As the Delhi airport braces for another season of fog, it has started receiving help from scientists at the Pune-based Indian Institute of Tropical Meteorology (IITM) to predict visibility levels at least a day in advance.
The airport currently has advance visibility information of about four-five hours. A new forecast model developed by IITM scientists in the last couple of years has enabled scientists to predict visibility levels between 12-24 hours in advance.
IITM started sharing this information with the Delhi airport, on an experimental basis, on November 30. Sachin Ghude, one of the researchers on the Winter Fog Experiment (WIFEX) project that has developed the new forecast model, said that so far, the predictions have matched with the observed data. The visibility has not gone below 400-500 metres in the last few days.
A weather forecaster at the Delhi airport said they are in the process of “evaluating IITM’s improved model” of fog forecasting. He said a major fog event at the airport is unlikely before December 10. In the wake of major disruptions in flight schedules caused by fog in the last few years, scientists have been working on developing a reliable fog forecasting technology.
Last year, they had concentrated on studying the science behind fog formation. Using that knowledge, this year they developed a new, improved forecast model, which can predict fog and the resultant visibility levels a day in advance. The results of their study were recently published in the Current Science journal. “The aim, eventually, is to improve capability in fog prediction. Extensive sets of comprehensive ground-based instrumentation, including remote sensing platforms, were deployed at IGIA, New Delhi to measure micrometeorological conditions, radiation, fog droplet and aerosol microphysics, aerosol optical properties, and aerosol and fog water chemistry to describe the complete environmental conditions in which fog develops,” Ghude said.
These measurements helped scientists understand some key questions on fog formation and dispersion. When assimilated into models, it will further help in improving the prediction skills, Ghude said. WIFEX was conducted on a pilot mode at IGIA, and will be repeated during the next three to four winter seasons. This data will lead to a better understanding of the fog life cycle and help develop a suitable forecasting system for airports, scientists said.