Temporal variation of 7Be concentrations in atmosphere for 8 y from 2000 at Yamagata, Japan: solar influence on the 7Be time series
Temporal variation of 7Be concentrations in atmosphere for 8 y from 2000 at Yamagata, Japan: solar influence on the 7Be time series
复制标题
DOI：
10.1016/j.jenvrad.2009.03.017
复制
发表时间：
2009-06-01
影响因子：
2.3
通讯作者：
Tokanai, Fuyuki
中科院分区：
文献类型：
--
作者：
Kikuchi, Satoshi;Sakurai, Hirohisa;Tokanai, Fuyuki
自 2000 年以来，我们一直在连续观测日本山形（北纬 38.25 度，东经 140.35 度）地表空气中 Be-7 的每日浓度。Be-7 浓度的年度分布表明了由于太阳调制而导致的银河宇宙线的变化。 8 年来，Be-7 浓度、宇宙中子和太阳黑子数量分别变化了 37.4%、12.2% 和 92.8%。降水对 Be-7 变异性的影响约为 5%。因此，年 Be-7 浓度主要随 Be-7 生产率的太阳调节而变化。根据 EXPACS 模拟中发现的生产率，观察到的变化表明 Be-7 来自高纬度地区的运输。每日 Be-7 浓度有两个显着的周期分量：19 天和 36 天。 36 d 分量暗示太阳自转与安静太阳活动下气团垂直输送之间的关系。 (C) 2009 Elsevier Ltd. 保留所有权利。
We have been continuously observing the daily Be-7 concentrations in surface air at Yamagata, Japan (38.25 degrees N, 140.35 degrees E) since 2000. The yearly profile of the Be-7 concentration indicates the variation in galactic cosmic rays owing to solar modulation. Over 8 y, the Be-7 concentration, cosmic neutrons, and number of sunspots varied by 37.4%, 12.2%, and 92.8%, respectively. The influence of precipitation on the Be-7 variability was approximately 5%. Hence, the yearly Be-7 concentration was mainly varied by the solar modulation of the Be-7 production rates. Based on the production rates found in an EXPACS simulation, the observed variability indicates Be-7 transport from high latitudes. The daily Be-7 concentrations have two significant periodic components of 19 d and 36 d. The 36-d component implies a relationship between the sun's rotation and the vertical transport of air masses under quiet solar activity. (C) 2009 Elsevier Ltd. All rights reserved.