金星大气超级旋转OA

Venus,the planet closest to Earth,has a slowly retrograde rotation in the opposite direction to Earth's,and it has a dense atmosphere that exhibits rapid westward motion.At the cloud top,around 65-70 km in altitude,zonal wind speeds reach up to 100 m/s—about 50-60 times faster than the surface rotation.This striking and enigmatic phenomenon is known as atmospheric superrotation.Since the 1960s,the spatiotemporal characteris-tics and angular momentum balance mechanisms of superrotation have remained one of the central challenges in planetary atmospheric dynamics,with sustained investigation for over six decades.This review summarizes the his-torical development of superrotation studies and highlights recent advances.In terms of the vertical structure,su-perrotation intensifies from the surface upward,peaking near the cloud top,then gradually weakens toward the mesopause at around 110 km,where the circulation is dominated by the diurnal cycle.In the latitudinal distribution,the cloud-top winds maintain nearly constant at its maximum values between 50°N and 50°S before decreasing to-ward the poles.Superrotation is generally understood to be maintained by angular momentum transport through the combined effects of atmospheric circulation and large-scale eddies(such as tides and planetary waves).Recent ob-servations and modeling results indicate that thermal tides primarily drive eddy contributions at the cloud top.In contrast,those in the middle and lower cloud layers(50-60 km)are mainly controlled by planetary waves.Further-more,long-term observations have revealed multiple timescales of variability in superrotation,ranging from a few days to several hundred days,and possibly up to～12 years linked to the solar cycle.State-of-the-art modeling stud-ies suggest that the dynamic balance of angular momentum transport between planetary waves and the general cir-culation largely regulates the quasi-200-day variability in the cloud region.Overall,research on superrotation has been shifting from a focus on its basic maintenance mechanisms to its spatiotemporal variability,and from large-scale processes to smaller-scale phenomena such as gravity waves.With advances in numerical models and future observational missions,a more comprehensive understanding of the origin and evolution of Venusian atmospheric superrotation within a climatic framework is anticipated.