Reconciling Models and Observations of Aerosol Indirect Effects: A 2004 Field Study in the Northeastern United States

气溶胶对云的影响（气溶胶间接效应）对辐射转移和气候强迫具有至关重要的相关性。人们对气溶胶的间接影响仍然知之甚少，而产生准确参数化和适当约束分析模型所需的高质量实验现场数据的严重缺乏加剧了这一点。该项目涉及海军跨学科遥控飞机研究中心办公室（ONR/CIRPAS）双水獭研究飞机的一系列现场实验（由ONR确认的校外资助），作为洲际运输和化学转化（ITCT）项目的一部分，于2004年夏季在美国东北部进行。加州理工学院（CalTech）小组将从“双水獭”收集各种气象、气溶胶微物理和化学数据，然后进行详细分析和三维辐射传输建模。该项目的最终目标是进行一项强有力的封闭研究，将辐射收支中的测量项与气溶胶和云性质对这些项的预测进行比较。考虑到涉及低空云的更高级的气溶胶-云相互作用参数化，将导致在一般环流模式框架下在各种尺度上对气溶胶-云辐射过程进行更有代表性的模拟。这项研究的结果将为我们对云和气候的理解提供新的数据和改进的见解，减少目前与量化当前和预测未来气候变化有关的巨大不确定性。更广泛的教育影响包括支持加州理工学院的一名博士后学者和两名研究生。通过与佐治亚理工学院的分包合同，将现场数据整合到一般环流模型气溶胶-云相互作用模块中，将支持另外一名研究生。

The effect of aerosols on clouds (aerosol indirect effect) has critically important relevance to radiative transfer and climate forcing. The aerosol indirect effect is still poorly understood, this aggravated by a severe paucity of high quality experimental field data required to produce accurate parameterizations and properly constrain analytical models. This project involves a series of field experiments on the Office of Naval Research Center for Interdisciplinary Remotely-Piloted Aircraft Studies (ONR/CIRPAS) Twin Otter research aircraft (with extramural funding from ONR confirmed) as part of the Intercontinental Transport and Chemical Transformation (ITCT) project during summer 2004 over the Northeastern United States. The California Institute of Technology (CalTech) group will collect a variety of meteorological, aerosol microphysical and chemical data from the Twin Otter and follow with detailed analyses and three-dimensional radiative transfer modeling. The ultimate goal of this project is a robust closure study comparing measured terms in the radiation budget to predictions of those terms from aerosol and cloud properties. Taking into account more advanced aerosol-cloud interaction parameterizations involving low-altitude clouds will lead to more representative modeling of aerosol-cloud-radiation processes on a variety of scales under a general circulation model framework. Results from this study will provide new data and improved insight to our understanding of clouds and climate, reducing present large uncertainties related to quantifying current and predicting future climate change. Broader educational impacts include support for one postdoctoral scholar and two graduate students at CalTech. Through a subcontract to Georgia Institute of Technology to incorporate field data into a general circulation model aerosol-cloud interaction module an additional graduate student will be supported.