Radon continuous observation on the sea surface atmosphere by using the high sensitive radon detector

2004年9月13日至9月17日，在日本海从门别到托特里的破冰船SHIRASE上使用高灵敏度氡探测器对大气氡进行了连续测量。2004年12月13日至2005年3月18日，从弗里曼特尔经SYOWA站到悉尼的南极海洋。氡的观测结果预计将有助于建立从其他大陆、南美洲和非洲到南极洲的大气远距离迁移模型。结果表明：（1）观测到的南大洋大气氡浓度最低本底水平0.02Bqm-^3与海洋大气氡通量0.01Rncm-^2s^的模拟结果相一致;（<-1>2）在南大洋观测到6次氡浓度快速增长事件（氡风暴）。2005年2月25日与SYOWA站和SHIRASE站的平行观测成功地进行了雷达风暴探测， ...更多信息 在离SYOWA 500公里的阿蒙森海湾近海。根据NOAA卫星照片，两个观测点位于低气压的前部。通过与观测资料和大气传输模式估算资料的对比分析，证实了这次辐射风暴是在一周内从南美洲向SOYWA站传输的。观测到达时间与模型评价时间一致，但氡浓度与观测值不同，SHIRASE为0.145Bqm^<-3>，SYOWA为0.085Bqm^<-3>，评价值为0.024Bqm^<-3>。该模型未能模拟SYOWA站的辐射风暴事件的振幅。这些高浓度事件可能是似顺时针的水平结构或层状垂直结构的结果。该模型在雷达风暴事件中的应用有待进一步改进。这些对南极海洋的氡观测结果将有助于大气远程传输模式的发展。

Continuous measurements of the atmospheric radon have been made in the ice breaker SHIRASE by the use of the high sensitive radon detector upon the Japan Sea from Monbetsu to Tottri(13 Sep.2004- 17 Sep.) and the Antarctic Ocean from Fremantle via SYOWA station to Sydney(13 Dec.2004 - 18 Mar.2005). The observation results of the radon will be expected to contribute for the development of the atmospheric long-range transport model to Antarctica from the other continents, South America and Africa. The results are summarized as follows.1) The observed minimum background level 0.02Bqm-^3 of the atmospheric radon concentration upon the Antarctic Ocean corresponds with the simulation results from the ocean atmospheric flux of radon 0.01Rncm-^2s^<-1>.2) The rapid increasing events of the radon concentration (radonic storm) were observed 6 events on the Antarctic Ocean. The radonic storm detection on 25-Feb 2005 was success to the parallel observation with the SYOWA station and SHIRASE, which w … More as shipped offshore Amundsen Gulf far 500km from SYOWA. Two observation points were located on the front of the depression from the NOAA satellite photographs. This radonic storm event turned out to be transport from the South America to SOYWA station with the one week by the comparison with the observation data and evaluated data of the Atmospheric transport model. The observation arrival time was coincident with the evaluation time of the model, but the radon concentrations were different with the observations, SHIRASE 0.145Bqm^<-3> and SYOWA 0.085Bqm^<-3> and evaluation 0.024Bqm^<-3>. The model failed to simulate the amplitudes of radonic storm events at SYOWA station. These high concentration events were possibly a result of filament-like horizontal structure or laminated vertical structure. The improvement of the model was expected for the radonic storm events. These radon observation results on the Antarctic Ocean will be contributed to the development of the atmospheric long-range transport model Less