支持挪威核准备的海洋和大气运输建模:最近的成就和剩余的挑战
Magne Simonsen1, Erik Berge1, Heiko Klein1
1Norwegian Meteorological Institute, Postboks 43 Blindern, NO-0313 Oslo, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway.
The Science of the total environment
|January 9, 2025
概括
数字运输模型预测了核应急反应的放射性核素分散. 大气和海洋模型的改进,特别是不确定性量化和动态特异化,提高了预测准确性和决策支持.
科学领域:
- 环境科学 环境科学
- 核安全问题 核安全问题
- 计算机建模 计算建模
背景情况:
- 数字运输模型对于核应急决策至关重要,它提供了快速的放射性核素分散预测.
- 了解空气和海洋中的放射性核素运输涉及复杂的物理化学过程和固有的不确定性.
- 不确定性的来源包括释放描述,驾驶数据,过程描述和模型参数.
研究的目的:
- 综合了在CERAD计划下开发的大气和海洋放射性核素运输模型的关键改进.
- 解决模型估计中的不确定性,并增强环境运输的预测能力.
- 评估模型升级对核紧急情况决策支持系统的影响.
主要方法:
- 在大气分散估计中包含不确定性量化.
- 适应大气模型的高分辨率强制数据和整体预测.
- 为海洋放射性核素运输实施动态物种化和参数化.
- 分析大气组合预测和海洋运输受环境因素影响的案例研究.
主要成果:
- 大气模型使用集体平均值比单个决定性运行显示了改进的预测.
- 海洋模型展示了放射性核素分布中的动态物种化,粒子大小和参数化的意义.
- 模型开发提供了对放射性核素运输的更深入的见解,这些运输受到环境变化的影响,例如河流流失.
结论:
- 最近大气和海洋运输模型的进步,特别是通过CERAD计划,显著提高了预测的准确性.
- 结合不确定性量化和动态流程,可以为核紧急情况提供更可靠的决策支持.
- 未来的工作应侧重于运营性海洋模型,基于集合的不确定性量化,并通过反向建模改进源识别.
相关概念视频
Primary Production
23.5K
The total amount of energy acquired by primary producers in an ecosystem is called gross primary production (GPP). However, of this energy, producers use some for metabolic processes, and some is lost as heat, decreasing the amount of energy available to the next trophic level. The remaining usable amount of energy is called the net primary productivity (NPP). In terrestrial ecosystems, NPP is driven by climate, while light penetration and nutrient availability drive NPP in aquatic ecosystems.
23.5K
Nuclear Stability
18.5K
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together...
To hold positively charged protons together...
18.5K
Nuclear Binding Energy
12.2K
The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect indicates a “loss” in mass of 4.0331 amu – 4.0026 amu = 0.0305 amu. The loss in mass accompanying the formation of an atom from protons, neutrons, and electrons is due to the conversion of that mass into energy that is evolved as the atom forms. The nuclear binding energy is the energy produced when the atoms’ nucleons...
12.2K
Nuclear Fission
9.5K
Many heavier elements with smaller binding energies per nucleon can decompose into more stable elements that have intermediate mass numbers and larger binding energies per nucleon—that is, mass numbers and binding energies per nucleon that are closer to the “peak” of the binding energy graph near 56. Sometimes neutrons are also produced. This decomposition of a large nucleus into smaller pieces is called fission. The breaking is rather random with the formation of a large...
9.5K
Nuclear Power
7.7K
Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons has six components: nuclear fuel consisting of fissionable material, a nuclear moderator, a neutron source, control rods, reactor coolant, and a shield and containment system.
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...
7.7K
Nuclear Fusion
17.9K
The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process called fusion. The principal source of energy in the sun is a net fusion reaction in which four hydrogen nuclei fuse and ultimately produce one helium nucleus and two positrons.
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
17.9K


