China launches new communications satellite

China sent a new communications satellite into orbit at 20:25 Beijing Time on Thursday.

The ChinaSat 4A satellite was launched atop a modified Long March-7 carrier rocket from the Wenchang Space Launch Site in the southern Hainan Province.

The satellite will provide voice, data, radio and television transmission services.

The launch was the 532nd flight mission of the Long March series rockets.

China's scientific expedition team on Thursday obtained critical ice cores during their investigation of the Qinghai-Xizang Plateau, which is known as Asia's "water tower".

The region encompasses "one glacier, two lakes and three rivers". It is home to Purog Kangri Glacier, the world's largest glacier in the mid to low-latitude regions, as well as Siling Lake and Namtso Lake, the largest and second-largest lakes in Xizang, respectively. It is also the birthplace of the Yangtze River, Nujiang River and Yarlung Zangbo River.

The climate in the region is complex and changeable, and its ecosystem is very fragile, and meanwhile it is a pivotal area for Xizang's economic and social development.

During their expedition, the team drilled for ice cores at different depths overnight on Thursday, aiming to capture climate records from different time scales.

Ice core drilling is typically conducted during the night and early morning when the ice temperature is sufficiently low.

Ice cores serve as vital records of global climate and environmental changes. The sediments and bubbles within these cores are clues to understanding the history of Earth's climate. By studying the bubbles captured in ice cores, scientists can analyze atmospheric composition, including carbon dioxide levels, over hundreds of thousands of years.

Yao Tandong, an academician at the Chinese Academy of Sciences (CAS) and leader of the expedition, and Lonnie Thompson, a renowned American glacier expert and foreign academician at CAS, conducted their scientific expedition on the glacier Thursday morning.

Through helicopter observations, thickness-measuring radar, satellite image comparison and other methods, the scientific expedition team has found that the surface area of the Purog Kangri Glacier has shrunk by 10 percent over the past 50 years.

The average altitude of Purog Kangri Glacier is 5,748 meters, with the highest point reaching 6,370 meters. Due to global warming, the glacier is melting rapidly.

"So does the melting of glacier surface -- the higher the altitudes, the less the ablation volume, while at lower altitudes, it accumulates and forms branch-like rivers on the ice surface. Currently, these branches extend up to altitudes of 6,000 meters," said Xu Baiqing, a research fellow of the Institute of Tibetan Plateau Research under the CAS.

Research indicates that the accelerated retreat of glaciers on the Qinghai-Xizang Plateau over the past 40 years reflects a broader trend, and the melting rate of the Purog Kangri Glacier is relatively slow compared to the overall situation of the plateau.

The temperature changes within the glacier also attributed to the great difficulty of drilling, said Xu.

"Due to climate warming, the temperature within the glacier has risen, which suggests that under the same backdrop of temperature variations, the ablation may show abrupt shift with accelerating growth," said Xu.

The expedition was launched on Aug 18, 2024 and is scheduled to continue until October.