The metrological limits of prominent pollutants on National Ambient Air Quality Index (NAAQI) have measured under their prescribed limits on Wednesday. In December, this is the first time when the concentration values were recorded under the limits. Environmentalists said wind speed and relative humidity are the factors for low values of Suspended Particulate Matters (SPMs) on Air Quality Index (AQI). City’s Mandir Marg area recorded lowest values of PM 2.5 at 59µg/m3.
From “very poor” to “moderate”, the NAAQI has updated its air quality status and forecasting the same for next three days. According to India Metrological Department (IMD), wind speed was 14KM/h recorded. “ Currently, Delhi’s climate conditions are favorable, the high wind speed settle down the SPMs, Secondly, Delhi is not witnessing fog which results zero thermal inversion process,” said an Environmentalist.
As per US Embassy real time air data, values of PM 10 and 2.5 in per cubic micro gram were recorded at 117 and 142 while other pollutants (Ozone, Nitrate of Oxides) values were recorded at 3 and 11. Importantly, value of carbon monoxide was recorded at Zero at all monitoring stations of Delhi-NCR region.
The Capital’s minimum temperature settled at 11.1 degrees Celsius, three notches above the season’s average.
The maximum temperature was recorded at 25.3 degrees Celsius, four notches above the normal, a Met department official said.
Poor visibility due to fog delayed the movement of 32 trains, while five others were rescheduled, railways officials said. The visibility was recorded at 2,000 metres at 5.30 am and 1,500 metres at 8.30 am at Safdarjung, said the MeT official, adding there was mist in the morning.
Wind was blowing at 8 knots (15 km/hr) in the morning, resulting in normal visibility, he said. At Palam, visibility was 1,500 metres at 5.30 am which dropped to 800 metres at 8.30 am. It improved to 1,700 metres at 11.30 AM. The humidity oscillated between 77 and 30 per cent.