We’ve been measuring wind speed using anemometers for centuries, but recent advances have made it possible to provide more reliable and accurate weather forecasts. Sonic anemometers measure wind speed quickly and accurately compared to traditional versions.
Atmospheric science centers often use these devices when conducting routine measurements or detailed studies to help make accurate weather forecasts for various locations. Certain environmental conditions may limit measurements, but certain adjustments can be made to overcome these problems.
Anemometers appeared in the 15th century and have continued to be improved and developed in recent years. Traditional anemometers, first developed in the mid-19th century, use a circular arrangement of wind cups connected to a data logger. In the 1920s, they became three, providing a faster, more consistent response that helps measure wind gusts. Sonic anemometers are now the next step in weather forecasting, providing greater accuracy and resolution.
Sonic anemometers, developed in the 1970s, use ultrasonic waves to instantly measure wind speed and determine whether sound waves traveling between a pair of sensors are being accelerated or slowed down by the wind.
They are now widely commercialized and used in a variety of purposes and locations. Two-dimensional (wind speed and direction) sonic anemometers are widely used in weather stations, shipping, wind turbines, aviation, and even in the middle of the ocean, floating on weather buoys.
Sonic anemometers can make measurements with very high time resolution, typically from 20 Hz to 100 Hz, making them well suited for turbulence measurements. Speeds and resolutions in these ranges allow for more accurate measurements. The sonic anemometer is one of the newest meteorological instruments in weather stations today, and is even more important than the wind vane, which measures wind direction.
Unlike traditional versions, a sonic anemometer requires no moving parts to operate. They measure the time it takes for a sound pulse to travel between two sensors. Time is determined by the distance between these sensors, where the speed of sound depends on temperature, pressure and air contaminants such as pollution, salt, dust or mist in the air.
To obtain airspeed information between sensors, each sensor alternately acts as a transmitter and receiver, so pulses are transmitted between them in both directions.
Flight speed is determined based on the pulse time in each direction; it captures three-dimensional wind speed, direction and angle by placing three pairs of sensors on three different axes.
The Center for Atmospheric Sciences has sixteen sonic anemometers, one of which is capable of operating at 100 Hz, two of which are capable of operating at 50 Hz, and the rest, which are mostly capable of operating at 20 Hz, are fast enough for most operations.
Two instruments are equipped with anti-ice heating for use in icy conditions. Most have analog inputs, allowing you to add additional sensors such as temperature, humidity, pressure and trace gases.
Sonic anemometers have been used in projects such as NABMLEX to measure wind speeds at different heights, and Cityflux has taken different measurements in different parts of the city.
The CityFlux project team, which studies urban air pollution, said: “The essence of CityFlux is to study both problems simultaneously by measuring how quickly strong winds remove particulate matter from a network of city street ‘canyons’. The air above them is where we live and breathe. A place that can be blown away by the wind.”
Sonic anemometers are the latest major development in wind speed measurement, improving the accuracy of weather forecasts and being immune to adverse conditions such as heavy rain that can cause problems with traditional instruments.
More accurate wind speed data helps us understand upcoming weather conditions and prepare for daily life and work.
Post time: May-13-2024