HKH scientists plan to investigate the problem of fog in the Indo-Gangetic Plain


On 2-3 December 2014, about 20 scientists from five countries – Pakistan, India, Bangladesh, Bhutan and Nepal – gathered at the ICIMOD headquarters in Kathmandu to develop a research plan for studying the science, impacts and policy aspects of the fog that persists in the Indo-Gangetic Plain (IGP) during winter season. 

Since the winter of 1998-99, researchers have documented widespread fog that occurred over a 1,500 km distance in north-eastern Pakistan, India and Bangladesh. They speculated that the high sulfate content in the droplets could possibly be linked to the aqueous phase oxidation due to emission of coal-fired power plants situated upwind. Indian scientists have also noted the fog that occurs in Delhi during the post-monsoon (October-November) and winter seasons (December-February), with the highest density fog observed in December and January. During this period temperatures can go down below 10 degrees Celsius, which could be linked to human activities during stagnate high-pressure synoptic condition.

Winter fog is a natural meteorological phenomenon caused by water droplets suspended in the air, and is a common occurrence in this region during winter. However, in the last two decades, dense fog has been seen to stay for many days without a break, and this is establishing itself as a new phenomenon.  This causes frequent disruptions of road, air and railway traffic, leading to accidents. The dense and persistent fog also leads to winter crop loss and accompanying cold waves, resulting in various illnesses and deaths.

During the meeting, it was decided to conduct a pilot study in the five countries in 2014-15, and a full-scale study in the winter of 2015-16. Scientists from the National University of Science and Technology (NUST) and the Institute of Space Technology in Pakistan and colleagues from the Indian Institute of Technology (IIT), the Indian Institute of Tropical Meteorology (IITM), the Indian Institute of Science Education and Research (IISER), and Dibrugarh University are actively collecting ground observation and conducting satellite data analysis in their respective institutions. They are also using the meteorological models to understand the atmospheric processes. Scientists from Dhaka University and North-South University in Bangladesh, and Sherubtse University in Bhutan are studying the scientific aspects of the fog and assessing its impacts. The IT team at ICIMOD is also developing a Winter Fog App, which will allow the public to feed their own observations into ICIMOD’s central system. These observations will be complied and used in the research to help identify appropriate mitigation measures.