Comparing ground-temperature records across depth and siting

Ground-temperature records can acquire apparent changes when sensors move, depths change, or surface conditions differ. This methods note synthesises a documented Arctic borehole dataset, permafrost-network metadata, and measurement-uncertainty guidance to examine when records are comparable. It distinguishes instrumental transfer from relocation between environments and explains why depth changes both seasonal sensitivity and response time. Fictional worked cases show how joining two individually valid records can introduce a step, and how depth uncertainty enters a temperature budget. The note recommends preserving comparable record segments, overlap evidence, and adjustment assumptions rather than forcing visual continuity. It estimates no regional trend and provides no universal depth correction or minimum overlap. Its contribution is a practical framework for keeping continuity of meaning visible when an observing system changes.