem and different carbon sequestration efficiencies. As a result, identifying phytoplankton functional types (PFTs) from space became a major endeavour of the international ocean colour community for over two decades, with the development of various models to derive synoptic maps of PFTs from satellite imagery. However, there is still a strong need for the validation of these approaches across a large range of marine ecosystems, and in particular for their implementation in coastal waters.
Aims
The recent availability of a 20-year record of concurrent in situ bio-optical datasets and multi-spectral satellite imagery in coastal and oceanic waters around Australia makes this goal now accessible through the Australian Ocean Data Network (AODN) portal and the IMOS Satellite Remote Sensing facility (SRS) archives. The SRS facility provides satellite remote sensed marine products from NASA’s MODIS sensor and ESA’s MERIS and OLCI sensors. AODN and the SRS facility are part of the Integrated Marine Observing System (IMOS), a national collaborative research infrastructure operated by a consortium of institutions and funded by the Australian government. Through IMOS, we can now observe, monitor, simulate and understand the long-term impacts of human activities and climate change on coastal environments, marine ecosystems and biodiversity.
Objectives
For this research project, the PhD candidate will use the IMOS in situ bio-optical database and the SRS facility remote sensing imagery archives to:
1- Examine existing numerical inversion algorithms, and develop new ones when required, for the detection and mapping of PFTs from space. This first phase will rely on observations at two established sites on the West and East coasts of Australia:
i. In tropical waters at the Lucinda Jetty Coastal Observatory (LJCO, in the Northeast of Australia), where CSIRO maintains a calibration/validation site since 2014. LJCO is the only long-term permanent validation site in the Southern Hemisphere.
ii. In temperate waters off Perth (Western Australia), where the Curtin remote sensing team has deployed a Thetis profiling mooring off Rottnest Island in 2017/2018 (deployments done from spring to autumn due to safety concerns in winter). The Thetis instruments package provides critical field data for quantifying changes in water quality and in support to the validation of ocean colour products from ESA’s Sentinel 3A OLCI sensor.
The seasonality and phytoplankton types at these two sites differ widely, providing a large range of conditions for algorithms validation and development.
2- Validate the methods developed in phase 1 across a wide range of Australian ecosystems characterised by diverse phytoplankton communities, from coastal waters to the open ocean, and from temperate regions to the tropics. This second phase will give access to detailed maps of phytoplankton diversity around Australia using state-of-the-art ocean colour remote sensing techniques. In addition, the candidate will explore the use of machine-learning techniques and their potential for application to the Ocean Colour Instrument (OCI) on NASA’s PACE mission (Plankton, Aerosol, Cloud, ocean Ecosystem mission). OCI is a hyper-spectral sensor (5 nm spectral resolution) with a broad spectral range, from ultraviolet to shortwave infrared light, and thus providing access to unprecedented detailed information on coastal and open ocean ecosystems.
The work done as part of this PhD project may also benefit the AquaWatch Australia data analytics platform currently implemented to deliver a comprehensive water quality monitoring system for coastal, estuarine and inland environments. AquaWatch brings together a consortium of industry and government actors (including CSIRO and Curtin University) in order to develop Australia wide in situ monitoring and remote sensing capabilities.
3- Build an almost 20-year climatology of phytoplankton abundance and diversity for key selected regions in order to:
i. Explore the spatial and seasonal trends in the phytoplankton community structure in contrasted systems around Australia.
ii. Examine the environmental and anthropogenic factors driving changes in phytoplankton communities across a wide range of scales.
Significance
This cross-disciplinary research project, combining cutting-edge remote sensing and machine-learning techniques, will support ecosystem models and provide assessment tools of Australian marine ecosystems functioning and their carbon sequestration efficiency.
Wider applications relevant for the Australian community include coastal water quality and ecosystem health monitoring, and water resources and fisheries management programs.
Internship
Options: CSIRO
Ideal Candidate
We are seeking a graduate from environment physics / environmental sciences. Ideally some background in oceanography and satellite remote sensing.
The applicant would be interested in (and motivated by) current questions about how ocean environments and ecosystems are currently changing in response to climate change, and the impact on the global carbon cycle and marine food webs.
Plus:
- English language IELTS level as per Curtin requirements for Higher Degree by Research applicants (6.5 overall, with a minimum of 6 in each category: Speaking, Writing, Reading, Listening).
- Skills in scientific data processing (e.g., familiarity with Python, R, Fortran, C, GMT, etc.)
This project is open to domestic and international applicants.
Scholarships at Curtin
Explore Scholarship opportunities available to HDR students at Curtin. If you are identified as the preferred candidate for this project, you may be considered for an RTP scholarship.
Undertaking a predefined Higher Degree by Research project is your chance to help turn new discoveries into real solutions. Learn more about Higher Degree by Research | Curtin University and the RTP Scholarship process.
Enquiries
If this project interests you, contact Professor David Antoine via the Expression of Interest.
In search of long-term climate-change-driven trends in ocean phytoplankton
Project Overview
Phytoplankton are the microscopic photosynthesizing algae inhabiting the surface sunlit layers of the oceans. They form the basis of all oceans’ life, produce more oxygen than all terrestrial plants and sustain global fisheries. They are quantifiable using satellite ocean colour radiometry (OCR) because they modify the spectral composition of the light outcoming from the ocean and reaching the satellite sensors. Better quantifying their trends is crucial to understand past changes in this fundamental basis link of the entire ocean ecosystem, then contributing to predict their future response to a globally changing ocean environment. To achieve this goal, one requires satellite observations that are consistent over long periods of time, which is achieved through a process called “System Vicarious Calibration” (SVC). Curtin’s Remote Sensing and Satellite Research Group is in charge of an infrastructure delivering data used for this SVC process, called MarONet (see below).
