Smoke AOD (550nm)

Smoke Aerosol Optical Depth (Smoke AOD) quantifies atmospheric light extinction caused by carbonaceous aerosols from biomass burning, wildfires, agricultural fires, and anthropogenic combustion sources, providing photographers with critical advance warning of visibility degradation from smoke plumes. This metric specifically tracks fine-mode aerosols (particle diameter less than 1 micrometer) composed of black carbon (elemental carbon soot) and organic carbon compounds produced during incomplete combustion. Unlike coarse mineral dust which produces warm-toned haze, smoke particles exhibit neutral to brownish-grey coloration with distinctive optical characteristics: strong light absorption by black carbon combined with scattering by organic carbon creates thick, opaque atmospheric haze that severely reduces visibility and photographic quality even at moderate concentrations.

Smoke AOD values below 0.03 indicate clean air with negligible smoke impact, 0.03-0.08 produces light smoke haze noticeable as slightly reduced clarity and muted colors but often still acceptable for photography, 0.08-0.20 creates obvious smoke haze with significantly degraded visibility and washed-out colors making most landscape photography challenging, 0.20-0.50 indicates dense smoke reducing visibility to a few kilometers with heavily muted colors and milky-white or grey-brown skies, while values exceeding 0.50 represent extreme smoke events (major wildfire plumes, severe agricultural burning episodes) that create apocalyptic orange/red lighting conditions with near-zero visibility for anything beyond close subjects. Wildfire smoke is the primary driver of high Smoke AOD in most regions: during active fire seasons (summer-autumn in North America, dry seasons in Australia, Southeast Asian burning season February-April), smoke plumes can travel thousands of kilometers from source fires, affecting photography across entire continents. The 2023 Canadian wildfire season, for example, produced Smoke AOD values exceeding 1.0 across the U.S. Northeast, creating orange skies and rendering outdoor photography nearly impossible for weeks.

PhotoWeather's integration of CAMS smoke forecasts helps photographers anticipate and avoid smoke plumes by providing 5-day predictions of Smoke AOD at your specific location. For astrophotographers, Smoke AOD below 0.05 is essential to avoid significant light extinction; for landscape photographers, values below 0.08 maintain acceptable clarity while values above 0.15 generally make high-quality work impossible. Some photographers embrace moderate smoke (0.15-0.30) during sunrise/sunset for dramatic red/orange sun disks and apocalyptic moods, though such conditions remain controversial and uncomfortable to work in.