MOUNT CHO OYU BASE CAMP, Tibet, Oct. 1 -- A Chinese expedition team comprising 18 members reached the summit of Mount Cho Oyu, also known as Mt. Qowowuyag, at 9:15 a.m. on Sunday to carry out scientific research on the world's sixth-highest peak.

This is the first time Chinese scientists have scaled a peak exceeding 8,000 meters in altitude apart from Mt. Qomolangma, the world's highest summit.

Located on the China-Nepal border, Mt. Cho Oyu is the sixth-highest mountain in the world with an altitude of 8,201 meters.

The expedition carried out a number of tasks such as setting up automatic weather stations at extremely high altitudes, measuring the thickness of snow and ice on the summit, drilling ice cores and collecting snow and ice samples.

An Baosheng, the on-site commander of the expedition, said the scientists focused on major issues such as changes in Asia's "water tower," ecosystem and carbon cycle, human activities and the safety of the living environment, mineral resources and geological environment, hopefully to better understand the impact of changes in extremely high-altitude areas and extreme processes on the ecological environment of the Qinghai-Tibet Plateau.

"This expedition is of great scientific significance," said Yao Tandong, an academician with the Chinese Academy of Sciences (CAS). Mt. Cho Oyu has the thickest ice and snow on its summit among all the peaks exceeding 8,000 meters in altitude, and holds the potentially richest archive of extremely high-altitude climate change.

The mountain boasts the best area to study the effects of glacier retreat on periglacial ecosystem, as well as the processes of carbon source and carbon sink, and also the ideal area to carry out dynamic investigation of human health at extremely high altitude, Yao said.

The expedition team departed from the assault camp at 5,700 meters in altitude on Friday.

Five automatic weather stations have been set up at altitudes of 4,950, 5,700, 6,450, 7,100 and 8,201 meters on Mt. Cho Oyu, which will help reveal characteristics of climate change in extremely high-altitude areas, said Zhao Huabiao, a researcher with the Institute of Tibetan Plateau Research under the CAS.

After the expedition team set up a weather station at the altitude of 8,201 meters, the meteorological data was successfully transmitted, showing that the temperature at the summit of Mt. Cho Oyu was minus 18 degrees Celsius.

The weather stations are powered by solar panels and can run for two years under normal circumstances. Their daily work is to transmit meteorological information such as temperature, humidity, wind direction and speed, and solar radiation through satellite communication and other means.

The data will fill the blank in the meteorological record in extremely high-altitude areas, and is of great significance for monitoring the changes of glaciers and snow cover at high altitude, Zhao added.

The summit of Mount Cho Oyu is fairly wide, which is very rare among the highest peaks in the world. According to the preliminary research, the ice on the summit could be as thick as more than 70 meters, and the ice cores are of good quality, Yao said.

The expeditionists drilled an ice core of 10 meters long every 100 meters down from the summit. The ice cores will be transported to the freezer at the base camp at an altitude of 5,700 meters for preservation.

According to Yao, the ice core samples are expected to reveal the process and mechanism of the cryosphere change of the region in recent years, and provide scientific support for the ecological protection of the Qinghai-Tibet Plateau.

The 2023 Mt. Cho Oyu research mission is part of the second comprehensive scientific expedition on the Qinghai-Tibet Plateau initiated in 2017. In 2022 and 2023, the Chinese scientists have carried out the Mt. Qomolangma expedition for two consecutive years, setting a number of world records.

"On the basis of the Mt. Qomolangma missions, the Mt. Cho Oyu expedition is a multi-disciplinary interdisciplinary comprehensive scientific research at extremely high altitudes," Yao said.

Since the end of September, a total of 120 scientists have been conducting research on water, ecology and human activities around the mountain.