MUMBAI: Pollution levels in the city slipped back into the 'poor' category as minimum temperatures dipped on Tuesday. The chill returned to the city after a long gap as the minimum temperature dropped to 15 degrees Celsius on Tuesday morning. On January 6 this year, minimum temperature recorded in Santacruz dropped to 15.2 degrees Celsius.
On January 19, minimum temperature recorded at Santacruz was 15 degrees Celsius which was 1.7 degrees below normal, while at Colaba it was 19.8 degrees Celsius which was 0.9 degree below normal. V K Rajeev from IMD Mumbai attributed the chill to the wind pattern. "Earlier, the winds were easterly. However, the prevailing wind pattern from northerly to north westerly has led temperatures to drop," said Rajeev. Weather officials said minimum temperatures may drop further. The lowest temperature recorded this month was 13.2 degrees Celsius at Santacruz on January 3.
Humidity levels in the city remained very low on Tuesday, recorded at 57% in Colaba and 26% in Santacruz. Maximum temperatures meanwhile continued to remain below 30 degrees Celsius. The maximum temperatures recorded on Tuesday at Colaba were 27.8 degrees Celsius and at Santacruz it was 28.4 degrees Celsius.
The dip in temperatures on Tuesday were accompanied by increased air pollution. According to real time data made available by System of Air Quality and Weather Forecasting and Research (SAFAR), the Air Quality Index on Tuesday evening was 242, up from 212 the previous day. An AQI between 201 and 300 is considered 'poor', which means people with heart or lung disease, older adults and children, should reduce prolonged or heavy exertion.
AQI uses the 24-hour averages of pollutants, including sulphur dioxide, nitrogen oxide, carbon monoxide, ozone (O3) and particulate matter. In the last week of December as temperatures dipped to record lows in a few years, the city's AQI was in the very poor category, which is above 300.
Experts said there was a direct correlation between temperatures and the AQI. "Towards the end of December and in the first two weeks of January, temperatures were low and winds were calm. Last week, the winds picked up speed so the pollutants were being carried away. However, in just a day or two the temperatures dropped again, raising the pollution levels. The levels are still better compared to the start of the year," said GufranBeig, scientist at Indian Institute of Tropical Meteorology (IITM), Pune and project director, SAFAR. With an AQI of 305 and 300, pollution levels on December 31 and January 1 were close to that on Diwali days.
