热带安第斯冰川的700,000年
D T Rodbell1, R G Hatfield2, M B Abbott3
1Geoscience Department, Union College, Schenectady, NY, USA. rodbelld@union.edu.
Nature
|July 13, 2022
概括
安第斯山脉的热带冰川在70万年间紧密跟随了全球冰的变化. 区域气候变化影响了冰川的范围,揭示了半球间的气候联系.
科学领域:
- 古气候学
- 冰川学
- 气候变化
背景情况:
- 为了了解冰河时代的周期,需要很好的日期的热带冰川记录,而这些记录很少.
- 持续的古气候档案对于半球间冰川活动的比较至关重要.
- 现有的热带记录往往缺乏跨越多个冰川 - 间冰川周期所需的长期连续数据.
研究的目的:
- 建立一个连续的,独立日期的热带冰川古气候档案.
- 调查热带安第斯冰川的波动与全球冰的数量之间的关系超过70万年.
- 探索影响热带冰川的半球间气候远程连接.
主要方法:
- 在亚马逊最上层流域的朱宁湖的活塞芯分析.
- 沉积物核心的独立约会建立一个精确的时间框架.
- 使用沉积物学和地化学代理的过去冰川活动的重建.
主要成果:
- 朱宁湖的核心提供了第一次连续的,独立的日期记录热带冰川覆盖70万年.
- 热带安第斯冰川表现出明显的10万年周期,跟踪全球冰量变化.
- 冰川的扩张发生在20万到40万年前,与水文平衡和季风模式的改变有关.
- 在最后一个冰川周期中,千年规模的冰川变化与格陵兰岛的温度异常相关,这表明季风驱动的半球间联系.
结论:
- 热带冰川是全球冰量和气候动态的可靠指标.
- 区域水文和季风变化显著调节了热带冰川的行为.
- 证据表明,在整个冰川周期中,热带和格陵兰冰芯之间存在持续的半球间气候远程连接.
相关概念视频
Global Climate Change
24.7K
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.
24.7K
Isothermal Processes
3.9K
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...
3.9K
What is Climate?
18.8K
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.
18.8K
Precipitation Processes
576
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
576
Isochoric and Isobaric Processes
3.6K
A thermodynamic process that occurs at constant volume is called an isochoric process. According to the first law of thermodynamics, heat supplied or removed from the system is partially utilized to perform work and change the internal energy of the system. However, in an isochoric process, the volume remains constant. Hence, the work done by the system is zero. Therefore, the exchange of heat changes the internal energy of the system only.
Suppose 1000 g of water is heated from 40...
Suppose 1000 g of water is heated from 40...
3.6K
Speciation Rates
21.4K
Overview
21.4K


