Large-scale inverted-V channels of upflowing oxygen ions pumped by Alfvén waves

Large-scale inverted-V channels of upflowing oxygen ions are frequently identified in data collected by Cluster,at all local times,near the open-closed field line boundary over Earth’s high-latitude ionosphere-occur with downward propagating MHD Alfvén waves which have cascaded into kinetic regimes of plasma.The transverse acceleration of the oxygen ions in the center of these structures is interpreted as the integrated energization by these waves along the channels.Also observed within the channels are upward parallel electric fields,a key characteristic of kinetic Alfvén waves,which may contribute not only to lifting the ions but also to precipitating aurora electrons that might initiate ion upflow in the ionosphere below.Statistics on five-year observations of Cluster show that the channels typically form during geomagnetic perturbations,particularly when solar-wind dynamic pressure is high or highly fluctuated.Near the open-closed field line boundary,the stronger the wave power,the higher the upward oxygen flux and the higher the beam energy,indicating that these waves provide a simple but efficient way to drive oxygen upflows.

Ionospheric Investigations Conducted by Chinese Mainland Scientists in 2020-2021

In this report,we outline works done by scientists from the Mainland of China on various ionospheric topics after the release of the National Report of China in 2020 on ionospheric researchto the Committee on Space Research(COSPAR).More than 170 papers were published in 2020-2021.The current report covers the following topics:ionospheric space weather,ionospheric structures and climatology,ionospheric dynamics and couplings,ionospheric irregularity and scintillation,modeling and data assimilation,and ionosphere and sounding techniques.Planetary ionospheres are included for the first time.

Exploring the universe and protecting the Earth:Young Chinese scientists in action

The 5th Youth Scientist Forum of Planetary Science(YSFPS)took place from March 25 to 29,2023,in Sanya,a picturesque coastal city in the Hainan Province of southern China.This forum,one of China’s largest gatherings of its kind,experienced over 1,000 participants from domestic universities and research institutes discussing advancements in a variety of topics,including the surface,atmosphere,interior,core of planets,exoplanet exploration,asteroids,and comets(as shown in Figure 1A).One of the international hot topics in this meeting was lunar science research.With the return of lunar samples from the Chang’e-5 mission,scientists have immediately carried out various studies,forming new understandings about the moon’s evolution and raising new questions.