中国首颗综合性太阳探测卫星

作为中国首颗综合性太阳探测卫星的先进天基太阳天文台(Advanced Space-based Solar Observatory, ASO-S)于北京时间2022年10月9日7时43分在酒泉卫星发射中心成功发射. 扼要介绍ASO-S卫星提出的背景、卫星的研制历程、科学目标、载荷构成、任务总体以及卫星研制的组织架构, 并对卫星的运行和科学产出略作展望.     

紫外辐射增强对菠菜种子萌发及出苗的影响

研究了紫外辐射（UA－B）增强对圆叶和尖叶菠菜种子萌发出苗的影响，结果表明，UV－B辐射增强将显著降低圆叶菠菜种子的出牙率和出苗率，延缓发牙进程，出苗速度，影响幼长势，而对尖叶菠菜的影响较小，增强UV－B辐射还能有效抑制菠菜种子发牙时因病菌感染而发生的霉变，并减少幼苗期病虫害的蔓延和发展。     

Spectral dependence on the correction factor of erythemal UV for cloud,aerosol, total ozone,and surface properties: A modeling study

Radiative transfer model simulations were used to investigate the erythemal ultraviolet(EUV) correction factors by separating the UV-A and UV-B spectral ranges. The correction factor was defined as the ratio of EUV caused by changing the amounts and characteristics of the extinction and scattering materials. The EUV correction factors(CFEUV) for UV-A[CFEUV(A)] and UV-B [CFEUV(B)] were affected by changes in the total ozone, optical depths of aerosol and cloud, and the solar zenith angle. The differences between CFEUV(A) and CFEUV(B) were also estimated as a function of solar zenith angle, the optical depths of aerosol and cloud, and total ozone. The differences between CFEUV(A) and CFEUV(B) ranged from-5.0% to 25.0% for aerosols, and from-9.5% to 2.0% for clouds in all simulations for different solar zenith angles and optical depths of aerosol and cloud. The rate of decline of CFEUV per unit optical depth between UV-A and UV-B differed by up to 20% for the same aerosol and cloud conditions. For total ozone, the variation in CFEUV(A) was negligible compared with that in CFEUV(B) because of the effective spectral range of the ozone absorption band. In addition, the sensitivity of the CFEUVs due to changes in surface conditions(i.e., surface albedo and surface altitude) was also estimated by using the model in this study. For changes in surface albedo, the sensitivity of the CFEUVs was 2.9%–4.1% per 0.1 albedo change,depending on the amount of aerosols or clouds. For changes in surface altitude, the sensitivity of CFEUV(B) was twice that of CFEUV(A), because the Rayleigh optical depth increased significantly at shorter wavelengths.     

What SDO tells us about structure and evolution of coronal bright points

Using magnetograms and coronal images from two instruments on board the Solar Dynamics Observatory (SDO), we study structure and evolution of a limited number of coronal bright points (CBPs). Our results show that the relation between CBPs and their magnetic footpoints is not simple. In some cases, CBP may appear as a bright portion of a larger loop (with clearly identifiable footpoints), and in some cases, an isolated CBP may develop between magnetic poles, which might not be the closest ones to each other or which might not be involved in the magnetic flux cancellation. We suggest that the magnetic connectivity responsible for formation of isolated coronal bright points is governed by the orientation of the large‐scale magnetic field. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)