PhD Taking LTER HAUSGARTEN time-series analysis to a new level

Holistic time-series studies of arctic marine ecosystems are rare. This is not surprising since polar regions are largely only accessible by means of expensive modern infrastructure and instrumentation. In 1999, the Alfred Wegener Institute, established the LTER (Long-Term Ecological Research) observatory HAUSGARTEN, crossing the Fram Strait between Greenland and Svalbard to detect and track the impact of large-scale environmental changes on the marine ecosystem in the transition zone between the northern North Atlantic and the central Arctic Ocean. Multidisciplinary investigations cover major parts of the open-ocean ecosystem. They are carried out at more than 20 permanent sampling sites in water depths ranging between 250 and 5500 m (Soltwedel et al., 2016). From the outset, repeated sampling in the water column and at the deep seafloor during regular expeditions is complemented by continuous year-round sampling and sensing. Measured parameters cover a very broad trans-compartmental spectrum. It ranges from remote sensing data for sea-ice coverage and primary production, variations in the hydrography, SST variations, transport processes of organic matter to the deep sea and the effects of those changing processes on marine communities.

Aim and Tasks

The vast data set from this ecological time-series comprises a temporal component, generated over twenty years, and a spatial component for each year investigated. By now, we have not yet sufficiently succeeded in statistically combining the large number of investigated parameters in a way it would allow to derive direct or indirect dependencies between those parameters. Based on the design of the monitoring study the project will be divided into three main aspects, each of them aiming to find the best possible statistical method to assess if respective gradients have an effect only on individual parameters or directly on a whole set of parameters.

• Statistical analysis of the time-series component using Dynamic Factor Models (Dickhaus and Sirotko-Sibirskaya, 2019) in combination with statistical change point detectionto identify time periods of biological or climate regime shifts,
• Application of Copula Models to investigate special dependencies and structures (Neumann et al., 2019 and the references therein),
• Amalgamation of key findings of the two previous tasks (Kröncke et al., 2019) and application on high-resolution remote sensing spatial data to interpolate parameters sampled with lower spatial resolution and frequency.

Requirements

• You should have a solid background in mathematics with programming skills and statistics with emphasis on time-series analysis and pattern detection methods.
• A true motivation to work with different disciplines of climate and ecological sciences is desired.

More Information

More information can be found at
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MarDATA, a graduate school financed by the Helmholtz Association, will define and educate a new type of “marine data scientists” by introducing and embedding researchers from data science into ocean sciences–from supercomputing and modelling, (bio)informatics, robotics, to statistics and big data methodologies. Researchers from the German leading institutes for marine research, the GEOMAR Helmholtz Centre for Ocean Research Kiel and the Alfred-Wegener-Institute (AWI) Helmholtz Centre for Polar and Marine Research, will jointly educate and supervise doctoral candidates together with information & data science specialists from their partner universities in Kiel (Kiel University) and Bremen (Universität Bremen and Jacobs University).

The broad education in joint block courses, international summer schools and colloquia will go beyond a single discipline towards genuine scientific insight into and a more systematic treatment of marine data.

Equal opportunities for women and men are an integral part of our personnel policy. Therefore, we encourage women to apply.
Disabled applicants will be given preference when equal qualifications are present. The AWI fosters the compatibility of work and family through various means. Because of our engagement in the area of work-life compatibility we have been awarded the certificate “Career and Family”.

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