HBCU-Excellence in Research: Vertical Profiles of Aerosols and Their Radiative Impacts

这项研究将寻求提高对气溶胶对气候变化和空气污染影响的认识；这对健康和社会都有影响。此外，传统黑人学院和大学（HBCU）的STEM（科学、技术、工程和数学）本科生将获得各种教育、实地实验和研究机会，作为课后研究经验。该项目还为HBCU的一名研究生和一名博士后提供支持和培训。此外，在本科和研究生的地球科学课程中，将有大量的机会将气溶胶辐射强迫和遥感作为真实的例子来介绍，以帮助学生提高他们的研究技术，并发展他们的论文和论文主题。气溶胶通过反射太阳辐射对气候系统产生降温作用。同时，一些气溶胶，如黑碳，可以吸收太阳辐射，在此过程中使地表冷却，但使大气变暖。气溶胶对辐射、温度剖面的这些影响，以及气溶胶作为云凝结核（CCN）的作用，通过气溶胶的直接辐射效应和对云性质和降水的间接辐射效应影响辐射平衡。要估计气溶胶对辐射强迫的影响，了解气溶胶垂直分布的信息是至关重要的，因为气溶胶的垂直分布对辐射强迫的标志有重大影响。本研究将开发一种新的气溶胶垂直分布检索算法，该算法可以利用广泛的ceilometer网络进行气溶胶垂直分布观测。然后研究了气溶胶垂直分布的变率及其对辐射强迫和升温速率剖面的影响。调查的气候区包括中纬度到热带的农村、城郊、城市、城市沙尘区和海洋区。本研究将探讨三个科学问题：(1)气溶胶在不同地区和季节的垂直分布特征是什么？(2)气溶胶垂直分布对辐射强迫有何影响？(3)不同地区和季节与气溶胶相关的升温速率曲线特征是什么？气溶胶对辐射强迫的直接和间接影响仍然是全球气候模式中最大的不确定性之一（IPCC, 2013），仅气溶胶垂直分布的不确定性就可以占到全球气溶胶直接影响不确定性的一半。为了量化气溶胶对辐射强迫的影响以及这些影响如何反过来影响气候和水文循环，需要气溶胶垂直分布的信息。该研究将通过一种新的检索算法来提高我们对气溶胶垂直分布的认识。它将改进气溶胶对辐射强迫的直接影响以及气溶胶-云-降水相互作用的间接影响的研究。它将有助于改进气溶胶参数化，进而改进空气质量预测、天气预报和气候模型。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The research will seek to improve understanding of aerosol's impacts on climate change and air pollution; this has implications for health as well as societal impacts. In addition, a variety of education, field experiment and research opportunities will be available for Historically Black Colleges and Universities (HBCU) STEM (Science, Technology, Engineering, and Mathematics) undergraduate students as after class research experiences. The project also provides support and training for a HBCU graduate student and a postdoctoral fellow. Moreover, there will be plenty of opportunities to introduce aerosol radiative forcing and remote sensing as real examples in undergraduate and graduate geoscience courses to help students to improve their research techniques and develop their theses and dissertation topics.Aerosols have cooling effect on climate system through reflecting solar radiation. At the same time, some aerosols e.g. black carbon, can absorb solar radiation, which cools the surface but warms the atmosphere in the process. These effects of aerosols on radiation, the temperature profile, along with the role of aerosols as cloud condensation nuclei (CCN), impact the radiative balance through the direct radiative effects of aerosols and indirect radiative effects on cloud properties and precipitation. To estimate aerosol effects on radiative forcing, knowing information about vertical distribution of aerosols is crucial since the vertical distribution of aerosols has a significant effect on the sign of radiative forcing. This research will develop a new aerosol vertical distribution retrieval algorithm which can take advantage of broad ceilometer networks on aerosol vertical distribution observations. Then the variability of aerosol vertical distributions and the impacts on radiative forcing and heating rate profile will be investigated. The investigated climate regions include areas of rural, suburban-urban, urban, urban-dust and ocean areas from mid-latitude to tropics. This research will investigate three scientific questions: (1) What are the characteristics of aerosol vertical distributions at different regions and seasons? (2) what are impacts of the aerosol vertical distribution on radiative forcing? and (3) what are the characteristics of heating rate profile associated with aerosols at different regions and seasons?Aerosols direct and indirect effects on radiative forcing is still one of the largest uncertainties in global climate models (IPCC, 2013) and the uncertainty in the aerosol vertical distribution alone can contribute as much half of the uncertainties of the global aerosols direct effect. The information of aerosol vertical distribution is needed to quantify the effects of aerosols on radiative forcing and how these in turn influence climate and the hydrological cycle. This study will enhance our understanding of aerosol vertical distributions though a new retrieval algorithm. It will improve the study of aerosol direct effects on radiative forcing as well as the indirect effects due to aerosol-cloud-precipitation interaction. It will aid to improve aerosol parameterizations and then improve air quality prediction, weather forecast and climate models.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.