Rocketsondes, which are a type of sounding rocket, are used to make high-altitude weather observations – they can go higher than weather balloons. Given that they require launch sites, they're not used over the ocean as much as they're used over land. That could change, though, as Chinese scientists have now launched one from an autonomous semi-submersible vehicle.

Typically, for making meteorological observations over the sea, dropsonde parachutes and driftsonde balloons are used. The former are dropped from aircraft and use attached instruments to record atmospheric data as they fall, while the latter record such data as they drift in the stratosphere for days to weeks at a time.

According to the Chinese Academy of Sciences, however, neither are sufficient for accurately assessing marine weather. And while rocketsondes can be launched from ships, those vessels are big, expensive, they require crews, and they can't be used in overly-rough waters.

With that in mind, scientists from the academy developed a unmanned semi-submersible vehicle (USSV) that can travel almost anywhere in the ocean. In recently-conducted trials, it successfully launched a rocketsonde while at sea – instruments carried by that rocket proceeded to make real-time measurements such as the sea surface temperature, along with obtaining vertical profiles of the pressure, temperature, relative humidity, wind speed, and wind direction.

It is now hoped that once the technology is developed further, connected networks of the long-duration USSVs could be distributed throughout the world's oceans. The vehicles could not only record marine weather data, but may also be used to study the sea itself.

"We are currently developing a new generation of USSVs which can carry various sensors relevant to marine science, including conductivity/temperature/depth, acoustic Doppler current profiler, and motion sensors to provide vertical profiles of the conductivity, water temperature, current velocity, and wave height and direction," says Prof. Chen Hongbin, lead author of a paper on the research. "With that, a new interconnected USSV meteorological and oceanographic (METOC) observation network system will be developed."

The paper was recently published in the journal Advances in Atmospheric Sciences.