アラスカの亜北極圏におけるホロセンの気候の周期的変化と太陽による強制作用
Feng Sheng Hu1, Darrell Kaufman, Sumiko Yoneji
1Department of Plant Biology, University of Illinois, Urbana, IL 61801, USA. fshu@life.uiuc.edu
Science (New York, N.Y.)
|September 27, 2003
まとめ
アラスカのホロセンの気候は,太陽活動に関連した周期的な変動を示しました. 太陽光によるこれらの変化は北部の生態系に影響を及ぼし,北大西洋と北太平洋全域で同様の気候変動が起きていることを示唆している.
科学分野:
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 四次地質学 四次地質学
- 気候科学 気候科学
背景:
- ホロセンの気候の変動は,地球の気候システムを理解するために重要です.
- 高緯度地域は,地球規模の気候変動の敏感な指標である.
- 太陽活動が地域気候に及ぼす影響は,依然として活発な研究分野である.
研究 の 目的:
- アラスカ南西部におけるホロセンの気候と生態系の動態を調査する.
- 気候の変動の周期性とその太陽活動との相関を特定する.
- 北大西洋と北太平洋地域間のホロセンの気候変化を比較する.
主な方法:
- アラスカ南西部の湖の堆積物核の高解像度分析.
- 周期的な変動と周期性を特定するためのスペクトル分析.
- コスモゲンヌクリド (炭素14とベリリウム10) と北大西洋の漂流氷の時間系列との相関分析.
主要な成果:
- 湖の堆積物記録は,ホロセーン期における明確な周期的な気候と生態系の変化を明らかにしています.
- これらの変動は,太陽活動サイクルと一致する周期を示しています.
- アラスカの気候データ,コスモジェニックヌクリド記録,北大西洋の漂流氷のデータとの間に一貫性が見られた.
結論:
- 太陽光照射の変動は,北部の高緯度の環境におけるホロセンの気候と生態系に大きな影響を与えた.
- 亜極の北大西洋と北太平洋における百年規模の気候変動は,同期していた.
- 太陽・海洋・気候の関連が,これらの半球間の気候変化を同期させる上で重要な役割を果たした可能性が高い.
関連する概念動画
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.
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.
02:45Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
01:19Cyclic Processes And Isolated Systems
A thermodynamic system with zero heat exchange and work is an isolated system. For these systems, the internal energy remains constant.
In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state.
Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each path...
In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state.
Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each path...
01:18Variation of Atmospheric Pressure
Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
01:27Microbes and Climate Change
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...