Collaborative Research: Self-Aggregation of Moist Convection, Radiative-Convective Instability, and the Regulation of Tropical Climate

合作研究：湿对流的自聚集、辐射对流不稳定性以及热带气候的调节

• 批准号: 1418309
• 负责人: Marat Khairoutdinov
• 金额: $ 28.38万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-15 至 2020-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1418309&HistoricalAwards=false
• 关键词: Collaborative; Research; Self; Aggregation; Moist

Tropical showers and thunderstorms play an important role in the regulation of Earth's climate. One theory regarding tropical convection is that as sea surface temperatures warm, more clouds form and the atmosphere becomes drier. While the clouds reduce solar radiation from warming the surface, that effect is more than counteracted by a drier atmosphere allowing more outgoing radiation to pass. This could suggest that the tropical climate has a level of self-regulation. To study this idea, the researchers involved in this project have created an idealized computer model to address what they call the "self-aggregation" of convection. This is the tendency for clouds and thunderstorms to move together into clusters. This award will provide funding to enhance the model with more realistic wind and sea surface temperatures. The impact of this research would be through improvements in the representation of tropical convection in weather and climate models. The project would also help to train the next generation of scientists by involving multiple graduate students in the research.The overarching goal of the project is to understand how aggregation of convection in an environment more realistically representative of the tropics may help regulate tropical climate. The related hypothesis is that aggregation reduces tropical climate sensitivity by providing a powerful negative water vapor feedback that is highly temperature dependent. The researchers will introduce a diurnal cycle and wind shear to their simulations in order to decrease or eliminate the strong aggregation state lock that they found in their prior work. Sea surface temperatures would also be allowed to vary, which will let the researchers test the hypothesis that the existence of aggregation may drive the system's climate toward the critical sea surface temperature for aggregation. The next step will be to use the theoretical model to explore the climate sensitivity of the system by varying the solar constant and CO2. Finally, the researchers will test the hypothesis that the Madden-Julian Oscillation (MJO) results from self-aggregation of convection independent of larger atmospheric waves.

热带淋浴和雷暴在地球气候的调节中起着重要作用。 关于热带对流的一种理论是，随着海面温度的温暖，更多的云形成，大气变得更干燥。 虽然云层从变暖的表面减少了太阳辐射，但这种效果却被干燥的气氛所抵消，从而使更多的外向辐射通过。 这可能表明热带气候具有一定的自我调节水平。 为了研究这个想法，参与该项目的研究人员创建了一个理想化的计算机模型，以解决他们所谓的对流“自我聚集”。 这是云和雷暴倾向，将一起移动到集群中。 该奖项将提供资金，以更真实的风和海面温度来增强模型。 这项研究的影响将是通过改善天气和气候模型中热带对流的表示。 该项目还将通过参与研究来帮助培训下一代科学家。该项目的总体目标是了解如何更现实地代表热带的环境中对流的聚合可能有助于调节热带气候。 相关的假设是，聚集通过提供高度依赖性的强大负水蒸气反馈来降低热带气候灵敏度。 研究人员将向他们的模拟引入昼夜周期和风剪，以减少或消除他们在先前工作中发现的强聚集状态锁。 海面温度也将被允许变化，这将使研究人员检验以下假设：聚集的存在可能会使系统的气候朝着关键的海面温度朝着聚集。 下一步将是使用理论模型通过改变太阳常数和CO2来探索系统的气候灵敏度。 最后，研究人员将检验以下假设：Madden-Julian振荡（MJO）是由于对流的自我聚集而独立于大气波。