Aerosol and Cloud Particle Sampling
Aerosol and Cloud Particle Sampling
复制标题
气溶胶和云颗粒采样
DOI：
10.1002/9783527653218.ch6
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
A. Korolev
中科院分区：
文献类型：
--
作者：
Krämer;C. Twohy;M. Hermann;A. Afchine;S. Dhaniyala;A. Korolev
气溶胶和云粒子的测量是重要的，以扩大我们的知识，它们的分布，性质和相互作用的垂直范围的大气。原则上，可以使用各种平台进行大气测量。从固定的系留气球（例如Siebert等人，2003年）到风筝（Baslet，詹森和Frehlich，1998年; Muschinski等人，2001年）和气球（Deshlet等人，2003年）等低速平台，再到高速飞机或火箭（Rapp等人，2010年）。虽然较高速度的飞机能够对大面积进行采样，但较慢速度的平台具有成本较低、空间采样分辨率较高以及平台造成的气流畸变较小的优势。对于马赫数大于0.3的气流，必须考虑空气压缩性的影响和空气温度的相关变化（蒸发和冷凝）。颗粒停止距离随空气速度线性增加，该距离对于确定颗粒在表面上的撞击或进气系统的抽吸效率与单位的偏差是重要的。因此，气溶胶和云粒子测量高速飞机是最容易受到采样文物。大多数关于气溶胶和云采样的有限文献都提到了飞机平台，因此，我们在这里也关注飞机。然而，所描述的大多数效应也与其他机载平台相关。大气研究飞机部署了各种各样的传感器来测量大气状态参数（温度、压力和高度）、气相成分和颗粒。对于所有这些测量，特别是气溶胶和云粒子的测量，最基本的是要有一个代表自由流大气环境的空气样本。然而，从飞机上进行适当的空气采样是一个挑战，因为进入采样入口或传感器的空气可能受到飞机本身或采样装置的影响（Wendisch等人，2004年）。飞机机身周围的空气运动不仅会影响气流的速度和方向，而且会影响各种大气成分的浓度，特别是颗粒物。
Airborne aerosol and cloud particle measurements are important to extend our knowledge of their distribution, properties, and interactions over the vertical extent of the atmosphere. In principle, a broad range of platforms can be used for atmospheric measurements. These range from fixed tethered balloons (Siebert et al. 2003, for example) slow-speed platforms such as kites (Baslet, Jensen, and Frehlich 1998; Muschinski et al. 2001) and balloons (Deshlet et al. 2003), to high-speed aircraft or rockets (Rapp et al. 2010). While the higher speed aircraft are capable of sampling large areas, the slower speed platforms have their advantages in lower costs, higher spatial sampling resolutions, and less airflow distortion by the platform. The effect of air compressibility and associated changes in the air temperature (evaporation and condensation) must be considered for air flows with Mach numbers larger than 0.3. The particle stopping distance, which is important for determining the impaction of particles onto a surface or the deviation of the aspiration efficiency of an inlet system from unity, increases linearly with the air velocity. Hence, aerosol and cloud particle measurements from high-speed aircraft are most susceptible to sampling artifacts. Most of the limited literature dealing with airborne aerosol and cloud sampling refer to aircraft platforms; consequently, we also focus here on aircraft. However, most of the described effects are of relevance for other airborne platforms too. Atmospheric research aircraft deploy a great variety of sensors to measure atmospheric state parameters (temperature, pressure, and altitude), gas-phase constituents, and particles. For all those measurements, especially for aerosol and cloud particles, it is fundamental to have an air sample representative of the free stream atmospheric environment. However, appropriate air sampling from aircraft is a challenge, because air entering a sampling inlet or sensor can be influenced by the aircraft itself or by the sampling device (Wendisch et al. 2004). Movement of air around the aircraft fuselage can affect not only the airflow speed and direction but also the concentrations of various atmospheric components, especially particles.