Chandigarh, Oct. 7 -- The city's air quality has, for the first time this season, slipped to the moderate level (102) after remaining in the good to satisfactory category for at least a week (see box). The rise in pollution, India Meteorological Department (IMD) officials say, is due to the dropping temperatures and weaker winds. Explaining the science behind it, an IMD official said temperature inversion - an atmospheric condition where a layer of warm air sits on top of a layer of cooler air near the Earth's surface - is a big factor as it traps pollutants closer to the ground An anticyclonic movement prevalent over the region, which keeps winds from blowing, is also reducing the dispersion of pollutants, officials added. The situation will only worsen around November, when the temperatures drop more, and stubble burning and cracker bursting will add to the pollution levels, the officials warned. According to the Met officials, the relatively early withdrawal of monsoon, declared on September 23, is one of the reasons for the deterioration beginning in early October this year. Residents can expect relief from the rising mercury, humidity and pollution levels due to a fresh Western Disturbance which is likely to bring light rains to the city. The maximum temperature increased slightly from 34.7degC on Monday to 34.8degC on Tuesday, two degrees above normal. The minimum rose from 23degC on Monday to 24.6degC on Tuesday, four degrees above normal. Over the next three days, the maximum will remain between 32degC and 33degC while the minimum will remain between 23degC and 24degC....