Weather is the atmosphere’s condition (mainly troposphere- the bottom layer of the atmosphere) during a short period at a specific area. The weather varies from climate to climate. The weather includes all the atmospheric occurrences like wind, air, air pressure, type and quantity of rain (precipitation), humidity, perceived temperature, visibility, cloud, etc. As the weather and the wind direction significantly impact the human establishment and different activity types, it is necessary to know the wind’s direction.
A weathervane or wind vane is a moving device generally placed on the rooftop or building’s top to show the wind’s direction. These were manufactured in China and Greece. The Greek people used to fix this instrument on the top of the wind towers, whereas roosters were placed above the weather vanes in America and Europe. This method was found successful because of the morphology of the rooster. The weathervane was made to catch the wind. Today, various advanced types of weather vanes are available, and these vanes are lightweight and decorative and durable, corrosion-resistant, and used in vast areas.
A brief history on weather vanes
The weather vanes underwent various changes in their shapes and designs by passing years and centuries from the triton’s shape holding a rod to different birds’ structure. Gallo di Ramperto, made in 820 CE, is the oldest weather vane, and the shape is a rooster. In the 9th century, every church had this rooster shape weather vane on their tops. The ancient weather vanes had very decorative direction-spinning pointers generally built from bronze. They had a fish on their tail. During medieval times in Europe, communal buildings had weather vanes. In this period, the people who were engaged in archery use it to estimate the wind’s speed and direction. At that time, a very popular weather vane was made in America that is grasshopper shaped. But today’s weather vanes were a very minimal simple structure as various light digital elements were attached to it, and they not only showed the wind direction but multifunctional.
Let’s dive deeper into more detail about weather vanes.
The working mechanism of weather vanes
- There are generally two types of weather vanes. The first one is simple, and the second one is advanced. The simple weather vanes have equally distributed weight throughout the surface area with unequal shape. Here the lighter surface area pointed towards the wind. The advanced weather vanes are a little complex as they use an anemometer to measure air pressure and calculate its velocity. The combination of a weather vane with an anemometer is referred to as aero vane. The wind vanes with propeller anemometer are reliable for measuring an average wind speed.
- The weather vane is attached to the top point of a building, and it shows the direction of the wind, which is why it is also called a wind vane. It has a free-spinning directional pointer. It is quite necessary to have this pointer fragile. The free-spinning directional pointer can be achieved by distributing the weight equally in both the vane axis. The two points must be unequal in size; that is, one should be small, and the other should be large. The wind comes from the smaller endpoint and exits through the larger endpoint.
- Another basic yet important rule that should be emphasized while constructing a weather vane is that the direction’s marking point needs to be lined up with the topographical directions of North, South, East, and West. This ensures easy identification of the direction.
- Various aspects must be prioritized while constructing a weather vane. The most important aspect is the balance. The form of a weather vane should be correct. If the shape and balance are altered, it fails to move according to the wind, hence failing to show the wind’s direction. The weather vane should be placed in the topmost aerial position of a building, ensuring no nearby highest point other than the building the vane is placed; otherwise, it may not show the wind’s proper direction and cause an imbalance.
- The weather vanes have rotating horizontal arrows that point in the coming wind’s direction, which is achieved through the divergent surface area on either side of the arrow. The surface area of the arrow’s tail is lighter while the head is heavier, which enables wind catching of the lighter end. When the breeze catches the heavy end of the free-spinning directional pointer, it fluctuates in the direction of the wind. If the arrow is pointing towards the E marker on the wind vane, then it indicates the wind is flowing from the East direction to the West. Likewise, if the arrow points towards the S marker, wind flows from the south towards the north of the geographic direction.
- Sometimes, there are various basic components coupled with the weather vane and makes it more useful. This type of weather vanes is also called digital weather vanes. It generally sits on the aerial top of a building or tall pole and rotates on a spindle. An optical sensor is attached to one end of the spindle, which allows these digital elements to recognize the wind’s direction. The observation displayed on the digital screen like a rounded graphic called a wind rose. This digital type of weather vanes also displays precipitation, humidity, wind speed, pressure, etc.
