What does visibility mean in weather?
Visibility is how far a person can see and recognize objects clearly. It depends on the weather and air quality. This measure is very important for weather forecasting.
Many important factor affect it. These include water droplets, ice crystals, dust, smoke,dense fog and pollution. The angle of the sun compared to the horizon also plays a role.
In weather science, visibility shows how clear the air is and affects daily life, travel, and flight safety.
How is visibility assessed?
Researchers often measure visibility by looking at how light travels through the air. Here’s a simple explanation of the process:
Ground-based observation
Manual Observation: This is the oldest and most common method. A ground observer looks at a distant object target.
This target could be a black panel or a lighthouse. Observers use their eyes or binoculars to see how clearly they can view the target. This method is simple, but it depends on the observer’s personal judgment.
Employment of specialized equipment:
With new technology, tools like visibility meters and scattering meters are used to measure visibility. These devices send out a laser or light beam. They measure how much the beam is scattered or absorbed as it moves through the air.
Satellite:
Satellite images can show good visibility data over large areas. By studying the light reflected from the Earth, weather scientists can estimate visibility in different places.
Aerial surveillance
In aviation, pilots check visibility while flying. They depend on their eyesight, which is key for safety.
Some aircraft have automated systems. These systems check visibility and give accurate data. How do they measure visibility?
How is visibility determined?
Researchers often measure visibility by looking at how light travels through the air. Here’s a simple explanation of the process:
The climatic optical visual range (MOR) is the standard measure. MOR shows how far a straight light beam goes.
This beam comes from a lamp with a color temperature around 2700 K. The light’s brightness drops to about 5% of its original level due to the atmosphere weakening it.
In practical use, an automated device sends out a light beam. It measures how much the light weakens as it travels through the air. This weakening happens due to scattering or absorption. You can find the current visibility value by using this data and the MOR definition.
Reduced visibility depends on many factors, such as dust, humidity, and temperature. Because of this, researchers use special tools and methods to get accurate and reliable measurements.
In short, visibility shows how clear the air is. It is measured in different ways and can change with the weather. Visibility impacts aviation, road safety, and outdoor activities. Because of this, weather agencies around the world monitor it closely.
