‘Zero sunlight’ hours recorded in Ludhiana since November 5 as farm fires continue to rage
Sunshine hours are used as an indicator by weather experts to record the duration for which a particular area receives clear sunshine as opposed to daylight hours, which is the duration between sunrise and sunset.
As the city has been shrouded by a thick blanket of smog it hasn’t seen zero sunshine hours since 5 November, according to the data collected by Punjab Agricultural University (PAU).
Sunshine hours are used as an indicator by weather experts to record the duration for which a particular area receives clear sunshine as opposed to daylight hours, which is the duration between sunrise and sunset.
“There is thick blanket of smog that covers the city and the region due which block the sunlight from coming down to the ground,” said Dr Sompal Singh, Department of Agricultural Meteorology, Punjab Agricultural University (PAU).
Smog, he explained was a mixture of fog and smoke and dust. “Humidity is high but as smoke and pollution rise, it results into this smog,” he added.
The reason for increased pollution, according to weather experts, was the decreasing temperature and calm air conditions.
“As temperature cools down the air along the ground doesn’t get hot and can’t rise, which could take the pollution up and clear the air on the ground. Also if there was wind speed above 6 kmph the polluted air could move out but the air speed in the city over the last two weeks has been around and less than 2 kmph, which is called calm condition,” said Head of Department, Dr Pavneet Kingra.
Dr Sompal said that paddy straw burning was the leading cause behind the pollution and as long as it continued the city may not be able to get any sunshine hours.
“The window for wheat sowing is between 15 October to 15 November. Most of paddy is harvested and the farmers are clearing their fields to make way for wheat sowing. This may end by November end. We can expect clear sunshine as soon as that happens,” he said.