Foggy Welcome To 2024 – OpEd
Biting cold gripped several places of Punjab and as temperature dropped to minus Celsius in several parts of Punjab, a dense layer of fog has engulfed the city, causing in-conveninance for commuters. The India Meteorological Department (IMD) warns of persistent dense to very dense fog in Northwest and Central India over the next two to three days. Specific regions, including Punjab, Haryana, Delhi, and Uttar Pradesh, are expected to experience these conditions. Recent disruptions in air and rail travel highlight the impact of dense fog
Seems like this New Year is going to be foggy and rainy at some places in India! The India Meteorological Department (IMD) has, the country’s nodal weather agency, indicated that dense to very dense fog is expected to persist over Northwest and parts of Central India in the coming days.
According to the IMD, dense fog conditions are anticipated during the early hours in Odisha and Uttarakhand in December. Haryana, Chandigarh, Delhi, and Uttar Pradesh will also see heavy fog on December 30th and 31st, and over Assam, Meghalaya, Nagaland, Manipur, Mizoram, and Tripura from December 27th to 31st. The weathermen have also issued a ‘red alert’ in view of the dense fog cover and the low mercury levels for Friday. An ‘orange alert’ has been sounded for Saturday (December 30) and Sunday (December 31) and a ‘yellow alert’ for New Year’s Day as January 1, 2024, may once again see dense to very dense fog, the regional unit of IMD in Chandigarh.
In Jammu and Kashmir, dry weather, along with moderate to dense fog, will persist over Central Kashmir, Pulwama, and Baramulla until December 31st. The forecast also mentions light rain and snow at some places, accompanied by cloudy skies in January. On December 26th, dense fog reduced visibility in various areas, causing delays for about 30 flights, including international ones, at the Delhi airport, and also caused problem to 14 trains. Punjab and Haryana also experienced a dense fog on Tuesday. In Punjab, several cities reported of heavy fog including Amritsar and Ludhiana.
As per the weather department, a new Western Disturbance is expected to influence Northwest India from December 30th. Under its influence, light isolated rainfall is likely over Northwest and adjoining Central India from December 30th to January 2nd, 2024.
As per IMD, the state will witness very dense fog during the next 24 hours. The extreme weather activity will continue in the state for the next 4-5 days. Fog reduced visibility at several places in the morning. Very dense fog was reported from Amritsar, Ludhiana, Patiala, Halwara, Bathinda and Faridkot in Punjab. IMD, has advised people to avoid travel during the morning and evening hours as visibility in some districts of the state will drop to zero metres.
Fog is a cloud that touches the ground. Fog can be thin or thick, meaning people have difficulty seeing through it. In some conditions, fog can be so thick that it makes it hard to drive safely because it obscures the road and other cars. In other words, a cloudlike mass or layer of minute water droplets or ice crystals near the surface of the earth, appreciably reducing visibility Just like clouds, fog forms when the temperature equals the dew point temperature, and sufficient condensation nuclei are available for the water droplets to condense onto.
Fog is categorised as “very dense” when the visibility goes below 50 metres. On the other hand, if the visibility is between 51 to 200 metres, it is considered “dense” fog and “moderate” fog prevails when the visibility is between 201 and 500 meters. Dance fog would severely affect air and train travel.
Fog is made up of molecules of water vapour, suspended in the air as tiny droplets of water but lingering close to the surface. Essentially, fog is just cloud that touches Earth’s surface and it forms the same way that clouds do. High humidity is a major contributing factor to the formation of fog, and depending on the percentage (as well as temperature), fog can appear and disappear very suddenly.
Water in the vapour state is transparent and invisible. The warmer the air, the more kinetic energy it has, and so the more water molecules it can keep jostling around as vapour.
If warm air containing lots of water vapour cools down suddenly, the water molecules slow down too much and are unable to stay in vapour form. Instead, they clump together into tiny droplets of liquid water. The droplets are still small enough to hang suspended in the air currents, but now they appear opaque because light reflects off the air/water interface.
Radiation fog
Radiation fog forms over land on calm, clear nights when heat absorbed by the Earth’s surface during the day is radiated into the air. As the heat escapes upwards, air close to the surface is cooled until it reaches saturation.
Cold air holds less water vapour than warm air, and the water vapour condenses into fog. Radiation fog will usually ‘burn off’ as the ground begins to warm again, but during winter months it can persist all day.
Radiation fog is also known as shallow fog or ground fog when it occurs in a narrow enough layer, situated below average eye-level on land (around 2m), or below around 10m at sea.
Valley fog
Valley fog usually forms in the lowest parts of a valley as cold, dense air settles and condenses, forming fog. It’s confined by local topography, such as hills or mountains, and can persist for several days.
Advection fog
Advection fog forms when horizontal winds push warm, moist, air over a cool surface, where it condenses into fog. It’s common at sea, where warm, tropical air moves over cooler water. Advection fog can cover wide areas, and the Golden Gate Bridge in San Francisco Bay is often shrouded in advection fog.
Sea fog, a type of advection fog, can occur when warm, wet, air rolls off the land and onto the colder sea, or when a warm weather front hits a cold ocean current. In the UK, the north-east coast is very prone to sea fog because of the cold waters of the North Sea.
Upslope fog
Upslope fog is a type of hill fog and forms when the wind blows moist air up a slope, hill, or mountain, which cools as it rises. As it cools, the moisture condenses, and fog is formed as it continues to drift up the slope.
Evaporation fog
Evaporation fog is similar to advection fog, and forms as cold air passes over moist land or warm water. When the warmer water evaporates into the low bands of air, it warms the air and causes it to rise. As this warm, moist air rises, it mixes with the colder air until its humidity reaches 100 per cent, and fog is formed. You’ll often see evaporation fog over lakes, ponds and even outdoor swimming pools.
Winter fog can be bad for your health as dense fog contains particulate matter and other pollutants and in case exposed it gets lodged in the lungs, clogging them and decreasing their functional capacity which increases episodes of wheezing, coughing and shortness of breath. The fog conditions may tend to irritate the membranes of the eye causing various infections leading to redness or swelling of the eye.
A thick blanket of fog enveloped several parts of Punjab and Haryana on Tuesday morning as cold weather conditions continued to prevail in the two States. Fog reduced visibility at several places in the morning, according to Meteorological Department. Very dense fog was reported from Amritsar, Ludhiana, Patiala, Halwara, Bathinda and Faridkot in Punjab and Karnal, Hisar, Ambala and Sirsa in Haryana.
Meanwhile, in Haryana, Hisar recorded a minimum temperature of 7 degrees Celsius while Rohtak’s minimum settled at 8.4 degrees Celsius. Fatehabad registered a minimum temperature of 6.9 degrees Celsius.
In Punjab, Pathankot, Bathinda, Faridkot, Gurdaspur, Amritsar, Ludhiana and Patiala experienced a cold night recording respective minimum temperatures of 6.5 degrees Celsius, 6.4 degrees Celsius, 7.5 degrees Celsius, 7 degrees Celsius, 8.2 degrees Celsius, 7.2 degrees Celsius and 8.6 degrees Celsius.
Chandigarh, the common capital of the two states, recorded a low of 8 degrees Celsius.
IMD, has advised people to avoid travel during the morning and evening hours as visibility in some districts of the state will drop to zero metres.
