概括
与11年太阳周期相关的太阳紫外线流量变化,显著影响臭氧度和平流层温度趋势. 这项研究使用辐射-传递-光化学模拟验证了这些发现.
科学领域:
- 大气科学 大气科学
- 太阳物理 太阳物理
- 气候科学 气候科学
背景情况:
- 在20世纪60年代初至1976年间观察到平流层臭氧和温度的趋势.
- 大气变化的潜在驱动因素.
研究的目的:
- 调查太阳紫外线流动变化对臭氧和平流层温度的影响.
- 为了确定11年太阳周期对这些大气参数的影响程度.
主要方法:
- 开发和应用一个辐射-传递-光化学模型.
- 模拟由太阳紫外线流量的变化驱动的大气变化的模拟.
- 模型结果与已发表的观察数据进行比较.
主要成果:
- 模拟显示与公布的关于臭氧度和平流层温度的数据有很好的一致性.
- 与11年太阳周期相关的太阳紫外线流变性被确定为观察到的趋势的主要因素.
结论:
- 11年的太阳周期是臭氧和平流层温度变化的重要驱动因素.
- 采用的模型有效地捕捉了太阳活动和大气条件之间的关系.
相关概念视频
01:50Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
03:40Hess's Law
There are two ways to determine the amount of heat involved in a chemical change: measure it experimentally, or calculate it from other experimentally determined enthalpy changes. Some reactions are difficult, if not impossible, to investigate and make accurate measurements for experimentally. And even when a reaction is not hard to perform or measure, it is convenient to be able to determine the heat involved in a reaction without having to perform an experiment.
02:55Temperature Dependence on Reaction Rate
The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
02:28Effect of Temperature Change on Reaction Rate
The Arrhenius equation,
01:16What is Climate?
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
02:11Effects of Temperature on Free Energy
The spontaneity of a process depends upon the temperature of the system. Phase transitions, for example, will proceed spontaneously in one direction or the other depending upon the temperature of the substance in question. Likewise, some chemical reactions can also exhibit temperature-dependent spontaneities. To illustrate this concept, the equation relating free energy change to the enthalpy and entropy changes for the process is considered: