River-Scale Digital Twin for Cryo-Hydrological Systems: Architecture and Integration Principles from the JÄÄTwin Framework

This contribution presents the system architecture, data pipelines, and modelling logic at a conceptual level for a Digital Twin prototype named JÄÄTwin. The aim of JÄÄTwin is to integrate near-real-time observations from multiple heterogeneous data sources, with numerical models, and computational infrastructure into a live “river ice condition” digital twin. While large-scale initiatives focus on continental and global domains, digital twin implementations at the river scale remain limited, specifically for cryo-hydrological systems. JÄÄTwin integrates in-situ monitoring data, remote sensing products, and meteorological forecast inputs through a modular backend that supports data ingestion, preprocessing, model orchestration, and visualization. The emphasis of this contribution is on system architecture, data integration logic, and operational workflow design.

The Kiiminkijoki River in northern Finland is used as a pilot to demonstrate how a river-scale digital twin can be implemented using existing monitoring infrastructure. The presentation discusses design choices, integration challenges, and transferability considerations relevant to future Earth system digital twin developments and to emerging European digital twin initiatives.