Tethered Balloon Takes Closer Look at Clouds over Qinghai-Xizang Plateau
30 Sep 2026
Scientists have used a tethered balloon to measure cloud droplets, aerosols, and electric fields over the Qinghai-Xizang Plateau, revealing links between aerosol abundance and droplet properties and documenting weak electrical activity in clouds without lightning. The study was published in Advances in Atmospheric Sciences .
Led by Prof. HUSI Letu at the Aerospace Information Research Institute of the Chinese Academy of Sciences (AIRCAS), with collaborators across China, the study reports a comprehensive tethered-balloon campaign specifically designed to investigate these properties simultaneously over the plateau.
A tethered balloon prepares for launch over the Qinghai-Xizang Plateau. (Image credit: WANG Hengqi)
Clouds play an important role in Earth's climate and water cycle, yet their internal processes are difficult to observe. Unlike aircraft, which must keep moving, a tethered balloon can slowly ascend, descend, or remain within a cloud, allowing detailed measurements at different heights.
During the campaign in Lulang in the southeastern part of the plateau, researchers combined balloon measurements of cloud droplets, aerosols, weather conditions, and electric fields with ground observations and satellite data. "With the tethered balloon, we can stay in the cloud and observe how its microphysical and electrical properties change with height," said Assoc. Prof. SHANG Huazhe, who helped design and coordinate the campaign.
Higher aerosol abundance near cloud base was associated with more numerous, smaller droplets above, as well as increased cloud water. This relationship was particularly clear under the relatively clean conditions of the plateau, where the availability of particles on which droplets form may help control cloud development. Asst. Prof. WANG Hengqi, who studies aerosol-cloud interactions and participated in the campaign, cautioned that further observations are needed to determine whether this apparent sensitivity to aerosols is widespread across the plateau.
Droplets generally grew larger and cloud water increased with height, consistent with growth through condensation. Droplet numbers decreased in some cloud profiles, possibly because surrounding air mixed into the clouds and diluted the droplet population.
Previous studies of cloud electrification have focused largely on thunderstorms, where charge separation can generate strong electric fields and lightning. In contrast, this campaign examined warm clouds without lightning. Electric fields were generally weak, with no clear linear relationship between field variations and droplet number or size. Field strength also differed little inside and outside the clouds.
The findings suggest that the surrounding atmospheric electrical environment, as well as the clouds themselves, may influence local electric fields. Some electric-field variability was nevertheless observed. Whether warm clouds influence atmospheric electrical activity on larger scales remains an open question.
The campaign demonstrates the value of tethered-balloon observations for studying clouds over complex terrain. "This campaign is only a beginning," said Prof. HUSI Letu. To build a broader picture, the team plans to expand observations across seasons and compare warm, mixed-phase, and ice clouds. Combining balloon measurements with aircraft, satellite, and ground-based radar observations could help clarify the connections among aerosols, clouds, precipitation, and electrical processes.
Collaborating institutions included the Institute of Tibetan Plateau Research, the Institute of Atmospheric Physics, Xi'an University of Technology, the National University of Defense Technology, the National Satellite Meteorological Center, Peking University, and Tsinghua University.
Citation: Letu, H. S., and Coauthors, 2026: Exploring cloud microphysics and electric fields in non-lightning clouds over the Third Pole: First results from a tethered-balloon campaign. Adv. Atmos. Sci., https://doi.org/10.1007/s00376-026-6361-5.
Research News
Tethered Balloon Takes Closer Look at Clouds over Qinghai-Xizang Plateau
Scientists have used a tethered balloon to measure cloud droplets, aerosols, and electric fields over the Qinghai-Xizang Plateau, revealing links between aerosol abundance and droplet properties and documenting weak electrical activity in clouds without lightning. The study was published in Advances in Atmospheric Sciences .
Led by Prof. HUSI Letu at the Aerospace Information Research Institute of the Chinese Academy of Sciences (AIRCAS), with collaborators across China, the study reports a comprehensive tethered-balloon campaign specifically designed to investigate these properties simultaneously over the plateau.
A tethered balloon prepares for launch over the Qinghai-Xizang Plateau. (Image credit: WANG Hengqi)
Clouds play an important role in Earth's climate and water cycle, yet their internal processes are difficult to observe. Unlike aircraft, which must keep moving, a tethered balloon can slowly ascend, descend, or remain within a cloud, allowing detailed measurements at different heights.
During the campaign in Lulang in the southeastern part of the plateau, researchers combined balloon measurements of cloud droplets, aerosols, weather conditions, and electric fields with ground observations and satellite data. "With the tethered balloon, we can stay in the cloud and observe how its microphysical and electrical properties change with height," said Assoc. Prof. SHANG Huazhe, who helped design and coordinate the campaign.
Higher aerosol abundance near cloud base was associated with more numerous, smaller droplets above, as well as increased cloud water. This relationship was particularly clear under the relatively clean conditions of the plateau, where the availability of particles on which droplets form may help control cloud development. Asst. Prof. WANG Hengqi, who studies aerosol-cloud interactions and participated in the campaign, cautioned that further observations are needed to determine whether this apparent sensitivity to aerosols is widespread across the plateau.
Droplets generally grew larger and cloud water increased with height, consistent with growth through condensation. Droplet numbers decreased in some cloud profiles, possibly because surrounding air mixed into the clouds and diluted the droplet population.
Previous studies of cloud electrification have focused largely on thunderstorms, where charge separation can generate strong electric fields and lightning. In contrast, this campaign examined warm clouds without lightning. Electric fields were generally weak, with no clear linear relationship between field variations and droplet number or size. Field strength also differed little inside and outside the clouds.
The findings suggest that the surrounding atmospheric electrical environment, as well as the clouds themselves, may influence local electric fields. Some electric-field variability was nevertheless observed. Whether warm clouds influence atmospheric electrical activity on larger scales remains an open question.
The campaign demonstrates the value of tethered-balloon observations for studying clouds over complex terrain. "This campaign is only a beginning," said Prof. HUSI Letu. To build a broader picture, the team plans to expand observations across seasons and compare warm, mixed-phase, and ice clouds. Combining balloon measurements with aircraft, satellite, and ground-based radar observations could help clarify the connections among aerosols, clouds, precipitation, and electrical processes.
Collaborating institutions included the Institute of Tibetan Plateau Research, the Institute of Atmospheric Physics, Xi'an University of Technology, the National University of Defense Technology, the National Satellite Meteorological Center, Peking University, and Tsinghua University.
Citation: Letu, H. S., and Coauthors, 2026: Exploring cloud microphysics and electric fields in non-lightning clouds over the Third Pole: First results from a tethered-balloon campaign. Adv. Atmos. Sci., https://doi.org/10.1007/s00376-026-6361-5.