熱帯の新粒子の形成による雲凝縮核の大きな源

Christina J Williamson^1,2, Agnieszka Kupc^3,4, Duncan Axisa^5,6

¹Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA. christina.williamson@noaa.gov.

Nature

|October 18, 2019

まとめ

熱帯上の熱帯圏における新粒子の形成 (NPF) は,雲凝縮核 (CCN) の重要なグローバルな源である. 地球の40%以上で起こっています

科学分野:

大気科学
気候科学
エアロゾール科学

背景:

雲の凝縮核 (CCN) は,雲の性質と地球の放射線バランスに影響を与えます.
自由なトロポスフィアの新粒子の形成 (NPF) は,特に遠隔地でのCCNの潜在的,まだ量化されていない源です.

研究の目的:

航空機の現地測定を用いて,NPFの発生に関する世界的な調査を実施する.
トロピカル上層トロポスフィアのNPFがCCNの生産に与える貢献を決定する.
全球モデルにおけるNPFとその後の粒子の増加を評価する.

主な方法:

エアロゾールのサイズ分布を空中で測定する.
熱帯コンベクト地域における垂直プロフィールの分析
総合的な評価のための化学物質輸送モデルとの統合

主要な成果:

太平洋と大西洋の熱帯コンベクティブ地域では,高い高度で強いNPFが観察されました.
NPFは地球表面の約40%をカバーする熱帯上層熱帯圏の持続的な地球規模帯を形成しています.
熱帯上層熱帯圏のNPFは,下層熱帯圏に影響を与える,世界的に重要なCCN源です.

結論:

熱帯圏上部のNPFは,以前は過小評価されていたCCNの主要な源です.
グローバルモデルでは,熱帯上層熱帯圏のNPFとCCNサイズへの粒子の成長の大きさを正確に捉えることができません.
この発見は,正確な放射能バランスの見積もりのために,気候モデルにおけるNPFプロセスの改善の必要性を強調しています.

さらに関連する動画

09:34

Extraction and Characterization of Surfactants from Atmospheric Aerosols

Published on: April 21, 2017

17.2K

09:46

Production and Measurement of Organic Particulate Matter in the Harvard Environmental Chamber

Published on: November 18, 2018

7.7K

関連する概念動画

01:12

Precipitation Processes

4.5K

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...

4.5K

01:16

Precipitate Formation and Particle Size Control

5.0K

In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...

5.0K

01:17

Precipitation and Co-precipitation

4.0K

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...

4.0K

03:11

Precipitation of Ions

29.7K

Predicting Precipitation
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:

29.7K

01:10

Types of Coprecipitation

4.8K

Coprecipitation is the contamination of a precipitate by otherwise soluble species and occurs via different processes. In colloidal precipitates, coprecipitation occurs via surface adsorption. For instance, barium sulfate has a primary layer of adsorbed barium ions and a secondary layer of nitrate counterions. This results in contamination of the precipitate by barium nitrate.
Sometimes, ions in a crystal lattice can undergo isomorphous replacement by inclusions of similar charge and size. For...

4.8K

02:39

Phase Transitions: Vaporization and Condensation

20.4K

The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...