Challenges in Early Warning of the Persistent and Widespread Winter Fog over the Indo- Gangetic Plains: A Satellite Perspective - Reducing Disaster: Early Warning Systems for Climate Change - page 51

Fig. 3.1 Widespread winter fog blanketing the Indo-Gangetic Plains over Pakistan, India, Nepal,
and Bangladesh, captured by NASA's MODIS instrument aboard Terra satellite on 7 January 2011
which the diesel-run types constitute a signifi cant percentage. Together with the
pollution from industrialization and urbanization, biofuel cooking is common
among the rural population, which also contributes to the net air pollution. Frequent
winter cold waves lead to dramatic dips in temperatures with lowest annual tem-
peratures recorded during this time of the year. To combat the cold, the underprivi-
leged keep themselves warm by burning wood and other old/traditional alternatives
causing enhanced aerosol emission in the atmosphere. The impact of this tremen-
dous conglomeration of aerosols is felt the most every year during winter period
when thick and dense haze engulfs the entire IGP.
Overall, the valley-type topography of the IGP bounded by the Himalayas, cold
waves with moist air, and the resident aerosols are among the most important ingre-
dients for the formation of winter fog. The dense haze and fog also reduce solar
insolation from warming the land surface which further keeps the temperatures low,
in turn providing a positive feedback to the persistence of foggy and cold conditions.
Moreover, the winter fog has been around in the past several decades, and may
potentially intensify in future given the worsening air quality. Despite its known
consequences on the social and fi nancial sectors, little attention has been given to
the increasing fog formation that blankets the entire IGP during winter season.
In this chapter, satellite observations are used to better understand the widespread
nature of the winter fog/haze over the IGP from Moderate Imaging Spectroradiometer