Bridging environmental data providers and SeaDataNet DIVA service within a collaborative and distributed e-Infrastructure

Among its devastating effects, ocean acidification harms organisms whose life depends on shells and on coral reefs. Therefore, it affects important marine ecosytems hosting high biodiversity and food availability. A recent paper published on Nature has highlighted the decrease of calcification of a very important planktonic mollusc, the sea butterfly (Limacina helicina). The shell-building capacity of this organism declines with decreasing aragonite saturation, which is due to the increase of average pH in the seas. Monitoring and containing ocean acidification helps preventing coral reefs and shell-building organisms to dissolve, and thus helps preventing ecological disasters. Unfortunately, environmental observations of parameters like aragonite saturation and pH are usually available as scattered in situ data, published on restricted-access data e-Infrastructures (e.g. the Copernicus Marine Environment Monitoring Service). On the other hand, interpolation services exist (e.g. the SeaDataNet Data-Interpolating Variational Analysis service, DIVA) to estimate global, uniform distributions of environmental parameters from scattered observations. However, these services usually require data to be compliant with a non-standard format and cannot accept in situ data formats directly. Furthermore, they do not support facilities neither to communicate nor to publish their results for a large public. The D4Science e-Infrastructure is a distributed computer system that aims at supporting large-scale resource sharing (both hardware and software) via the definition of Virtual Research Environments (VREs) and allows data to be processed with distributed computing. D4Science is able to create a bridge between several e-Infrastructures to fill the communication gap between them. This bridge is realised through a set of data storage and processing web services that are easy to extend. As for the ocean acidification monitoring case, we present a D4Science process (D4Science-SeaDataNet Interpolator service) that can transform a set of Copernicus in situ marine observations of an acidification parameter into a uniform global distribution map, published on a data catalogue under standard geographical representation formats (e.g. Web Map Service, Web Feature Service, Web Coverage Service). This process is hosted on the D4Science computing platform, which uses also European Grid Infrastructure FedCloud resources, and is able to (i) import Copernicus observations, (ii) organize them into a suitable format for the SeaDataNet interpolation service, (iii) execute the interpolation process and (iv) publish or share the output as a gradient map. The process invokes the SeaDataNet DIVA interpolation service using a distributed computing strategy to process both the input and output. Finally, the e-Infrastructure provides a geospatial services network, on which the computing system can store and publish data as GIS maps. The process is also endowed with a graphical user interface, available through a Web portal (i-marine.d4science.org). Through D4Science, users can establish the access policy for the input and output data, e.g. they can share data either with selected colleagues or with all the participants to a Virtual Research Environment they are involved in.