A multi-sensor satellite assessment of air quality during the 2026 Middle East Conflict across nine regional countries.

The 2026 Middle East conflict (28 February - 7 April 2026) imposed a 39-day perturbation on regional atmospheric composition across nine Middle Eastern countries (∼217 million people). We used a dual-baseline framework comparing the conflict period against both a 14-month annual baseline and a seasonally matched baseline one year earlier to separate conflict-period signals from routine seasonal variability, while integrating Sentinel-5P TROPOMI, Aura/OMI, MODIS MAIAC, CAMS, ERA5, and VIIRS data to quantify country-level changes in NO2, SO2, CO, CH4, and AOD. Domain-mean column anomalies on the annual baseline were -15.1% for NO2, -45.6% for SO2, -8.6% for CO, and -19.6% for AOD; CH4 showed no change above retrieval noise (+0.37%). This hierarchy tracks the atmospheric residence time of each species, a pattern more consistent with an emission-driven signal than a purely meteorological one, though meteorological influence cannot be fully excluded from the satellite record alone. NO2 and SO2 cold spots clustered over the south-western Iranian oilfields, the Kuwaiti oil-field corridor, and the Qatari North Field, coinciding with the regional ranking of hydrocarbon exports. The Iranian meridional wind reversed sign between baseline and conflict periods, weakening rather than enhancing transport from Iranian sources toward the western Gulf. The annualised Monte Carlo-derived NO2 burden was -7,849 cases (95% CI: -35,641 to +13,551), with Iran and Iraq contributing 99% of the estimate; the wide interval, which crosses zero, means this estimate cannot support a confident public-health conclusion and is reported as an exploratory upper-bound context rather than a definitive burden. PM2.5 burden estimates remain indeterminate because of inseparable dust and anthropogenic aerosol mixing over the Arabian Peninsula at CAMS operational resolution. Taken together, the results are consistent with reduced hydrocarbon-sector emissions during the conflict period, though they should not be interpreted as evidence of a public-health benefit.