National Space Science Center Derives New Chemical Heating Rate Data Product for Mesopause Region Based on OH Airglow Observations

Recently, researchers from the State Key Laboratory of Solar Activity and Space Weather at the National Space Science Center, Chinese Academy of Sciences (CAS), in collaboration with partners, utilized OH airglow spectral data observed by the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) aboard the European environmental satellite Envisat to retrieve a new dataset of nighttime chemical heating rates in the mesopause region, and systematically studied its spatial distribution and seasonal variation characteristics. This research deepens the understanding of the spatiotemporal variation patterns of chemical heating in the mesopause region and provides independent observational evidence for constraining the energy budget of the mesopause. The research was supported by the Ground-based Space Environment Monitoring Network (CMP), and the findings have been published in Atmospheric Chemistry and Physics.

Source: National Space Science Center, Chinese Academy of Sciences

EarthLab Supports New Framework for Rapid Diagnosis of Extreme Events: A Quantitative Method Based on AI Forecasting and Green’s-Function-Like Experiments

Recently, a research team from the Institute of Atmospheric Physics, Chinese Academy of Sciences, developed a sensitivity reforecast diagnostic framework based on AI weather forecasting models. Leveraging the efficient and stable reforecasting capabilities of AI forecasting models, the team conducted systematic regional Green’s-function-like experiments targeting specific extreme events. Based on changes in forecast results and forecast skill, they quantitatively assessed the influence of different global regions on the onset, development, and intensification of target heatwave events. Building on this framework and integrating AI agents with automated analysis workflows, it is expected to enable rapid identification, quantitative diagnosis, and mechanistic analysis of extreme events, pushing extreme event diagnosis research toward greater efficiency, systematicity, and intelligence. The research was supported by the Earth System Science Numerical Simulator Facility (EarthLab), and the findings have been published in Geophysical Research Letters.

Source: Earth System Science Numerical Simulator Facility (EarthLab)

3. Institute of Physics Achieves Important Progress on Terawatt-Class Broadband Tunable Terahertz Radiation Source

Recently, a research team from the Institute of Physics, Chinese Academy of Sciences / Beijing National Laboratory for Condensed Matter Physics utilized the interaction between high-contrast ultraintense femtosecond lasers and metal thin films. By manipulating the spatiotemporal evolution dynamics of laser-accelerated electron beams, they elevated the terahertz radiation peak power to the terawatt level. Extreme terahertz sources are expected to provide unique pumping means for selective manipulation of nonequilibrium states of matter, pushing terahertz wave-matter interactions into the relativistic optics regime previously unattainable, with important applications in materials science, biomedicine, and other fields. The experiments were conducted on the petawatt laser facility at the Ultrafast X-ray Dynamics Experimental Station of the Synergetic Extreme Condition User Facility (SECUF). The findings have been published in Optica.

Source: Institute of Physics, Chinese Academy of Sciences

Institute of Mechanics Makes Progress on Thermomechanical Coupling Deformation of Pre-stressed Compressed Spherical Shells

Recently, a research team from the State Key Laboratory of Nonlinear Mechanics at the Institute of Mechanics, Chinese Academy of Sciences, established an analytical solution for the thermomechanical coupling deformation of pre-stressed compressed spherical shells based on invariant theory. This research extends classical spherical shell inflation theory and provides a theoretical framework for analyzing the coupled deformation of spherical shells under complex environments. The theory helps reveal, from a mechanistic perspective, the variation patterns of pore volume and stress in deep shale during burial, thermal evolution, and changes in internal and external pressure, offering theoretical references for the development of deep unconventional oil and gas resources and laying the foundation for subsequent research on mechanical responses under more realistic geological conditions (such as non-uniform temperature, more complex loading, and structural instability). The findings have been published in International Journal of Mechanical Sciences.

Source: Institute of Mechanics, Chinese Academy of Sciences

Tsinghua University Publishes Multiscale Atlas of CO₂ Emissions from Global Trade-Related Transportation

Recently, the He Kebin–Liu Huan research team from the School of Environment at Tsinghua University constructed a machine-learning-based comprehensive analysis framework covering 65 economies, approximately 1.9 million bilateral trade flows, and 1,221 categories of goods to estimate the modal share of various goods in bilateral trade flows transported by sea, air, road, and rail. On this basis, they quantified the CO₂ emissions from international trade-related transportation. Multiscale modal share data reveal the heterogeneity of CO₂ emissions at different scales while highlighting cognitive differences in the attribution of emissions. By expanding the emissions reduction perspective from the vehicles themselves to the optimization of commodity flows and trade relationships, this research helps provide new policy insights for international freight emissions reduction. The findings have been published in Science Advances.

Source: School of Environment, Tsinghua University