Analyses of Kwajalein Experiment (KWAJEX) and Southern African Regional Science Initiative (SAFARI-2000) Data

该奖项支持分析华盛顿大学云和气溶胶研究小组在两个实地项目中使用其Convair-580研究飞机收集的数据：1999年在马绍尔群岛的夸贾林实验(KWAJEX)和2000年夏末在南部非洲的南部非洲区域科学倡议(SAFARI 2000)。在这些实验中，飞机配备了测量云微物理特征、痕量气体浓度以及气溶胶粒子的大小、形状、组成和光学性质的设备。KWAJEX主要侧重于研究热带对流云中的云和降水过程。正在进行的研究包括(1)调查一项意想不到的观测结果，即水滴似乎在相对温暖的温度(高于-10摄氏度)下破碎，并产生大量冰碎片，作为二次冰核的来源；(2)分析通过液态云滴的碰撞和合并而非常迅速地产生雨的证据；(3)调查最初形成雨的极窄云丝(直径数十米)的来源和性质。Safari的观测旨在记录南部非洲海岸外大西洋上空被污染的空气的化学和物理特性。这些数据非常适合于评估生物质燃烧产生的烟雾对大气化学以及对太阳和地面辐射传输的影响。一个目标是通过烟雾对大气辐射平衡的直接影响和间接影响来确定烟雾对气候的影响，间接影响是由吸入烟雾的云的微观结构和光学特性的变化引起的。目前正在特别注意Safari提供的有关大气痕量气体的独特数据。测量了许多物种的排放率，并将用作化学运输模型的输入，以便与顺风向飞机的测量结果进行比较。一个目标是了解人为排放(气溶胶和气体)的演变，包括它们与云的相互作用，足够好地预测它们对辐射平衡的影响。

This award supports analysis of data collected by the Cloud and Aerosol Research Group (CARG) of the University of Washington, using its Convair-580 research aircraft, in two field projects: the Kwajalein Experiment (KWAJEX) in the Marshall Islands in 1999, and the Southern African Regional Science Initiative (SAFARI 2000) in Southern Africa in the late summer of 2000. In these experiments, the airplane was equipped for measuring cloud microphysical characteristics, the concentrations of trace gases, and the sizes, shapes, composition, and optical properties of aerosol particles. KWAJEX was focused primarily on investigating cloud and precipitation processes in tropical convective clouds. Studies under way include (1) investigating the unexpected observation that drops appear to shatter at relatively warm temperatures (warmer than -10C) and produce large numbers of ice splinters as a source of secondary ice nuclei; (2) analyzing the evidence for very rapid rain production by the collision and coalescence of liquid cloud droplets; (3) investigating the origin and properties of the extremely narrow cloud filaments (tens of meters across) in which the rain initially forms. The SAFARI observations were designed to document the chemical and physical properties of the pall of polluted air over the Atlantic Ocean off the coast of Southern Africa. The data are well suited for evaluating the effects of the smoke from biomass burning on atmospheric chemistry and on the transfer of solar and terrestrial radiation. A goal is to determine the climatic impact of the smoke through both its direct effect on the atmospheric radiative balance and its indirect effect, caused by changes in the microstructure and hence the optical characteristics of clouds that ingest the smoke. Special attention is being given to the unique data from SAFARI on atmospheric trace gases. The rates of emission for many species were measured, and will be used as inputs for chemical transport models for comparison with the downwind aircraft measurements. A goal is to understand the evolution of anthropogenic emissions (aerosols and gases), including their interaction with clouds, well enough to predict their effect on the radiative balance.