The uses of the weather vanes
- One of the best uses of the weathervane is forest observing. The weathervane shows the direction and measures the speed of the wind with the help of an anemometer. The wind’s observation is a delicate task as a little hurdle, unlike a tree nearby or any other reason ruins the whole balance and gives a false read. So it must be placed at the highest point, at least above a standard height of 10 to 15 meters, to ensure uninterrupted wind checking. The task is so sensitive that there should be no hurdles anywhere near the instrument. We can call this an open territory. The reason for this precaution is to avoid observing the wind instability created by the obstacle.
- The propeller anemometer is the appropriate instrument to measure the parallel wind speed. The propeller anemometer has the lowest starting point of wind speed, and it is a high accuracy instrument. With the weather vanes, a sonic anemometer and hot wire anemometer are also used. One thing to be focused on here is that the wind direction must point towards the north.
- Since the Roman Empire, there have been significant uses of the weather vanes. With a simple structure, the wind vanes give a quick idea of wind direction. For centuries, farmers are using this technique. Even though they have more advanced techniques to observe the wind direction in the modern world, some are still using wind vanes above the heightened pool in their crop fields. This technique knows exactly where the current air is breezing as the wind affects various outside activities.
- Now the weathervanes come with different types of art and design. So people use this as a decorative piece on many buildings and houses. In houses and buildings, these weather vanes are also used in various structures, sheds, and barns for an ornamental purpose. The simplest of the weather vanes are now found on the aerial top of farmhouses or on the crop field where farmers used them. Different hand-crafted designs of the weather vanes are found on the top of courts or museums. The weather vane design also indicates the theme or core message of the building where they are placed.
- The weather vanes are also attached primarily to the boats for navigation purposes. In ancient times, the wind vanes used to be the only option for navigating the accurate root. Today also, if the motorboat fails, the only and appropriate technique for the wind’s exact direction is measured by a weather vane. When all other direction-finding devices fail, the weather vanes are the only instrument that indicates the sailors in which direction they should lead to reach a safe place and in which direction the wind is taking them. It is done by placing the weather vane at a certain angle with the wind, and a coupled mechanism of rope with rubbers stabilizes the boat with the wind at a constant angle.
- The weather vanes helpful in life-saving and these instruments play a vital role in sports like golf. In golf, a tiny mobile wind vane tool is attached to the golf equipment to indicate the golf player where the wind is breezing. This information helps the golfers to score well by letting them know how to aim and give their shot perfect timing so that the ball finds its destination, that is, the hole. The weather vane is also helpful in the marina, baseball, etc., where wind speed and wind direction play a role.
- During hazardous climatic conditions like storms, the weather vane lets us know how direction the wind is blowing so that both can save lives and belongings to a certain extent. In this situation, the wind vane also helps local governments or authorities keep their citizens safe by pre-arranging safe buildings where the storm’s impact is less and shift their citizens into those buildings.
- The assessment of weather and its changing pattern and condition mainly needs a weather vane. The meteorologists predict a change in weather by observing and monitoring the weather vane. Like if the weather vane changes from the west direction, then it may be an indication of low pressure. These weather vanes are also used in agriculture by predicting the change in weather conditions, like how much it will rain in that particular area. Accordingly, the farmers of that area schedule their cultivation by choosing the right type of crops that suits that specific area’s climate.
- Although today’s hi-tech instruments did all the jobs, some part of the population like air traffic managers and sometimes pilots use weather vanes to observe from which direction the wind is blowing and controlling their speed when landing or taking accordingly. These wind vanes generally come with a sock, and due to the sock’s inflation, the pilots or traffic controllers estimate the strength of the wind.
- By installing a weather vane, one can master reading the local weather condition with a focused observation and predict the upcoming disaster and help humanity to a great extent.
Sometimes spider webs cause an electric short and damage the weather vanes. Not only animals, but the weather vanes get damaged by several human activities also. Gunshot, any other accidents, or damaging the sensor while playing baseball, golf can cause damage to the weather vanes, resulting in an error in monitoring wind direction and wrong estimation of wind speed. Extreme weather conditions can also damage the weather vanes to a larger extent. So it is necessary to check the functionality of the sensors used inside the weather vane regularly to ensure proper monitoring of the instrument. Keep in mind, a single error in the weather vane contributes to the weather’s false observation.
The Bottom Line
To summarize, weather vanes are instruments of different shapes and designs used to know the proper direction from where the wind is blowing. You may notice some practical reasons that cause trouble for the functioning of the wind vane. One of such reasons is trouble due to animals. Sometimes large birds banged on the weather vanes and damaged them.