Indian Study Links La Nina Events to Air Quality Anomalies

• 20 Feb 2024

A recent study by Indian researchers unveils a link between La Nina events and air quality fluctuations in India.

Key Points

• Pollution in Winter Months: During October to January, northern Indian cities witness high PM2.5 levels due to various meteorological factors.
• These factors trap pollutants and transport them from regions like Punjab and Haryana to cities like Delhi.
• Deviation in Winter 2022: Winter 2022 saw a deviation from the norm, with northern cities experiencing cleaner air while western and southern cities faced worse air quality.
• PM2.5 concentrations dropped in northern cities like Delhi but rose in cities like Mumbai and Bengaluru.
• Impact of La Nina: The abnormal wind patterns during Winter 2022 were influenced by La Nina, a phenomenon persisting for an extended period.
• The wind direction shifted, causing pollutants from northern states to bypass Delhi and reach southern regions like Mumbai.
• Anomalies in wind circulation near Mumbai also contributed to higher pollution levels.
• Climate Change Influence: The prolonged La Nina event demonstrated a strong correlation with changes in wind patterns over India, affecting air quality.
• The study suggests an accumulative effect of strong La Nina events on air circulation and pollution.
• Uncertainties and Local Factors: While La Nina played a significant role, local meteorological conditions unrelated to La Nina also affected air quality trends.