DOI: 10.1016/j.epsl.2020.116530
论文题名: The depositional flux of meteoric cosmogenic 10Be from modeling and observation
作者: Deng K. ; Wittmann H. ; von Blanckenburg F.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 550 语种: 英语
中文关键词: cosmogenic nuclides
; Earth surface processes
; general circulation model (GCM)
; geochronology
; meteoric 10Be
; production rates
英文关键词: Condensation
; Deposition
; Earth atmosphere
; Soils
; Earth surface process
; General circulation model
; Long-distance transport
; Measurement time intervals
; Model and observation
; Precipitation events
; Precipitation rates
; Production function
; Soil surveys
; aerosol
; atmospheric deposition
; beryllium isotope
; cosmogenic radionuclide
; flux measurement
; general circulation model
; long range transport
; precipitation (climatology)
; soil profile
; water vapor
英文摘要: Meteoric cosmogenic 10Be is a powerful tracer to quantify dates and rates of Earth surface processes over timescales of 103-105 yrs. A prerequisite for its applications is knowledge of the flux at which 10Be, produced in the atmosphere, is delivered to the Earth surface. Four entirely independent approaches are available to quantify this flux: 1) General Circulation Models (GCM) combined with 10Be production functions and aerosol dynamics; 2) 10Be in precipitation collections; 3) 10Be inventories in dated soil profiles; 4) riverine 10Be exported in solid and dissolved forms. We compiled and reprocessed published globally distributed 10Be flux data from each of these methods and compared them with each other after normalization to a common atmospheric production rate. Based on precipitation records, we propose a simple framework to discriminate between two delivery effects on 10Be fluxes. In the additive effect water vapor and 10Be are continuously accumulating during long-distance transport, leading to an increase in 10Be flux with precipitation rate. In the dilution effect, the 10Be flux is delivered from proximal vapor sources, limited by the rate of 10Be introduction from the stratosphere and independent of precipitation rate. Both effects are mostly present in combination, and the relative weight of either effect depends on vapor condensation rate and on the ratio of vapor condensation area to precipitation area. A comparison between precipitation-derived fluxes and GCM-derived fluxes shows that half of the precipitation estimates are >2 times greater than GCM-derived fluxes. By comparison, soil- and GCM-derived fluxes agree within a factor of 2 for more than half (∼57%) of the dataset, and the remaining soil estimates (∼43%) are much lower than GCM-derived fluxes. 71% of 10Be flux estimates from riverine export using 10Be (meteoric)/9Be ratios also agree with GCM-derived fluxes within a factor of 2. We explain the precipitation-derived fluxes that commonly exceed all other estimates by short-term stochasticity in precipitation events that might introduce a measurement time-interval bias towards higher fluxes. This bias is not present over longer-term (103-105 yrs) flux estimates like those from soil profiles. Soil-derived fluxes might still present an underestimation when retention of 10Be in soil is incomplete. We recommend producing more 10Be depositional flux data from soil inventories with full Be retention, as these generate in our view the most relevant estimates for applications of meteoric 10Be on millennial-scale Earth surface processes. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164939
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: GFZ German Research Centre for Geosciences, Earth Surface Geochemistry, Telegrafenberg, Potsdam, 14473, Germany; State Key Laboratory of Marine Geology, Tongji University, Shanghai, 200092, China; Institute of Geological Sciences, Freie Universität Berlin, Berlin, 12249, Germany
Recommended Citation:
Deng K.,Wittmann H.,von Blanckenburg F.. The depositional flux of meteoric cosmogenic 10Be from modeling and observation[J]. Earth and Planetary Science Letters,2020-01-01,550