黔中气溶胶传输的~210Pb和~7Be示踪: Ⅰ.周时间尺度的解释
Pb and7Be as Tracers for Aerosol Transfers at Center Guizhou, China:Ⅰ.The Explanation by W eekly Interval
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文摘
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认识环境核素在不同地域空气中的浓度分布和沉降到地表环境的通量对气溶胶污染物全球扩散模型的建立和验证、沉积过程示踪和沉积计年、流域侵蚀示踪参比,以及生态系统受天然辐照的评价等多个领域都是关键的依据。自2001年以来在贵阳观风山等地逐周连续采样,对近地面空气和降水中~210Pb和~7Be浓度的观测结果表明:①因气象条件变化,近地面空气~210Pb和~7Be周浓度具有2~6周变幅不等的短周期波动。~210Pb空气浓度在年内的总趋势呈现出受气温变化的总体影响和降水的短暂调控;而7Be空气浓度出现连续不断的峰—谷交替。②两核素在近地面空气周浓度的低值同步,~210Pb/7Be比率较高(≥0. 8),显示出海洋性贫~210Pb-~7Be气团的入侵影响;它们高的周浓度也同步耦合,比率较低(≤0. 7),显示出高层大气富~7Be气团的输入。③~210Pb和~7Be的周降水浓度及水—气分配系数在秋末~春季较高,而春末—秋季明显偏低。周降水浓度随同期空气浓度呈增高趋势,其季节分界分别为0. 2 Bq/L和1 Bq/L;而Kd值随同期空气浓度增大呈降低趋势。~210Pb和~7Be的降水沉降主要分布在每年的春夏季;周沉降量随同期降水量呈增大趋势,~7Be增大的斜率约为~210Pb的3倍;当近于零降水时,它们在降水中的初始比率约为2. 5。它们出现高或者较高的周降水沉降都伴随当周或邻周空气浓度的急剧下降;降水中~210Pb/7Be比率主要分布在 ≤0. 5,并与空气中~210Pb/~7Be比率基本同步,显示出两核素被降水清洗的效率基本相近。④2008年冰冻极端天气过程中,~210Pb-~7Be空气浓度同步低谷并存在气溶胶低浓度与高比活度耦合。⑤观风山7Be周空气浓度显示低纬度、较高海拔地区的预期水平;短周期波动反映强下沉气流和低海拔上升气团影响分别在观风山和瓦里关山的滞后性。 |
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其他语种文摘
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It′s essential tomeasure air concentrations and depositional fluxes of environmental radionuclides in different regions formodeling global contamination transfer and validation, tracing deposition process and dating, referencingwatershed erosion trace and assessing natural radiation of ecosystem. This study introduces the research background andmethods and explainsweekly variationsof~210Pb and~7Be concentrations in surface airand precipitation at M.t Guanfeng/Guiyang since 2001. The results indicate that~210Pb and~7Be concentrations in surface air fluctuate periodically at2~6 week interval because of themeteorological condition changes. The annual trend in 210Pb air concentration is overall influenced by air temperature variation and periodical rainfal.l7Be air concentration varies up and down regualarly. The synchronization of low concentrations forboth210Pb and7Be in surface air and high ratio (~210Pb/~7Be≥0. 8) indicate oceanic poor~210Pb-~7Be airmass invasion. The synchronization of high concentrations of~210Pb and~7Be in surface air and low ratio (~210Pb/~7Be≤0. 7) implies rich7Be airmass invasion from altostratus atmosphere. Weekly concentrationsof~210Pb and~7Be in precipitation and the Kdcoefficients are high in late Autumn to Spring, and low in late Spring to Autumn. Although~210Pb and~7Be concentrations vary seasonally, theirweekly concentrations in precipitation increase with that of air concentration. The~210Pb and~7Be weekly concentrations for seasonal division is about0. 2 Bq/L and 1 Bq/L, respectively. However, the K_dcoefficientdecreaseswhen~210Pb and~7Be air concentrations increase. Deposition of~210Pb and~7Bewith precipitationmainly take place in Spring and Summer; The weekly fallout of~210Pb and~7Be increaseswith increasing precipitation; the increase of~7Be is triple of thatof~210Pb and 2. 5when precipitation nears to zero. Theweekly-high falloutof~210Pb and ~7Bewith precipitation correspondswith the dramatic decrease of their air concentrationswithin or vicinalweeks. The ratio of~210Pb to~7Be in rainfall is overall≤0. 5 and varies synchronouslywith the ratio in surface air, indicating that the two radionuclides are cleaned by precipitation from air atclose speed. In the extreme freezing disaster in 2008, both~210Pb and~7Be air concentrationswere low and couplingwith coexist of low concentration of aerosol and high nuclides activities. Weekly concentration of 7Be in surface air at M.t Guanfeng demonstrates the anticipated concentration level in the low-latitude and high-elevation region; the short-term fluctuationsof~7Be concentration indicated the hysteresiswas influcenced by the strong air current submersion and the low-elevation airmass rising differently at M.t Guanfeng and M.t Waliguan. |
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来源
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地球科学进展
,2010,25(5):492-504 【核心库】
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关键词
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气溶胶传输
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~210Pb-~7Be
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周时间尺度
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观风山
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瓦里关山
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地址
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中国科学院地球化学研究所, 中国科学院环境地球化学国家重点实验室, 贵州, 贵阳, 550002
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中国气象科学研究院, 北京, 100081
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Environmental Measurements Laboratory,USA, USA, NY, 10014-7447
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ISRIC-World Soil Information, the Netherlands, Wageningen, 6700AJ
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贵州省气象局, 贵州, 贵阳, 550002
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中国大气本底基准观象台, 青海, 西宁, 810001
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语种
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中文 |
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文献类型
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研究性论文 |
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ISSN
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1001-8166 |
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学科
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大气科学(气象学) |
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基金
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国家自然科学基金
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中美国际合作项目“Tracing recentclimate and environmental changesbymeasuring lowlevel radionuclides in the Yunnan-Guizhou plateau, China“
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文献收藏号
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CSCD:3896244
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参考文献 共
46
共3页
|
|
1.
