When tiny water droplets are suspended in the air, near or at the surface of earth, we experience a fog. It is essentially a cloud of water droplets that reduces horizontal visibility less than 1 km, study confirms.
Though, they are less the same, fog and cloud can be differentiated due to the place of hanging in that clouds hangs up in the sky while fog hangs near the earth surface. And, that is why most people would agree that foggy weather is not the most appealing of all weather conditions. It can be pretty restrictive especially if you are trying to get from one place to another.
Consequently, scientists have been able to categorize fog into various groups namely; stemming fog, radiation fog, ice fog, hail and sea fog, freezing fog, advection fog, evaporation fog to mention but a few.
Depending on type and formation, fog can be formed when there is a difference in temperature between two air masses and mostly when the cold air mass is trapped below a warmer air mass and relative humidity (i.e dampness of air in the atmosphere) is slightly less than or equal to a hundred per cent ( ≤100%). (Excerpt from Jacobson’s book: Fundamentals of Atmospheric Modeling).
Cotton Bryan et al 2010, asserted that in as much as fog formation take place close to the earth surface, its water is contaminated with the product from various daily emissions that takes place making these water acidic and harmful to living organisms.
However, the National Geographical Society, NGS research reveals that “fog” shows up when water vapour, or water in its gaseous form, condenses. During this condensation, molecule of water vapour combine to make tiny liquid water droplets that hang in the air, and you can see fog because of these tiny water droplets. Depending on where and how the cooling effect takes place, the appearance and lasting duration of fogs are affected.
Fogs are mostly seen in some parts of the world like California (Western USA), Argentina (South America),Namibia (South West Coast of Africa), Italy, and New Foundland (North America) – the world’s foggiest place where the meeting of the warm Gulf Stream and the north Cold Labrador current makes the Grand Banks- a spot in the Atlantic Ocean.
Several times, people wake up to find the surroundings covered with a mass of water droplets which impairs human visibility and to a certain extent “dew” on object and surface. In Lagos State (South West Nigeria), witnessed a thick white fog looming up in the air and obscuring residential houses and offices at Ikeja, Ojota, Agege, Gbagada and Ketu on 13th October, 2005, (This Day Newspapers Lagos State, 2005).
Fog as an enemy of renewable energies means little to no sunshine or wind. This highlights a new challenge that renewable energies are a less constant source of power compared to fossil fuels. Therefore, energy storage has to increase dramatically, be it in the form of batteries, hydrogen or other technologies.
Mostly, you may have come across this weather phenomenon at various point in time. Today, Engineers are working on more sophisticated ways to collect water from fog. The most effective way has been the development of “fog catchers- large screens constructed in arid areas (Bellavista, Peru) where fog glides in and water droplets form around the thin screens and rip to the collection pools below. Here in one day, a single screen can collect more than a hundred gallons of water.
Humans and related systems around the world where fog occurs are influenced by it either directly or indirectly. Naturally occurring fog apart from reducing visibility can influence the vegetation, air quality, radiation budget which directly affects temperature and surface-air interaction. This reduction in visibility considerably impair transportation leading to various economic and financial problems including flight delays, airplane crashes, road accidents and ship wrecks.
Fog also contain aerosol (small liquid or solid particles suspended in the atmosphere, excluding large cloud or precipitation particles) which due to decreased insulation, harm agricultural productivity causing economic impact. Black carbon (soot) from incomplete burning of fossil fuels, biofuels, and biomass which has been found in large quantities in fog is a cause of high radiative forcing and causing atmospheric global warming. (Guttepe 2007 book: Fog and Boundary Layer Clouds).
However, due to vast humidity associated with fog, it has been noted that patients with asthma, coughs when they inhale fog. Also, foggy conditions lead to an increase in depression, respiratory and heart ailments according to proven research.
So, at low temperature where fog forms oxygen, the concentration is high and there is decreased rate of metabolism which reduces the respiration in animals, hence our ecosystem is jeopardized.
By Okoko Chidozie Christian
chidochrisozonegold@yahoo.com; 09025179984.
