A Study of the Efficacy of Conceptual Models for Air-Sea Gas Transfer

海气输送概念模型的有效性研究

• 批准号: 0924992
• 负责人: William Asher
• 金额: $ 65.55万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0924992&HistoricalAwards=false
• 关键词: Study; Efficacy; Conceptual; Models; Air

Air-sea exchange is a critical process in climate, as the oceans are a both a source and a sink for CO2, CH4, and trace species important in atmospheric chemistry and radiative transfer. This project aims to enhance our understanding of small-scale physics relevant for air-sea gas exchange, and to develop an effective method for using infrared imagery to estimate air-sea gas fluxes.The objective of the research is to:1. Determine if surface divergence models for water-side rate-controlled air-water transfer processes provide an accurate physical description of gas exchange.2. Determine if infrared images of the water surface can provide distributions of the temporal and depth scales required to use surface divergence models for predicting air-water gas fluxes.This research will use laboratory gas transfer data collected in a synthetic jet array tank (SJAT) to test a surface divergence model for air-water transfer of gas and heat. In particular, it will investigate the ability of the model to predict the measured air-water transfer velocities and their dependence on molecular diffusivity under conditions where the exchange process is forced by either mechanically generated turbulence or wind stress. Near-surface concentration fluctuations of carbon dioxide (CO2) will be measured using a laser-induced fluorescence technique and bulk gas fluxes will be measured for helium, sulfur hexafluoride, methane, and CO2. Infrared imagery will be used to characterize near-surface temperature fluctuations. Broader ImpactsThe project will promote teaching, training, and learning through such things as mentoring a post-doctoral research associate, participation of a summer undergraduate research intern, hands-on demonstrations on air-water gas transfer at venues such as the Earth Observations from Space Weekend at the Pacific Science Center, participation of the researchers in various outreach activities ranging from seminars on global climate change to laboratory tours and recruitment of summer research interns from underrepresented groups.

海-气交换是气候中的一个关键过程，因为海洋既是二氧化碳、甲烷的源，也是二氧化碳、甲烷和在大气化学和辐射传输中重要的痕量物种的汇。本项目旨在加深我们对与海-气交换相关的小尺度物理的理解，并发展一种利用红外图像估算海-气交换通量的有效方法。研究的目的是：1.确定水侧速率控制的气-水传输过程的地表散度模型是否能准确地描述气体交换。确定水面的红外图像是否可以提供使用表面散度模型来预测空气-水气体通量所需的时间和深度尺度的分布。这项研究将使用在合成射流阵列储罐(SJAT)中收集的实验室气体传输数据来测试用于气-水气体和热量传输的表面散度模型。特别是，它将调查该模型预测测量的空气-水转移速度的能力，以及在交换过程由机械产生的湍流或风应力强迫的条件下，它们对分子扩散率的依赖。将使用激光诱导荧光技术测量二氧化碳(CO2)的近地表浓度波动，并将测量氦、六氟化硫、甲烷和二氧化碳的整体气体通量。红外图像将被用来描述近地表的温度波动。更广泛的影响该项目将通过以下方式促进教学、培训和学习：指导博士后研究助理，参加夏季本科生研究实习生，在太平洋科学中心的地球观测周末等场所实际演示气水气体转移，研究人员参与各种外联活动，从全球气候变化研讨会到实验室参观，以及从代表性不足的群体招聘夏季研究实习生。