C-Index Analysis of Ground-to-Satellite Cloud Observation Coherence

04-26-2026: The frameworks and concepts originate from the author's observation and pattern recognition. Large language models served as articulation and stress-testing tools throughout development. No changes made aside from the addition of this disclosure. This field note applies the C-Index metric from the published Coherence Triad framework (Kristenson, 2024; DOI: 10.5281/zenodo.18207855) to the NASA-CAP 2025 Aviation Weather Mission dataset for June 14, 2025 (DOI: 10.5281/zenodo.18836489). The C-Index, a substrate-independent measure of internal alignment quality, is operationalized as the normalized mean absolute deviation between ground observer cloud cover reports and collocated GOES satellite-derived cloud cover percentages across 132 paired observations. The overall C-Index is 0.746, placing the ground-satellite collocation system in the moderate coherence band. A pronounced regional pattern emerges: arid interior Western regions (Arizona, New Mexico) reach C = 0.944 to 0.969, while Southeast Atlantic coastal zones (North Carolina, coastal Georgia) collapse to C = 0.111 to 0.314. The partial cloud cover regime yields the highest coherence (C = 0.906), consistent with known satellite retrieval limitations at low cloud density documented by the NASA GLOBE Clouds team. A persistent coherence deficit is identified at the contrail-altitude layer for an observer tracking active contrails across three consecutive observation windows. Findings are preliminary, limited to a single mission date, and are offered as a methodological contribution to observer-satellite coherence characterization. The C-Index framework explicitly defers physical interpretation of regional patterns to domain experts.