Study for material cycle with cosmogenic nuclides as tracers

1.对于太平洋和南极海的海洋表层：(1)^7Be浓度的深度剖面与水温剖面相似。在夏季，它们从地表开始减少，并在100米左右达到零。冬季在0 ~ 100m范围内保持恒定，超过100m后迅速下降。(2) ^<10>的Be浓度随深度的增加呈恒定或轻微的增加趋势。(3) ^7Be浓度的纬向分布与大气相似。最小值和最大值分别为5-10和20-40个原子cm^<-3>。(4) ^<10>Be浓度在南半球的纬向分布与在大气中的纬向分布相似。最小值和最大值分别为300-500和1500个原子cm^<-3>。铍-10在赤道地区和北半球的浓度几乎稳定在500 ~ 900个原子cm^<-3>.2范围内。在东京和八条岛，大气中^7Be和^<10>Be的浓度以及同位素比值^<10>Be/^7Be全年基本一致。东京和八条岛的同位素比值分别为1.81和1.75，高于海洋空气的1.5。用Al含量和Be/Al ^<10>对土壤再悬浮进行校正是拟合这些比值的有效方法。在东京和八条岛观测到雨水中^<10>的Be浓度估算的^<10>的地表Be通量的不同季节变化。北太平洋西部沉积物的Th年龄和Be浓度在20°N和40°N时分别为0.018-0.037和0.10-0.15原子cm^<-2> s^<-1>，估算出铍-10在海底的通量。前者值与海面通量基本一致，后者值比前者高3 ~ 4倍。这意味着^<10>的沉积物通量取决于沉积速率。

1.For the ocean surface layer of the Pacific Ocean and Antarctic Sea : (1)Depth profiles of ^7Be concentration were similar to water temperature profiles. In summer, they decrease from the surface and reach to zero around 100m. In winter, they keep constant value from 0 to 100m and decrease rapidly beyond this depth. (2)Depth profiles of ^<10>Be concentration showed constant or slight increase with increasing depth. (3)Latitudinal distribution of ^7Be concentration was similar to that in the atmosphere. The minimum and maximum were 5-10 and 20-40 atoms cm^<-3>, respectively. (4)Latitudinal distribution of ^<10>Be concentration in the southern hemisphere was similar to that in the atmosphere. The minimum and maximum were 300-500 and 1500 atoms cm^<-3>, respectively. Beryllium-10 concentrations in the equatorial region and northern hemisphere were almost constant within 500 to 900 atoms cm^<-3>.2.Atmospheric concentrations for ^7Be and ^<10>Be and isotopic ratio ^<10>Be/^7Be in Tokyo and Hachijo Island were similar to each other all through the year. The isotopic ratios 1.81 for Tokyo and 1.75 for Hachijo Island were higher than 1.5 for marine air. Correction for resuspension of soil with Al content and ^<10>Be/Al were effective to fit these ratios. Different seasonal variations of ^<10>Be flux to the land surface estimated from ^<10>Be concentration in rain were observed in Tokyo and Hachijo Island.3.Berylium-10 fluxes across sea floor estimated from excess ^<230>Th age and ^<10>Be concentration for sediments in the Western North Pacific were 0.018-0.037 and 0.10-0.15 atoms cm^<-2> s^<-1> for 20 and 40°N, respectively. The former values agree with the flux across the sea surface, but the latter values were 3 to 4 times higher than that. This imply that ^<10>Be flux to the sediment depend on the sedimentation rate.