熱帯大西洋の10年間の変動は,外からの圧力によって支配されている
Chengfei He1, Amy C Clement2, Sydney M Kramer3
1Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, FL, USA. cxh1079@miami.edu.
Nature
|September 13, 2023
まとめ
熱帯大西洋の海面温度 (SST) グラデーションは,人間の排出と火山のエアロゾールによって引き起こされ,ハリケーン活動とサヘルの降雨に大きく影響します. この重要な気候関連性は モデルバイアスが修正されたときにより明確になります
科学分野:
- 気候科学
- 大気科学
- 海洋学
背景:
- 熱帯大西洋の気候は,海面温度 (SST),サヘルの降雨量,ハリケーン活動における多十年間の変動を示しています.
- これらの相互接続した気候システムの物理的起源は,モデルと観測の不確実性のために議論されている.
研究 の 目的:
- 熱帯大西洋 SSTにおける赤道横断グラデントが,大西洋のハリケーン形成とサヘルの降雨の原動力として果たす役割を調査する.
- これらの気候関係のシミュレーションにおけるCMIP6地球システムモデルのパフォーマンスを評価する.
主な方法:
- 歴史的な気候データとCMIP6地球システムモデルの大きなアンサンブルの分析.
- 北半球と南半球の温暖化傾向と関連する大気変化のシミュレーションにおけるモデルバイアスの特定と修正.
- 修正されたSSTグラデーションと気候の影響の相関分析
主要な成果:
- 放射性強迫 (人為的排出,火山噴出物) によって影響される赤道横断の熱帯大西洋SSTグラデントは,ハリケーン活動とサヘルの降雨を決定する重要な要因です.
- CMIP6モデルは北半球の温暖化傾向を過大評価し,SSTと気候の関係を隠しています.
- モデルバイアスを修正すると,特に1950年以降,SSTのグラデーションと気候の影響の間の強い相関が明らかになる.
結論:
- 熱帯大西洋 SST グラデントは,より広い北大西洋 SST よりも熱帯気候の影響の重要な原動力です.
- 人為的な排出と火山活動を含む放射能強制は,大西洋のハリケーン活動とサヘルの降雨変動を予測することができます.
- 将来の予測の正確さは,シグナル対ノイズパラドックスと将来の気候強制力の不確実性によって制限されています.
関連する概念動画
01:26General External Flow Characteristics
226
The study of external flow is essential for creating structures and objects that interact efficiently and safely with moving fluids, such as air or water. When a body is immersed in a flowing fluid, it experiences two primary forces: drag, which opposes motion along the flow direction, and lift, which acts perpendicular to the flow. The shape, size, and orientation of the object influence these forces.Streamlined and Blunt Bodies in External FlowObjects in fluid flow are classified as...
226
01:12Internal and External Forces
13.1K
Newton's first law states that a net external force causes a change in motion. External forces act on an object or system, originating outside of the object or system. In contrast, internal forces originate inside the system of interest and do not lead to any acceleration. In simpler words, internal forces are forces that act on one part of an object and are exerted by another part of the same object. External forces are forces that act on an object due to some other object. Therefore, when...
13.1K
01:50Global 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
01:12Precipitation Processes
484
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...
484
01:23Coriolis Force
3.5K
An accelerating particle experiences a force equal to the mass multiplied by the acceleration in an inertial frame of reference. Consider a particle in a non-inertial frame of reference, such as a sliding ball on a rotating table. The acceleration of the ball in this rotating reference frame is different than in the intertial frame, which modifies its equation of motion. The fictitious forces acting additionally on a rotating frame of reference alter Newton's Second Law expression.
3.5K
01:16What 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