New unmanned submersible developed to collect typhoon data and improve forecasting

Typhoons and their Atlantic counterparts—hurricanes—can develop into massively destructive storms that can take a severe toll on both infrastructure and human life. Climate change is additionally spurring even more intense storms with higher wind speeds and rainfall.

Typhoon-affected countries can reduce some of the devastating impacts of these storms through enhanced preparedness. However, typhoons remain extremely challenging to study in real time, largely due to their extreme winds and heavy rainfall—both over the ocean and on land. Despite this barrier, in situ storm data (gathered directly within the storm) is critical to improving the modeling and prediction of typhoons and other tropical cyclones.

According to researchers, there are three main challenges to obtaining tropical cyclone data directly from the storm: 1) Real-time alignment with a cyclone’s path, 2) Acquisition of upper- ocean data during a cyclone and 3) Integration of satellite and buoy data to enhance observational data. Up to this point, the majority of the field’s in situ storm data relied on remote-sensing satellite data complemented by sparse anchored/drifting buoy networks, making data collected within cyclones scarce.

To address these challenges, a research team from the Marine Intelligent Unmanned Equipment Innovation Team at the Southern Marine Science and Engineering Guangdong Laboratory in Zhuhai, China recently unveiled the “Blue Whale”: an 11-meter submersible unmanned vessel (SUV) developed as a core component of the Intelligent Swift Ocean Observing System (ISOOS). Its design enables more effective measurement of in situ cyclone data while eliminating risks to human life.

The researchers published their study in the July 31 issue of the journal Ocean-Land-Atmosphere Research.

In order to obtain reliable data within tropical cyclones, the team leveraged fully submersible vehicle technology to maximize vehicle stability in high-wind and -rainfall conditions.

“Unlike conventional surface vessels, [semisubmersible or submersible] hulls remain predominantly or entirely submerged during operation. This submerged configuration significantly attenuates wave-induced motions, enables enhanced [vehicle stability] and considerably enhances operational resilience in adverse sea conditions,” said Chao Dong, director of the Key Laboratory of Marine Environmental Survey Technology and Application in Guangzhou, China and first author of the research paper.

The team successfully combined the advantages of both unmanned surface vehicles and unmanned submersibles to develop a vehicle uniquely tailored for collecting data in cyclone conditions. Above water, the Blue Whale utilizes a conventional propulsion system for high-speed surface navigation; underwater, it employs a vector propulsion system, composed of four vector thrusters, for low-speed operations. The SUV is also equipped with a sinking and floating system, an anchoring system and a gravity adjustment system to facilitate fixed-point underwater hovering.

Despite the need for this type of vehicle for data collection in poor sea conditions, this is the first published report of an unmanned, fully submersible vehicle in the literature to date. The team reports that the Blue Whale boasts the following capabilities: 1) A maximum surface velocity of 23 knots and operational range of over 200km in optimal sea conditions, 2) A maximum submerged speed of 3 knots and sustained submerged operation at maximum speed for about 4 hours, 3) The capacity to remain submerged in standby mode for up to 72 hours without surfacing and 4) The ability to carry a 800 kg payload.

The Blue Whale payload consists of operational equipment for in situ cyclone data collection.

“During submerged operations, its sensor suite—including an acoustic Doppler current profiler, conductivity–temperature–depth sensors, and biochemical sensors for pH, chlorophyll, and turbidity—collects comprehensive water column parameter data,” Dong explained. During surface operations, the SUV can also deploy research rockets to gather atmospheric profile data. Critically, the Blue Whale platform leverages structural optimization and real-time movement and orientation prediction algorithms to improve research rocket success rates in adverse conditions.

While initial testing of the Blue Whale has yielded promising results, the SUV is not yet ready for full operational use. Following internal debugging, mooring trials, dock trials and sea trials, the platform is scheduled for operational deployment in typhoon observation by 2026.

“The Blue Whale’s ability to operate in extreme sea states while maintaining sensor stability represents a significant advancement in marine meteorological observation technology. This innovation directly enhances disaster preparedness by enabling more accurate typhoon intensity forecasts and marine condition warnings,” Dong noted.

Guosong Wu and Yunfei Zhang from the Southern Marine Science and Engineering Guangdong Laboratory and Zhuhai Yunzhou Intelligence Technology Co., Ltd. in Zhuhai, China; Han Zhang from Second Institute of Oceanography at the Ministry of Natural Resources in Hangzhou, China; and Qisen Wang from the Key Laboratory of Marine Environmental Survey Technology and Application at the Ministry of Natural Resources in Guangzhou, China and the Southern Marine Science and Engineering Guangdong Laboratory in Zhuhai, China also contributed to this research.

This research was supported by the National Natural Science Foundation of China (42227901).