The prevalence of dense winter fog has become a regular phenomenon over the past many years and the duration of this condition is constantly increasing. The north Punjab in Pakistan, especially Lahore, is one of the worst affected areas in the country, with milder forms of fog engulfing other parts including Sheikhupura, Faisalabad and Multan. It was observed that there were 11 days of dense fog during the winters of 2012-2013 as compared to 17 days in 2014-2105. Last year, the dense fog was also seen during the month of February If the trend continues, the spell might be even longer this time.
The fog is so dense during these days that normal life is disturbed to a great extent and those trying to cope with the condition become highly vulnerable. As per data compiled by researchers based in the National University of Science and Technology (NUST) and the Institute of Space Technology (IST) — both based in Islamabad, — the 2014-15 winter fog adversely affected economic and social aspects of everyday life. It claimed more than 76 lives were lost and 450 injuries were reported in roadside accidents due to low visibility on highways as well as on roads in Lahore, Rahim Yar Khan, Gujranwala, Gujrat, Narowal, Multan, Depalpur, Kasur, Jhang and Faisalabad.
The data shows power outages were also experienced across the affected areas. According to Multan Electric Power Company (MEPC), a large number of power transformers tripped due to heavy fog on December 15 and December 16 last year. On December 24, more than 60 feeders of Lahore Electricity Supply Company (LESCO) tripped during the midnight due to adverse foggy weather causing power outage in many areas of the city. The heavy losses to crops and disruptions in flights and transportation of goods from one city to the other are other adverse impacts.
According to a flight operation report, 41 flights were affected in 2012, 38 in 2013 and 43 in 2014 due to dense foggy conditions at Lahore airport. This year a modern Instrumental Landing System CAT III-B has been installed at this airport to facilitate aircraft landing even in 50 meter visibility but the results have not been satisfactory so far.
The phenomenon is not only restricted to Punjab; in fact it can be observed across the Indo-Gangetic Plains stretching from Pakistan across northern India and southern Nepal and Bhutan to Bangladesh. Winter in the Hindukush Himalayas usually lasts from December to February. During this time many low-land areas and valleys experience short durations of morning fog. Since the 1990s, big changes have been observed, with periods of dense fog and low stratus clouds stretching across vast regions continuously for weeks.
No doubt there have been pilot studies and mappings of areas most affected by this dense winter fog, but what is lacking is the on-ground research, collection of samples, identification of reasons causing this fog and a plan to help tackle the issue.
The good news is that a recent initiative launched with the support of the International Centre for Integrated Mountain Development (ICIMOD) — a regional intergovernmental learning and knowledge sharing centre serving the eight regional member countries of the Hindukush Himalayas — brings experts from these states together to carry out the required research. Teams of experts in different countries will collaborate with leading educational institutes to carry out research and use sophisticated equipment to collect samples. In Pakistan, NUST and ICT are partnering with institutions like Lahore University of Management Science (LUMS), Lahore University of Engineering and Technology (UET), Lahore University of Agricultural Faisalabad (UAF) in this regard.
Dr Muhammad Faheem Khokhar, Assistant Professor, Institute of Environmental Sciences and Engineering, who is involved in the said project, explains fog is an atmospheric phenomenon and visible mass consisting of water droplets suspended in the air or near the earth’s surface.
It can be considered a type of low-lying cloud, and is heavily influenced by nearby bodies of water, topography, pollutants in air and other conditions. Fog and clouds are formed under the same phenomenon and in case of dense fog the vapours that should have risen to form clouds are trapped within different layers close to the earth.
The said project, Khokhar says, aims to evaluate the sources of the dense winter fog in the affected areas and dynamics that are driving it to be dense and persistent. He tells TNS they will monitor the atmospheric at selected sites over the whole two-month winter period, will collect fog water samples and send these to Nepal. “This will let us know what type of water — industrial, irrigation or drinking — is contributing to fog and what type of particulate matter is present that serves as the condensation nuclei.”
Replying to a query, he says there is a strong possibility that smoke also leads to this condition and they have found presence of smoke/absorbing aerosols over dense fog areas through satellite observations. He shares a research finding in which they found that Lahore’s air was more polluted during the night and less during the day. “After a deeper study, it was found that industries use safe fuel during the day out of fear of action by regulators, but at night they burn all types of combustible material including tyres and rubber. They feel safe as the regulators are off from work during these times,” he adds.
Dr Farrukh Ahmed Chishti, Head of Department (Space Science) at the Institute of Space Technology (IST), clarifies that the fog in question is called radiation fog. It usually occurs in the winters when the angle of sun’s elevation is low and it is there for lesser hours. He says the cooling of land by thermal radiation from earth cools the air close to the surface. Due to this, condensation occurs and the moisture present in the air causes fog. This fog usually disappears after the sun rises and makes the ground warm, he adds.
Chishti tells TNS that the first phase of the study is about identifying sources and causes, and mitigation plan will definitely be based on the results. As it is a trans-boundary initiative, he says, it is quite likely that the countries of the region will come up with a joint plan of action.
“Though we are struggling to find answers to a long list of scientific questions, we are also studying the social impact of this phenomenon and the changes in people’s lives. The human vulnerabilities are enough ground to justify the need of this study,” he concludes.
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