Some details on what “Satellite Ocean Colour Radiometry (OCR) System Vicarious Calibration (SVC)” is:
OCR-SVC is a relative radiometric calibration of satellite ocean colour sensors that minimizes uncertainties in the water-leaving radiance, Lw, derived from the total radiance measured at the top of the atmosphere, Lt. This is achieved by applying gains to pre-launch absolute radiometric calibration coefficients of the satellite sensor. The gains are determined by the ratio of simulated to measured spectral Lt values where the former are computed through radiative transfer using highly accurate in situ Lw measurements and atmospheric models. OCR-SVC is indispensable to meet the highly stringent requirements of OCR data quality, and accordingly has been applied to all NASA satellite OCR missions following agreed general principles.
See this link if you want more details on OCR-SVC: https://ioccg.org/group/vical/
Some details on the MarONet project in general:
The Marine Optical Network, MarONet, has been specifically developed to support the newly launched NASA “Plankton, Aerosol, Cloud, Ocean Ecosystem” mission (PACE), the first global hyperspectral OCR mission. MarONet consists of two identical buoys deployed off Perth on an approximately 6-month roster. They host a new generation of field deployable spectrometers. They are the evolution of the “MOBY” system that NASA used for many years (since 1997) and is deployed in Hawaii. The Perth site was chosen for its often extremely clear atmosphere and its moderate variability of ocean optical properties. The buoy site is complemented by a ground station on Rottnest Island measuring sky radiances for determination of aerosol properties, as part of the NASA AERONET: https://aeronet.gsfc.nasa.gov/cgi-bin/data_display_aod_v3?site=Rottnest_WA_Aus&nachal=2&level=1&place_code=10
See also here if you want more details about PACE: https://pace.oceansciences.org
Aims
This project aims to improve the reliability of multi-decadal climate-change-driven trends of ocean phytoplankton that are derived from satellite ocean colour radiometry observations.
This will be achieved by improving the so-called System Vicarious Calibration techniques currently in use.
Objectives
The general goal will be achieved by combining:
i) data from a new-generation sea-deployable optical system providing reference measurements of the ocean reflectance; this is MarONet.
ii) The Rottnest AERONET site for atmospheric aerosol measurements,
iii) the latest developments in radiative transfer simulations of satellite observations and numerical inversion of radiometry measurements to derive aerosols properties and,
iv) a multi-sensor ocean colour processing workflow that we previously developed.
Significance
The proposed project will create new knowledge and have multiple benefits.
i) New SVC techniques will be developed for hyperspectral sensors like PACE, which are the future of satellite OCR.
ii) The project will help improving data quality of existing or future satellite OCR missions, hence with impact on a huge community of data users worldwide. They include, e.g., state environment departments, fisheries and aquaculture industries, non-governmental organisations, the IPCC (the ecosystems response to further climate change is still a major uncertainty in their assessments), and the science community of course.
iv) More robust information on the response of phytoplankton to their changing environment are also expected. This will allow ultimately better assessing climate-change-related evolution of our oceans’ ecosystems.
Internship
Options for internship are: CSIRO, the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).
Ideal Candidate
Highly capable student with background in the domains here concerned (quantitative, physics-based remote sensing) and excellent data processing / coding skills.
This project is open to domestic and international applicants.
Scholarships at Curtin
Explore Scholarship opportunities available to HDR students at Curtin. If you are identified as the preferred candidate for this project, you may be considered for an RTP scholarship.
Undertaking a predefined Higher Degree by Research project is your chance to help turn new discoveries into real solutions. Learn more about Higher Degree by Research | Curtin University and the RTP Scholarship process.
Enquiries
If this project interests you, contact Professor David Antoine via the Expression of Interest.
Subjects for Curtin 3rd year / Honours students
Possible subjects are displayed below when available but, if you have any other idea that you think might involve satellite remote sensing, please feel free to come and discuss it. We can design a project that suits your interests.
Net Community Production in the Eastern Indian Ocean
Supervisor: Charlotte Robinson
In May-June 2019, the RSSRG participated to a 1-month research voyage on R/V Investigator (see links below), exploring waters of the Eastern Indian Ocean (EIO) off WA, from 40°S to 10S along the 110°E longitude. One objective of the expedition was to study the biological carbon pump at the base of the food chain by measuring the marine microbial primary productivity using radiocarbon isotopes (14C) and net community production with a state-of-the-art equilibrator mass-inlet spectrometer system (EIMS) that measures dissolved oxygen-argon ratios. These measurements, combined with ancillary measurements of temperature, salinity, available light, physical mixing and phytoplankton characteristics such as community composition, size, carbon content and pigmentation will contribute to a mechanistic understanding of carbon export production in the oligotrophic Eastern Indian Ocean. Working with Dr Charlotte Robinson, the student will learn to quality control oceanographic data, compute net community production using the EIMs data and other physical and chemical oceanographic data and contribute to a journal publication on the biological pump and carbon export potential of marine microbes in the Eastern Indian Ocean. Interested students should be comfortable with working in and processing data in Matlab, Python or R.
Options to get research funded in Australia for interested scientists:
Appropriately qualified researchers can apply to a number of competitive funding schemes for individual fellowships, as proposed by Australian funding agencies, such as (non exhaustively):