Integration of mercury atmospheric models in a framework for interoperable workflow execution

The focus of this work has been on increasing interoperability of the mercury models developed at CNR/IIA, by harmonizing them according to the GEO Model Web initiative and the Brokering approach. The work is done in the context of Earth and Space Sciences (ESS), where many actors need to interoperate, such as research groups, decision makers and private companies along with their many heterogeneous software systems and information models: it's the interoperability challenge. In this context international programs and organizations have the role of coordinating and easing such interoperability efforts, e.g. drafting guidelines, promoting standardization and implementing infrastructures: - The GEO Model Web initiative envisions an increased interoperability of ESS computational models, which will become online available and interoperable, allowing chaining and complex workflows, as well as multidisciplinary applications (Nativi, Mazzetti, & Geller, Environmental model access and interoperability: The GEO Model Web initiative, Environmental Modelling & Software, 2013) - The Brokering approach emerges with the aim of easing interoperability between heterogeneous parties (Boldrini, Craglia, Mazzetti, & Nativi, 2014): an important implementation of this approach is to be found in the Group on Earth Observation Discovery and Access Broker (GEO-DAB) which takes charge of discovering and accessing millions of geospatial resources around the globe and presenting them in a user friendly way (Group on Earth Observations, 2014) CNR/IIA modelers working at the Rende division have produced mercury atmospheric models in the context of the Global Mercury Observation System (GMOS) (Cinnirella, D'Amore, Bencardino, Sprovieri, & Pirrone, 2014) based on the Weather Research and Forecasting Model (WRF) to gain deeper knowledge about this pollutant cycle (Gencarelli, De Simone, Hedgecock, Sprovieri, & Pirrone, Development and application of a regional-scale atmospheric mercury model based on WRF/Chem: a Mediterranean area investigation, 2014). In particular by adopting and enhancing the Business Process-Broker framework developed by researchers of the CNR/IIA Florence division, it has been possible to make the mercury models online available and more interoperable. The BP-Broker is capable of interpreting custom workflows described using the Business Process Model and Notation (BPMN) and executing them after resolving the needed resources (e.g. models, input data) by leveraging the brokering approach. Once integrated in the BP-Broker framework, mercury models can be remotely configured and executed by scientists: a user friendly portal has been implemented and deployed, to ease accessibility to the BP-Broker and make possible demonstration of the functionalities of the full e-WRF/Chem-Hg system. Moreover, the models become readily available as building blocks for realizing and executing complex workflows designed using standard BPMN diagrams as well. Composition of WRF/Chem-Hg BP in complex workflows has been demonstrated by designing and executing an additional workflow which includes chaining of the mercury model to a post processing service. By adopting Model Web and the Brokering approach, not only interoperability and accessibility is increased, but also repeatability of experiments: both human users and machine clients can now access the e- WRF/Chem-Hg system to reproduce the results found in the literature.