加利福尼亚电流在冰川最大值期间的崩与陆地气候变化有关
T D Herbert1, J D Schuffert, D Andreasen
1Department of Geological Sciences, Brown University, Providence, RI 02912, USA.
概括
在过去的55万年里,加利福尼亚海岸的海面温度 (SST) 发生了显著波动. 冰川变暖表明加利福尼亚电流正在减弱,支持冰河时代的轨道强迫.
科学领域:
- 古海洋学是古海洋学.
- 海洋地质学海洋地质学
- 气候科学 气候科学
背景情况:
- 基不和指数为重建过去海面温度 (SST) 提供了一个代理值.
- 加利福尼亚电流系统在区域气候调节中起着至关重要的作用.
- 了解冰川 - 冰川间周期是理解长期气候动态的关键.
研究的目的:
- 在过去的55万年里,沿加利福尼亚边缘重建过去的海面温度 (SST).
- 调查SST变化,加利福尼亚电流动态和冰川周期之间的关系.
- 评估古气候记录的区域和全球适用性.
主要方法:
- 从海洋沉积物核心中分析基不和指数.
- 对花粉进行分析,以识别气候变化的植被变化.
- SST记录与古气候数据和轨道强迫机制的相关性.
主要成果:
- 重建的SSTs显示了超过55万年的大冰川-冰川间波动 (4-8°C).
- 峰值的冰河间时期与红木花粉相关,表明温带雨林的存在.
- 在加利福尼亚流域脱冰之前,SSTs在10,000-15,000年前变暖,这与弱化的电流和改变的风系统有关.
结论:
- 加利福尼亚边缘的冰川变暖是加利福尼亚电流减弱的区域信号.
- 魔鬼洞的石灰岩记录反映了区域,而不是全球的古气温.
- 这些发现支持轨道 (米兰科维奇) 冰河时代理论.
相关概念视频
What 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.
Global 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.
Precipitation and Co-precipitation
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
Maximum Power Flow and Line Loadability
The maximum power flow for lossy transmission lines is derived using ABCD parameters in phasor form. These parameters create a matrix relationship between the sending-end and receiving-end voltages and currents, allowing the determination of the receiving-end current. This relationship facilitates calculating the complex power delivered to the receiving end, from which real and reactive power components are derived.
Load-frequency control
Load-frequency control (LFC) is vital for maintaining power system stability, ensuring that frequency and power flows remain within acceptable limits during load changes. Turbine-governor control eliminates rotor accelerations and decelerations following load changes. However, a steady-state frequency error persists when the change in the turbine-governor reference setting is zero. In an interconnected power system, each area agrees to export or import a scheduled amount of power through...
Frost Action on Concrete
Concrete structures in cold climates, such as those along roadsides, can retain moisture. This moisture makes them susceptible to frost-related damage when temperatures fall below freezing. Adding moisture worsens the damage during temperature fluctuations, leading to repeated freezing and thawing. De-icing salts, spread over these structures to melt ice, add to the freeze-thaw cycle, and draw even more moisture into the concrete.
This freeze-thaw cycle primarily causes surface scaling, where...
This freeze-thaw cycle primarily causes surface scaling, where...


