The atmospheric-surface Nexus in a hyper-arid coastal metropolis: Compound heat and pollution risk across Doha's urban morphologies (2018–2025)

Abstract

Rapid urbanization in hyper-arid coastal cities can generate compound environmental risks through interacting surface heat, biometeorological stress, and atmospheric pollution. This study characterizes the Atmospheric–Surface Nexus in Doha, Qatar, by integrating seven satellite-derived environmental variables across six morphologically distinct urban zones in 2018 and 2025. Land Surface Temperature (LST), Approximate Wet-Bulb Globe Temperature (AWBGT; used as an uncalibrated biometeorological proxy), tropospheric NO₂, SO₂ and CO, Aerosol Optical Depth (AOD), and Normalized Difference Vegetation Index (NDVI) were evaluated using a multi-tier statistical framework incorporating non-parametric tests, correlation analysis, and multivariate regression with multicollinearity and residual spatial-dependence diagnostics. Results show that thermal change was strongly season-dependent rather than uniformly increasing, with the largest upward shift occurring during March–May. This shift was particularly evident in rapidly developing peri-urban areas, indicating an encroachment of elevated heat conditions into the climatologically mild part of the year. Multivariate models identified urban morphology and NO₂ among the strongest statistical predictors of AWBGT, while the NO₂–LST Spearman correlation increased from ρ = +0.103 in 2018 to +0.493 in 2025, suggesting stronger statistical coupling between atmospheric pollution and surface thermal conditions. The analysis also reveals a Green–Blue Paradox. Vegetation and water features can reduce LST while their association with moisture may limit corresponding reductions in humidity-sensitive AWBGT under coastal conditions. Although the absence of in-situ meteorological calibration limits interpretation of absolute biometeorological risk, the findings identify morphology-specific and seasonally shifting patterns of compound heat exposure and provide a transferable framework for urban heat-risk assessment in rapidly urbanizing hyper-arid coastal cities.