Multi-Scale Assessment of Nighttime Light Attenuation and Modeled Coastal Skyglow Extent Over Marine Areas in Bohai Rim Coastal Cities

Artificial light at night (ALAN) from coastal cities threatens adjacent marine ecosystems, yet no framework systematically characterizes how urban nighttime light contributes to skyglow across the land–sea interface at multiple scales. Marine light pollution operates through three mechanisms – direct illumination, reflected glare, and atmospheric skyglow – of differing spatial extent: the former two affect mainly the near-shore zone (within a few kilometers), whereas skyglow extends over distances relevant to regional coastal management. This study addresses the skyglow component by integrating satellite remote sensing, ground measurements, and land–sea impact assessment for five Bohai Rim cities (Dalian, Yingkou, Panjin, Jinzhou, and Huludao). Using NPP/VIIRS data and concentric-zone analysis, inverse-function attenuation models were constructed for all cities (R2 > 0.72), yielding influence ranges of 10–20 km that varied with urban morphology. Ground measurements across functional zones showed that commercial areas produced the most severe light pollution, with upward light affecting 87.5% of the zenith hemisphere versus only 25% in agricultural areas. A linear regression linking distance-binned illuminance to season-matched VIIRS monthly radiance (R2 = 0.71, p < .001) confirmed a consistent ground–satellite association. Using skyglow extent models (R2 > 0.82), maximum modeled coastal skyglow extents of approximately 14 km (Dalian) and 12 km (Yingkou) were determined. These extents represent atmospheric skyglow footprints, not direct measurements of sea-surface irradiance. Dalian’s maximum modeled coastal skyglow extent originated from commercial districts and Yingkou’s from peripheral industrial areas, indicating that mitigation must be city-specific. A three-tier coastal lighting management framework is proposed.