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it shows how standard graph-search methods can be
embedded in a clearly specified environmental-
screening procedure for Arctic navigation studies. This
is useful because many Arctic routing studies focus
directly on optimisation, weather routing, fuel
consumption, or operational decision support,
whereas a route must first be topologically feasible
under basic environmental constraints.
This paper addresses four practical research
questions:
− RQ1. Does a continuous trans-Arctic route between
Rotterdam and Yokohama exist on the selected 0.5◦
pan-Arctic grid when bathymetry constraints are
applied?
− RQ2. How does adding a SIC constraint change
route continuity and corridor selection relative to
the bathymetry-only baseline?
− RQ3. How do selected SIC thresholds and late-
summer dates affect route distance ratio and route
availability in the Rotterdam–Yokohama Arctic
case study?
− RQ4. What assumptions and limitations follow
from using this workflow as a strategic route-
feasibility layer rather than as complete operational
navigation guidance?
The paper is structured as follows. Section 2
positions the study relative to existing Arctic route-
planning work. Section 3 describes the routing domain,
bathymetry data, sea-ice data, and grid construction.
Section 4 defines the feasibility masks, graph
construction, edge costs, A-star search, and sensitivity
setup. Section 5 presents the route-feasibility and
sensitivity outputs. Section 6 discusses interpretation,
limitations, and use in future navigation and digital-
twin studies. Section 7 summarises the findings.
2 RELATED WORK AND STUDY POSITIONING
Arctic route planning has been studied from several
perspectives, including route feasibility, ice-aware
routing, vessel-performance modelling, weather
routing, risk assessment, and decision support. Recent
review work emphasises that Arctic weather routing
depends on both ship-performance models and ice-
routing algorithms, and that the field still requires
transparent modelling choices and clearer treatment of
ice conditions (Liu et al., 2023). Route-View
demonstrates how big Earth data can be used in an
interactive Arctic route-planning system (Wu et al.,
2022). Other studies have addressed Arctic route
design using multi-objective formulations that
combine safety, economic, and environmental criteria
(Chen et al., 2023). Work on icebreaker-assisted routing
also shows that operational Arctic routing can require
additional constraints beyond simple distance
minimisation (Topaj et al., 2019). Economic and
operational studies of the Northern Sea Route further
show that distance reduction alone is insufficient for
assessing practical route attractiveness (Theocharis et
al., 2019).
2.1 Arctic route planning under environmental
constraints
Sea-ice concentration is commonly used as a first
indicator of ice accessibility. In operational navigation,
however, SIC alone is insufficient because vessel
capability, ice thickness, ridging, drift, visibility,
weather, icebreaker support, and regulatory
constraints also matter. The IMO Polar Code and the
POLARIS guidance link polar navigation to vessel
capability and ice-risk assessment rather than to sea-ice
concentration alone (IMO, 2016; PAME, 2024).
Bathymetry is similarly important but incomplete: a
minimum-depth screen is not a full under-keel-
clearance assessment and does not replace nautical
charts. In this paper, bathymetry and SIC are therefore
used as strategic screening constraints, not as complete
safety criteria.
2.2 Graph-based routing and shortest-path methods
Graph-based routing represents a navigable area as
nodes and edges. Once infeasible cells are removed,
shortest feasible paths can be computed by standard
graph-search algorithms. A-star search is appropriate
when a lower-bound heuristic is available. Here, the
heuristic is the geodesic distance from a node to the
destination. Since any feasible path through the graph
cannot be shorter than the direct geodesic distance to
the destination, the heuristic does not overestimate the
remaining distance. A-star is therefore used as an
efficient shortest-path implementation rather than as a
claimed methodological novelty.
2.3 Study positioning
Compared with full weather-routing, vessel-
performance, or ice-risk models, the present study
deliberately focuses on the pre-routing feasibility layer.
Weather-routing models use wind, waves, currents,
and sometimes ice to generate time-, fuel-, or safety-
oriented routes. Ice-routing models may use SIC, ice
thickness, ice charts, and vessel ice capability to
generate ice-aware or risk-aware routes. Vessel-
performance routing uses ship particulars, propulsion,
ice resistance, and metocean state to estimate speed
loss, fuel consumption, emissions, or estimated time of
arrival. Operational decision-support systems use
forecasts, traffic, operational rules, and vessel
constraints to support route advice.
The present workflow does not replace these
approaches. Its purpose is earlier in the analysis chain:
it tests whether a continuous candidate corridor exists
under specified bathymetry and SIC assumptions. Its
value is that the screening choices are explicit: routing
domain, grid resolution, bathymetry threshold, SIC
threshold, graph topology, edge costs, route metrics,
and sensitivity design.
3 DATA AND ROUTING DOMAIN
3.1 Routing domain and endpoints
The routing domain covers 40–85◦N and 20◦W–180◦E.
This domain captures the northern Europe–Asia
routing region and the main Arctic corridor space