System to gauge role of pollutants in fog, visibility forecasts in Delhi-NCR

Currently, the system is giving predictions two days in advance, but the technology is being studied and required changes will be made in the coming weeks before the portal is made public, scientists said

The Indian Institute of Tropical Meteorology has developed an early warning and prediction system, which will for the first time take into account the role of pollution in causing foggy conditions and low visibility in Delhi-NCR during the winter season, scientists said on Thursday.

The fog prediction system, which has now been launched by IITM in collaboration with the UK Met office, on an experimental basis, will give out advance forecasts of fog and visibility status in the Indo-Gangetic region. (PTI File)

They said the new system will also enable agencies to avoid flight delays and cancellations, while making available forecasts for the public.

The fog prediction system, which has now been launched by IITM in collaboration with the United Kingdom’s Met office, on an experimental basis, will give out advance forecasts of fog and visibility status in the Indo-Gangetic Plains (IGP), while also outlining how aerosols impact foggy conditions and visibility.

Currently, the system makes predictions two days in advance, but the technology is being studied and changes will be made in the coming weeks before the portal is made public, scientists said.

“Under the project initiated by the Union ministry of earth science, we took a deep dive into understanding fog in Delhi nearly three to four years ago. Based on our knowledge and learning, we have launched the fog prediction system on a pilot basis. This will not only help agencies prepare for severe fog spells that Delhi sees in December and January, but also forecast these conditions make it available for public consumption,” said Sachin Ghude, a scientist at IITM Pune, who is also the lead for the government’s Winter Fog Experiment (WiFEX).

For example, for December 17, the fog forecast said the visibility in Delhi is likely to be above 2,000 metres in the morning hours and will consistently improve as the day progresses.

Gaurav Govardhan, a scientist at IITM, and a member of the team that developed the system, said aerosols or pollutants cause formation of fog droplets.

“The technology is the same as we use for general weather forecasting— just that this time, we are taking into account the impact of aerosols or pollutants on fog formation. Aerosols can help in the formation of fog droplets, which essentially means that more pollutants in the air the greater is the possibility of the formation of fog droplets. You don’t need very humid air for fog,” Govardhan said.