Wan G J. Radionuclides in ecological systems.
Perspectives in Ecology. A Glance from the ⅦInternational Congress of Ecology (INTECOL), Florence, Italy, 19-25, July, 1998,1999:369-379
|
被引
1
次
|
|
|
|
|
2.
万国江. 环境生态系统散落核素示踪研究新进展.
地球科学进展,2000,15(2):172-177
|
被引
13
次
|
|
|
|
|
3.
万国江. 地球化学环境界面研究.
地球科学信息,1987(3):11-14
|
被引
6
次
|
|
|
|
|
4.
Santschi P H. Radioisotopes in aquatic sciences.
EAWAG / News,1983(14/15):1-6
|
被引
1
次
|
|
|
|
|
5.
Krishnaswami S. Comparative study of 222Rn, 40Ar,39Arand37Ar leakage from rocks andminerals: Implications for the role of nanopores in gas transport through natural silicates.
Geochimica et Cosmochimica Acta,1988,52:655-658
|
被引
5
次
|
|
|
|
|
6.
D rr H. 222Rn flux and soil air concentration profiles in West-Germany. Soil222Rn as a tracer for gas transport in the unsaturated soil zone.
Tellus B,1990,42:20-28
|
被引
1
次
|
|
|
|
|
7.
Turekian K K. Geochemistry of atmospheric radon and radon products.
Annual Review of Earth and Planetary Sciences,1977,5:227-255
|
被引
13
次
|
|
|
|
|
8.
Gillette D A. Measurement of the aerosol size distribution and vertical fluxes of aerosols on land subjiect towind erosion.
Journal of Applied Meteorology,1972,11:977-987
|
被引
11
次
|
|
|
|
|
9.
Appleby P G. The calculation of 210Pb dates assuming a constant rate of supply of unsupported210Pb to the sediment.
Catena,1978,5:1-8
|
被引
105
次
|
|
|
|
|
10.
Graustein W C. The effects of forests and topography on the deposition of sub-micrometer aerosols measured by lead-210 and caesium-137 in soils.
Agricultural and Forest Meteorol,1989,47:199-220
|
被引
2
次
|
|
|
|
|
11.
KUeR (Kommission zur Uberwachung der Radioaktivitat ) Bericht.
25 jahre radioaktivitatuberwachung in der Schweiz,1982:1-46
|
被引
1
次
|
|
|
|
|
12.
Goldberg E D. Geochronologywith210Pb.
Symposium on radioactive dating,1963:121-131
|
被引
1
次
|
|
|
|
|
13.
Krishnaswamy S. Geochronology of lake sediments.
Earth Planetary Science Letters,1971,11:407-414
|
被引
39
次
|
|
|
|
|
14.
Koide M. Marine geochronology with 210Pb.
Earth Planetary Science Letters,1972,14:442-446
|
被引
19
次
|
|
|
|
|
15.
Robbins JA. Models and uncertainty in210Pb dating of sediments.
The XXV International Congress of Societas, International Congress of Societas, International Limnologiae,1992
|
被引
1
次
|
|
|
|
|
16.
Robbins JA. Models and uncertainty in210Pb dating of sediments.
The XXV International Congress of Societas, International Congress of Societas, International Limnologiae,1993:217-222
|
被引
1
次
|
|
|
|
|
17.
Lal D. Cosmic ray produced radioactivity on the Earth.
Handbuch der Physik,1967:551-612
|
被引
6
次
|
|
|
|
|
18.
Feely HW. Factors that cause seasonal variations in Beryllium-7 concentrations in surface air.
Journal of Environmental Radioactivity,1989,9(3):223-249
|
被引
11
次
|
|
|
|
|
19.
Holton J R. Stratospheretroposphere exchange.
Reviews of Geophysics,1995,33:403-439
|
被引
102
次
|
|
|
|
|
20.
Zanis P. Factors controlling beryllium-7 at Jungfraujoch in Switzerland.
Tellus B,1999,51(4):789-805
|
被引
7
次
|
|
|
|
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