The Research Infrastructure (RI) ACTRIS – Aerosols, Clouds and Trace Gases - is the pan-European RI that consolidates activities amongst European partners for observations of aerosols, clouds, and trace gases and for understanding of the related atmospheric processes, to provide RI services to wide user groups. ACTRIS is composed of 8 connected elements: distributed National Facilities (observation platforms and exploratory platforms) both in Europe and globally, and 7 Central Facilities (Head Office, Data Centre and 5 Calibration Centres). ACTRIS provides access to its facilities, open-access data, research support, instrument calibration and development, and training to various user groups. By providing data and access ACTRIS enhances science, but it also generates and disseminates knowledge, boosts technological development, and creates human capital and jobs for the benefit of the society. ACTRIS will positively impact on e.g. human health, climate resilience, and protection from environmental hazards and reduction of air pollution. ACTRIS has been selected to the ESFRI roadmap in 2016 as mature enough to be implemented within the next ten years. ACTRIS Preparatory Phase Project (PPP) will have a significant role in enabling the transition from a project-based network of research facilities to a centrally coordinated integrated pan-European RI. ACTRIS PPP brings together a wide community of research performing organizations, research funding organizations and ministries needed to take the decisions and actions to move forward in the implementation of the ACTRIS. The main objectives of ACTRIS PPP are to develop the organizational, operational and strategic frameworks of the RI. The work includes legal, governance, financial, technical, strategic, and administrative aspects carried out in 9 work packages. The main outcomes of PPP are signature-ready documents for establishment of a legal entity with well-defined operations and a sound business plan.

ACTRIS-2 addresses the scope of integrating state-of-the-art European ground-based stations for long term observations of aerosols, clouds and short lived gases capitalizing work of FP7-ACTRIS. ACTRIS-2 aims to achieve the construction of a user-oriented RI, unique in the EU-RI landscape. ACTRIS-2 provides 4-D integrated high-quality data from near-surface to high altitude (vertical profiles and total-column), relevant to climate and air-quality research. ACTRIS-2 develops and implements, in a large network of stations in Europe and beyond, observational protocols that permit harmonization of collected data and their dissemination. ACTRIS-2 offers networking expertise, upgraded calibration services, training of users, trans-national access to observatories and calibration facilities, virtual access to high-quality data products. Through joint research activities, ACTRIS-2 develops new integration tools that will produce scientific or technical progresses reusable in infrastructures, thus shaping future observation strategies. Innovation in instrumentation is one of the fundamental building blocks of ACTRIS-2. Associated partnership with SMEs stimulates development of joint-ventures addressing new technologies for use in atmospheric observations. Target user-groups in ACTRIS-2 comprise a wide range of communities worldwide. End-users are institutions involved in climate and air quality research, space agencies, industries, air quality agencies. ACTRIS-2 will improve systematic and timely collection, processing and distribution of data and results for use in modelling, in particular towards implementation of atmospheric and climate services. ACTRIS-2 invests substantial efforts to ensure long-term sustainability beyond the term of the project by positioning the project in both the GEO and the on-going ESFRI contexts, and by developing synergies with national initiatives.

The Danube River Basin (DRB) faces significant challenges associated with river sediments. In the 2021 update of the Danube River Basin Management Plan, sediment balance alteration emerged as a new sub-topic within the existing Significant Water Management Issue titled "Hydromorphological alterations." Additionally, sectors like industry, urban sewage, and agriculture call for sediment quality evaluations throughout the DRB. However, the absence of standard sediment monitoring limits our understanding of risks. Addressing the sediment mismanagement in the DRB, the iNNO SED project aims to establish the Danube Sediment ‘Lighthouse’ Knowledge Centre. This centre will: • Introduce a set of innovative methods for monitoring and modelling sediment quantity and quality, thereby deepening our knowledge of sediment processes. • Provide innovative sediment management practices to improve sediment continuity and quality in DRB sections facing with sediment-related issues. • Showcase co-created innovative measures through demonstration activities, while also evaluating their socio-economic and environmental aspects. • Empower the public with innovative knowledge transfer methodologies. • Collaborate with five Associated Regions, transferring the iNNO SED solutions to other river basins. To accomplish these goals, iNNO SED will leverage the achievements and key contributors of the DanubeSediment and SIMONA initiatives. Moreover, it will engage relevant stakeholders of sediment management, such as ICPDR, policy makers, river managers, hydropower plant managers, waterway authorities, national parks, environmental agencies, SMEs, and more. iNNO SED will represent a pioneering approach to sediment management in large international river basins. This approach sets an example for other major global river systems like the Amazon, Mekong, or Niger. In doing so, it aligns with the Mission's objective of intensifying the European Union's competitiveness.