Tropospheric transport to Syowa Station, Antarctica : contribution from mid to low latitude

在南极Syowa站进行的大气观测包括测量气溶胶粒子的数量-尺寸分布(约5~5000 nm)、烟尘浓度和用于化学分析的尺寸分离的气溶胶样品的采集等。大气中的Rn和CO浓度也被测量为从中低纬度空气输送的示踪剂。除了在Syowa站的全年观测外，还利用一艘船(Shirase)和一架飞机(PC-6)进行了大气观测，以获得气溶胶的空间分布。烟尘和氡浓度的临时变化表明，冬季和春季与低压系统的迁移有关，气团从中纬度零星地输送过来。在有强风的暴风雪条件下，气溶胶浓度总是很高。静风条件下的气溶胶事件是冬季新发现的。从春末到夏末，多次观测到模径小于20 nm的气溶胶粒子。

Atmospheric observations in this study at Syowa Station, Antarctica include measurements of number-size distribution (ca.5 〜 5000 nm) of aerosol particles, soot concentrations, and collections of size-segregated aerosol samples for chemical analysis etc. Atmospheric Rn and CO concentrations were also measured as tracers of air transport from mid to low latitudes. In addition to year round observation at Syowa Station, atmospheric observations using a ship (Shirase) and an airplane (PC-6) were also conducted to obtain spatial distribution of aerosols.Temporal variations of soot and Rn concentrations imply sporadic transport of air masses from mid latitudes during winter and spring associated with migration of low pressure systems. Aerosol concentrations were always high during blizzard conditions with vigorous winds. Aerosol events under calm wind condition were newly found in winter. Aerosol particles having a mode diameter less than 20 nm were observed for several times from late spring to late summer.