2 hrs ago

Western Disturbances May Forecast North India’s Winter Pollution

Western disturbances are storm systems that travel from the Mediterranean region toward South Asia.

They can bring rain and stronger air movement to northern India.

This helps clear tiny pollution particles called PM2.5 from the air.

Winters with more of these storms usually have less pollution.

Winters with fewer storms can have longer and more serious pollution.

Researchers found that these storms may explain about 70% of the yearly differences in winter pollution.

Ocean temperatures during autumn may help scientists predict how often the storms will arrive.

This could give officials about a season to prepare.

The researchers said forecasts should support, not replace, efforts to reduce emissions.

Key facts

Pollution variation explained: About 70% of year-to-year variation in winter PM2.5 pollution across northern India may be linked to western disturbances.
Storm origin: Western disturbances originate in the Mediterranean region and move eastward toward South Asia.
Pollution-clearing mechanisms: Enhanced ventilation and precipitation help remove PM2.5 from the atmosphere.
Forecast timing: Disturbance frequency and overall winter pollution severity may be estimated about a season in advance.
Relevant autumn signal: Ocean-temperature patterns observed during the preceding autumn are linked to disturbance frequency.
Other pollution factors: Vehicle emissions, stubble burning in Punjab, Haryana and Uttar Pradesh, and weather that traps pollutants near the ground contribute to winter pollution.
Potential uses: Authorities could coordinate responses, strengthen enforcement and prepare businesses and communities for possible restrictions before severe pollution periods.

rediff.com · 11 hrs ago