Chinese project could improve weather forecasting

Chinese scientists have completed a series of tethered balloon flights over the Tibetan Plateau, gathering rare high-altitude atmospheric data in a project they say could improve weather forecasting.

The Aerospace Information Research Institute of the Chinese Academy of Sciences said over the weekend that its Jimu 1 aerostat conducted 30 verification flights in Lunang, Xizang autonomous region, between Aug 12 and Sept 19.

Working with the Institute of Tibetan Plateau Research, the team measured atmospheric composition, pollutant distribution and three-dimensional cloud microphysics at varying altitudes and in different weather conditions.

Zhang Taihua, a senior engineer at the Aerospace Information Research Institute, said the tethered balloon carried 16 types of scientific payloads collectively weighing about 200 kilograms across three major categories. It ascended to 5,500 meters above sea level.

"Through coordinated multi-payload observations, the experiment marked a technological leap from single-point sampling to three-dimensional monitoring, laying a foundation for dynamic monitoring and sustainable development in the Qinghai-Tibet Plateau and other global climate change-sensitive areas," said Zhang, who is responsible for the project.

A tethered balloon is a lighter-than-air aircraft that generates lift by using a gas — typically helium — that is less dense than air. It predates the airplane and is regarded as one of the earliest types of aerospace vehicles, according to the research team.

He Zeqing, a senior engineer at the institute, said tethered balloons offer several advantages, including long endurance, wide coverage, flexible deployment, strong payload capacity and low operational costs.

"These features make them highly competitive and often irreplaceable in various applications compared to other types of aircraft," He said, adding that the Jimu 1 tethered balloon has emerged as a benchmark product, reflecting the level of independent innovation in China's airship observation field.

Since 2017, the aerostat has been involved in scientific expeditions, conducting systematic observations in areas such as Lunang, Namtso Lake, Mount Qomolangma — also known as Mount Everest in the West — and Tsonyi county in Xizang. It has conducted observations in the Hoh Xil area in Qinghai province and the Tashkurgan area in the Xinjiang Uygur autonomous region.

During the 2022 expedition, Jimu 1 set a world record by ascending to 9,050 meters, a height exceeding Mount Qomolangma's.

In recent years, the frequent occurrence of extreme rainfall events has made accurate forecasting of the location and amount of rainfall a major public concern.

Shang Huazhe, an associate researcher at the institute, said that predicting the amount of rain is the most challenging aspect of forecasting extreme rainfall, particularly in recent years as climate change has made extreme weather events more frequent.

"Sometimes, the rainfall amounts exceed both our previous understandings and the estimated values provided by current forecasting models. Such events urge us to deepen our understanding of natural conditions, which can help us overcome the current challenges in rainfall prediction," Shang said.

He said that compared with other regions, clouds over high-altitude areas have shorter life cycles, with faster development and dissipation processes.

"By detecting the distribution of microphysical properties at the cloud base, within the cloud and at the cloud top, as well as the characteristics of clouds at different life stages, researchers can obtain the data that helps improve the parameterization schemes in existing weather forecast models," Shang said.

"This is of great significance for accurately predicting rainfall locations and amounts."

Contact the writers at palden_nyima@chinadaily.com.cn