Air Quality & Pollution Forecast — India

What's on the Map

• PM2.5 — fine particulate matter (µg/m³), the primary health-relevant pollutant metric used by AQI systems worldwide.
• PM10 — coarse particulate matter (µg/m³), including dust and larger combustion particles.
• AOD 550nm — total column aerosol optical depth at the 550 nanometre band, a unitless measure of how much aerosol is scattering or absorbing light through the full atmospheric column.
• Dust AOD 550nm — the dust-specific component of AOD, isolating mineral dust transport (e.g. pre-monsoon dust storms over northwest India) from smoke, sulphate and other aerosol types.
• Visibility (IGP / AOD-based) and Visibility (PM / Koschmeider) — two independent visibility estimates in metres, described below.

How Visibility Is Estimated

VayuMet runs two independent, experimental formulas to translate aerosol loading into a visibility estimate, both incorporating a per-pixel humidity correction f(RH) derived from GFS 2 m temperature and dew point:

• AOD-based IGP formula: V = 4 × H_eff / (AOD × f(RH)) — integrates column AOD over an effective mixing height (default 1,000 m).
• PM2.5 Koschmeider formula: derives visibility from near-surface PM2.5 concentration and the same humidity correction.

Both methods are experimental and intended for spatial pattern guidance (e.g. identifying haze corridors along the Indo-Gangetic Plain), not as a substitute for official METAR/TAF visibility reports — use the Aviation Dashboard for operational aviation visibility.

Data Source

Who Uses This

Air quality and visibility maps support flight planning where haze or dust reduces visibility below VFR minimums, public health advisories during high-pollution episodes (e.g. winter inversion events over the Indo-Gangetic Plain), and event or logistics planning around dust storms and smoke transport.