Fog is a natural weather phenomenon that occurs when water vapor condenses into tiny liquid water droplets suspended in the air near the ground, reducing visibility. It is essentially a low-lying cloud and forms when the temperature of the air drops to the dew point, and the air becomes saturated with moisture.
Fog plays a significant role in weather patterns and transportation safety, particularly in regions with varying terrain and climates, such as the Sultanate of Oman.
How Does Fog Form?
Fog develops when air near the surface cools enough for its moisture to condense into tiny water droplets.
This happens when the air cools to its dew point ) the temperature at which it becomes fully saturated and condensation begins(. The cooling can result from several processes: radiative cooling during clear nights, air rising up slopes (causing it to expand and cool), warm moist air moving over a cooler surface (advection), or mixing of different air masses.
Moisture can also be added to the air through evaporation from water surfaces or damp ground, which can increase humidity to the point of saturation and result in fog.
Conditions that support fog formation include:
- Calm, windless nights
- Clear skies
- High humidity
- Proximity to water bodies (lakes, oceans)
On the other hand, certain factors prevent or break up fog by reducing moisture or warming the air:
- Strong winds
- Rain or thick cloud cover
- Very dry air
- Daytime warming from the sun
- Warming during the day
Although fog is more likely to form at night, it can occur any time the right conditions are met. It typically fades after sunrise as temperatures rise.
Types of Fog
Several types of fog are observed in Oman:
- Radiation Fog: forms during calm, clear nights when the ground cools by releasing heat into the atmosphere. As the ground loses heat, the air directly above it cools to its dew point, resulting in condensation. It frequently appears in valleys and low-lying regions.
- Advection Fog: forms when warm, moist air moves over a cooler surface, such as the cold sea or land cooled overnight, Seen mainly in coastal areas.
- Upslope Fog: forms when wet air moves up a mountainside, cools during its upward movement, and forms fog through condensation.
Fog Effects
Horizontal visibility, sometimes reduced to several meters, may cause traffic accidents, resulting in material and human losses.
Fog significantly impacts aviation safety and operations, as it leads to:
• Reduce horizontal visibility, which hinders takeoff and landing procedures.
• Flight delays or cancellations to prevent accidents.
• Interference with navigation systems if they are not equipped with advanced precision technologies.
Modern airports may use automatic landing systems to mitigate the impact of fog on flight operations.
Fog in Oman
The geography of Oman, which includes coastal plains, high mountain ranges, and expansive deserts, contributes to the diverse ways fog manifests across the country. In Oman, fog is most commonly observed in the coastal regions and highlands, especially during periods when moist air meets cooler ground surfaces.
The Sultanate of Oman experiences fog in several regions, with coastal governorates such as South Al Sharqiyah, Al Wusta, and Dhofar being the most affected. Additionally, inland governorates like Al Buraimi and Al Dhahirah occasionally experience radiation fog during cold nights.
Dealing with Fog
Oman employs several strategies to mitigate the effects of fog:
- Follow weather reports from official sources.
- Road users are advised to use fog lights, reduce speed, and maintain safe distances during foggy conditions
- For pilots and maritime navigation:
- Use modern navigation systems such as radar and GPS.
- Maintain constant communication with the air traffic control tower or ship monitoring centers.
- Delay trips if visibility is zero.