Spatial Assessment of Nitrogen Dioxide (NO 2 ) in Lithuania’s Coastal Zones: A Remote Sensing Approach for Sustainable Urban Planning

Nitrogen dioxide (NO 2 ) is a short-lived atmospheric pollutant primarily emitted by road traffic, maritime shipping, and industrial combustion. It is a key indicator of anthropogenic air pollution due to its harmful health effects, its role in the formation of secondary particulate matter, and its strong association with other traffic-related pollutants. Elevated NO 2 concentrations are closely linked to respiratory and cardiovascular diseases, with children and elderly populations being particularly vulnerable due to physiological susceptibility and exposure patterns. This study uses satellite-based remote sensing data to assess the spatial and temporal variability of NO 2 concentrations in the Lithuanian coastal zone and adjacent marine areas. The analysis focuses on identifying spatial patterns of NO 2 concentration distribution, localized pollution hotspots, and their relationships with population distribution. Correlation analysis for the 2022–2024 period revealed a statistically significant negative relationship between NO 2 concentrations and distance from the coastline in inland areas, whereas no statistically significant relationship was observed offshore. NO 2 concentrations at 0 m and 50 m were strongly positively correlated across all spatial domains and seasons (r > 0.98, p < 0.001), indicating consistent vertical spatial patterns. Annual mean NO 2 concentrations were also strongly positively associated with population density (r = 0.81).