A Study of the Dynamics of the Marine Stratocumulus Boundary Layer Using Fast Dimethyl Sulfide (DMS) Measurements

利用快速二甲硫醚 (DMS) 测量研究海洋层积云边界层动力学

• 批准号: 0004444
• 负责人: Alan Bandy
• 金额: $ 15.87万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0004444&HistoricalAwards=false
• 关键词: Study; Dynamics; Marine; Stratocumulus; Boundary

This grant supports the deployment of a fast-response, airborne instrument for measuring the concentration of dimethyl sulfide (DMS) during the DYCOMS-II project in July 2001 (Dynamics and Chemistry of Marine Stratocumulus). DMS is an atmospheric trace gas which is an effective indicator of mixing between the marine boundary layer and the free atmosphere. Its main source is the ocean surface and its lifetime in the atmosphere is about one day. It therefore has relatively high concentration in the boundary layer and low concentration in the free atmosphere. Fluctuations in the concentration at the top of the boundary are an indication of the strength of mixing and the rate of mass transfer between the boundary layer and the air above. The instrument is a fast-response ionization mass spectrometer capable of yielding data with a time resolution of 50 ms. In combination with other aircraft instruments that measure temperature, vertical air velocity, humidity, cloud droplet concentration and sizes, and aerosol sizes and composition, it will provide information on entrainment processes at cloud top. The data will be used in the testing and evaluation of large eddy simulations of mixing in marine stratocumulus clouds.

这笔赠款支持在2001年7月的DYCOMS-II项目(海洋层积云的动力学和化学)期间部署一台快速反应的机载仪器，用于测量二甲基硫的浓度。DMS是一种大气痕量气体，是海洋边界层和自由大气之间混合的有效指示器。它的主要来源是海洋表面，它在大气中的寿命约为一天。因此，它在边界层中的浓度相对较高，而在自由大气中的浓度较低。边界层顶部浓度的波动是混合强度和边界层与上方空气之间传质速率的指示。该仪器是一种快速响应的电离质谱仪，能够产生时间分辨率为50ms的数据。与测量温度、垂直风速、湿度、云滴浓度和大小以及气溶胶大小和成分的其他飞机仪器相结合，它将提供有关云顶卷吸过程的信息。这些数据将用于测试和评估海洋层积云中混合的大涡模拟。