宇宙と地上から観測された下層熱帯のHDO/H2O比率を制御するダイナミックなプロセス
Christian Frankenberg1, Kei Yoshimura, Thorsten Warneke
1SRON-Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, Netherlands. C.Frankenberg@sron.nl
まとめ
この研究は,サヘル地域における予期せぬ水の同位体季節性を明らかにし,気候モデルに挑戦しています. 高緯度分析は,大気動力学が降水同位体に対する温度効果を覆す可能性があることを示しています.
科学分野:
- 水文学 水文学とは
- 気候科学 気候科学
- 大気物理学 大気物理学
背景:
- 温度に対する水文循環の反応は,気候の再構築と予測に不可欠です.
- 水蒸気同位体 (HDO/H2O) の分布を理解することは,気候の研究の鍵です.
研究 の 目的:
- 宇宙のスペクトロスコピーを用いて水蒸気同位体の地球分布を調査する.
- サヘル内部の高いHDO/H2O季節性とその影響が大気循環モデルに及ぼす影響を分析する.
- 高緯度における同位体組成に対する温度対ダイナミックプロセスの影響を調べる.
主な方法:
- 宇宙の吸収スペクトロスコーピーを用いてデュテラート水/水 (HDO/H2O) の豊富な量の回収.
- 高緯度におけるデルタD (デウテリウム/水素比) の地上観測の分析.
- ダイナミックなプロセスと温度が同位体組成に与える影響を評価するためにモデル研究を利用する.
主要な成果:
- サヘル内部の地域で予想外にも高いHDO/H2Oの季節性が見られた.
- ハドリー循環の沈下分岐に強い同位体枯渇が確認された.
- 動的プロセスが,高緯度における降雨の同位体組成に対する温度効果を完全に補償できることを実証した.
結論:
- 一般的な循環モデルでは,ハドリー循環の減退分岐における同位体の枯渇を誤って表す可能性があります.
- 大気動態は重要な役割を果たし,特定の地域における降雨同位体に対する温度効果を潜在的に支配している.
関連する概念動画
The Water Cycle
The Earth’s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, the cycling of water is extremely important to ecosystem dynamics.
Hess's Law
There are two ways to determine the amount of heat involved in a chemical change: measure it experimentally, or calculate it from other experimentally determined enthalpy changes. Some reactions are difficult, if not impossible, to investigate and make accurate measurements for experimentally. And even when a reaction is not hard to perform or measure, it is convenient to be able to determine the heat involved in a reaction without having to perform an experiment.
Precipitation Processes
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...
Isochoric and Isobaric Processes
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 degrees...
Suppose 1000 g of water is heated from 40 degrees...
Variation 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...
Boundary Layer Characteristics
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...


