This study presents a year-bound assessment of ambient particulate matter (PM10, PM2.5, PM1.0), aerosol optical depth (AOD), and black carbon (BC) over Agra, a semi-arid region within the Indo-Gangetic Basin (IGB) and a major air-pollution hotspot. The study integrates ground-based measurements, satellite datasets, and advanced morphological characterization (FESEM-EDX) to evaluate seasonal and diurnal variations, meteorological influences, and aerosol composition. The annual mean concentrations of PM10 (160.3 mu g m- 3), PM2.5 (90.7 mu g m- 3), and PM1.0 (58.5 mu g m-3) exceeded Indian NAAQS limits, indicating chronic exposure risks. Winter (Dec-Feb) showed peak pollution due to low boundary layer heights, thermal inversions, and increased biomass combustion, while monsoon (Jul-Sep) had the lowest levels owing to wet scavenging. Post-monsoon BC spikes are aligned with crop residue burning, and diurnal BC peaks reflected traffic and domestic activities. Satellite-derived aerosol optical depth (AOD) correlated with BC (r approximate to 0.64), although MERRA-2 underestimated short-term high-AOD events. FESEM-EDX analysis revealed seasonal shifts: mineral dust and quartz dominated in summer; soil organics increased during monsoon; and soot, fly ash, and secondary aerosols (S, N) prevailed in winter. Temperature showed negative correlations with PM and BC (r = -0.40 to -0.46), while high humidity enhanced aerosol growth in cold seasons. Wind speed negatively influenced pollutant levels, and wind rose analysis identified seasonal transport patterns. The study underscores the need for season-specific mitigation strategies and improved monitoring to identify and address both local and regional sources. Targeted interventions, such as controlling wintertime combustion, reducing post-monsoon biomass burning, and enhancing early-warning systems are recommended to reduce exposure. Strengthening satellite - ground integration will further support evidence-based air quality management in IGB cities.