相关实验视频
Updated: Jul 19, 2025

08:20
In Situ Soil Moisture Sensors in Undisturbed Soils
Published on: November 18, 2022
6.3K
在非洲之角逆转的全新纪温度-湿度关系
A J Baxter1, D Verschuren2, F Peterse3
1Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands. A.J.Baxter@uu.nl.
Nature
|August 9, 2023
概括
气候变化可能会导致非洲之角的干旱. 过去的数据显示温度和湿度的关系发生了变化,表明随着变暖,蒸发比降水增加.
科学领域:
- 古气候学
- 气候模型
- 水文学
背景情况:
- 人为气候变化影响全球水文循环,特别是在依赖季风降雨的热带地区.
- 近几十年来, 非洲之角的干旱情况有所增加, 与气候模型预测气温上升带来的降雨量增加相反.
- 气候变化的"干燥变干湿"模式需要在广泛的温度范围内进行测试.
研究的目的:
- 在过去的7万5千年里, 研究非洲最东部的水气候与温度关系的稳定性.
- 使用古气候数据测试"干燥变干燥,潮湿变潮湿"的模式.
- 了解过去的气候转折点及其对该地区未来气候变化的影响.
主要方法:
- 查拉湖 (肯尼亚和坦桑尼亚) 沉积物记录中的有机地化学气候代理数据的分析.
- 在过去的7.5万年里,水气候和温度的变化重建.
- 古气候数据与气候模型预测的比较.
主要成果:
- 实际湿度和温度之间的关系发生在全新纪 (大约11700年前) 开始时.
- 在最后一个冰河时期,较高的温度与增加的湿度相关;这种关系在全新纪开始时变得负面.
- 当大气中的二氧化碳超过250ppm,温度接近现代值时,
结论:
- 持续的人为变暖可能会导致非洲之角的干旱.
- 这项研究突出了热带水文循环中的一个关键转折点,
- 要准确预测未来气候变化的影响,需要改进热带水循环过程的模拟.
相关概念视频
Global Climate Change
24.5K
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.
24.5K
What is Climate?
18.6K
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.
18.6K
Isothermal Processes
3.7K
A thermodynamic process that occurs at constant temperature is called an isothermal process. Heat slowly flows into the system or out of the system to maintain thermal equilibrium. Processes involving phase changes like water evaporation into steam or freezing water into ice at a constant temperature are examples of Isothermal Processes.
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
3.7K
Thermosensation
30.5K
Peripheral thermosensation is the perception of external temperature. A change in temperature (on the surface of the skin and other tissues) is detected by a family of temperature-sensitive ion channels called Transient Receptor Potential, or TRP, receptors. These receptors are located on free nerve endings. Those detecting cold temperatures are closer to the surface of the skin than the nerve endings detecting warmth. These thermoTRP channels, while temperature selective, have relatively...
30.5K
Responses to Drought and Flooding
10.7K
Water plays a significant role in the life cycle of plants. However, insufficient or excess of water can be detrimental and pose a serious threat to plants.
10.7K
Temperature Dependent Deformation
170
In a nonhomogeneous rod made up of steel and brass, restrained at both ends and subjected to a temperature change, several steps are involved in calculating the stress and compressive load. Due to the problem's static indeterminacy, one end support is disconnected, allowing the rod to experience the temperature change freely. Next, an unknown force is applied at the free end, triggering deformations in the rod's steel and brass portions. These deformations are then calculated and added...
170

