A rawinsonde is a device used to make meteorological observations in the upper air above the Earth's surface. Along with numerous other probes and devices, rawinsondes return data that can be used to learn more about weather systems. They are also used in weather forecasting, identifying patterns which can be linked with emerging weather systems so that members of the public can be alerted to anticipated weather conditions.
This device is a type of radiosonde. Radiosondes have been in use in meteorology since the 1920s, when the first one was sent aloft over France. These devices are designed to take readings and to transmit data to a receiver on Earth. Modern radiosondes are very sophisticated and may be capable of taking numerous readings including temperature, pressure, geographic location, altitude, and humidity. This data is sent to weather stations around the world.
The rawinsonde is capable of tracking wind speed as well as wind direction. It can be attached to a weather balloon with a suite of weather instruments or sent up alone. Rawinsondes can also be designed to take other types of weather readings, functioning as multipurpose radiosondes. In addition to being tracked with a radio, the rawinsonde can also be followed on a radar.
When a weather balloon comes back to Earth, the attached devices can be removed, inspected, and then set up for another launch. Weather monitoring equipment can be quite costly and it is generally designed to be durable and reusable, although weather balloons do get lost on occasion and sometimes instruments become dislodged or damaged while they are deployed. A rawinsonde can be vulnerable to damage in harsh weather due to the delicacy of the sensors used to monitor the wind.
Rawinsonde observation allows meteorologists to track and study wind patterns. Understanding the movement of wind in the upper air is critical not only for weather forecasting but also for long term study of the weather. Meteorologists use this data to learn more about shifts in the weather, to examine the interconnected nature of weather events, and to gather information which can be used in reconstructions to find out about the weather of the past.
In the event that one encounters a downed weather balloon and instruments, the equipment is usually marked with information identifying the agency which launched it, and it will appreciate a phone call. A representative can be sent out to collect the weather balloon and attached scientific instruments.