Pollution spikes as mercury hits new lowUpdated: Dec 04, 2019 20:45 IST
Gurugram Air quality in the city deteriorated on Wednesday, but continued to remain in the ‘poor’ category, as per Central Pollution Control Board’s (CPCB) air quality index (AQI). The city recorded an AQI reading of 279 on Wednesday, down from 246 (‘poor’) recorded on Tuesday, as per the CPCB’s 4pm bulletin.
Meanwhile, the minimum temperature dropped to 7.8 degrees Celsius on Wednesday, the season’s lowest so far, according to the India Meteorological Department (IMD), a drop from Tuesday’s minimum temperature of 9 degrees Celsius. The minimum temperature on Monday was 8 degrees Celsius.
Experts attributed the rise in pollution levels in the city to the fall in minimum temperature and decreased wind speeds. With similar meteorological conditions likely on Thursday as well, the pollution is expected to spike and air quality is predicted to be in the upper-end of the ‘poor’ category or the lower-end of the ‘very poor’ category, as per the CPCB.
“Whenever the minimum temperature falls to below 8 degrees Celsius, thermal inversion is stronger, leading to high pollution levels, particularly in the morning,” said Sachin Panwar, an air quality expert.
Thermal inversion occurs when a layer of warm air settles over a layer of cooler air that lies near the ground. The warm air holds down the cool air and prevents pollutants from scattering.
Wind speed on Wednesday was around 6kmph, said experts, which accentuated the pollution. Wind speed is likely to be low on Thursday too, as per the CPCB’s prediction. Air quality, on most days this week, is likely to be in the ‘poor’ category as per the prediction.
However, air quality could improve in the second week of December as light rain and high-speed winds are expected due to a western disturbance, said experts. The second week of December is also expected to see dense fog in the mornings, with the minimum temperature settling around 6 degrees Celsius, according to the IMD.
The maximum temperature on Wednesday was recorded at 23.5 degrees Celsius, also down from Tuesday’s 24 degrees Celsius, according to IMD data. The maximum temperature is expected to drop to 21 degrees Celsius early next week, officials said.