Collaborative Research: Doppler on Wheels International H2O Project Participation and Studies of Convective Initiation

国际H20项目(IHOP)是一个多研究者、多机构的项目，其主要目标是改善水汽四维分布的特征，并将其应用于改善对流的理解和预测。方案重点放在四个重要的研究领域：定量降水预报；对流启动、大气边界层过程；以及仪器测试。IHOP成功的关键是跨几个运动尺度的风和热力学值的测量。这将通过独特和多样化的仪器设备来实现。为促进实现国际水文计划的目标，首席调查员提交了合作建议书。作为IHOP所需仪器套件的一部分，首席调查人员将部署俄克拉荷马大学车轮上的多普勒雷达(DOW)。这些雷达为IHOP的研究人员提供了一种高分辨率的仪器，用于获取详细的风向测量数据。这些测量适用于IHOP的所有四个研究组成部分。DOW将与固定地点和移动观测平台协调，以前所未有的数据密度和分辨率对对流前环境进行采样，包括边界和辐合线内和沿线的风和热力性质。为了对IHOP的研究做出贡献，首席研究人员将分析这些数据，以阐明水汽场中梯度的大小和风场在聚焦这些不均匀方面的作用。例如，首席调查人员将确定沿辐合区边界或交叉点的局部辐合中尺度环流是否会产生高水汽含量，这可能与水平对流卷(HCR)有关。他们将进一步评估与HCRS有关的水汽梯度的方向。除了边界研究外，首席调查员还将对没有明显会聚带的日子收集的数据进行分析，以确定在没有实质性聚焦机制的情况下水汽场的变化程度。在了解了对流前环境中水汽变化的性质和程度后，将根据目前的假设，进一步分析这些不均匀与对流启动过程的关系。例如，如果发现存在水汽含量较高的区域，首席调查员将研究这些位置是否确实有利于深层对流。他们将详细检查与观测到的极小尺度环流和辐合区有关的抬升深度，以确定水蒸气在边界层中的输送。目标是更好地了解控制对流前环境中水汽可变性的机制以及这种可变性在对流启动过程中表现出来的动力过程。

The International H20 Project (IHOP) is a multi-investigator, multi-agency program whose chief aim is improved characterization of the four-dimensional distribution of water vapor and its application to improving the understanding and prediction of convection. Program emphasis is on four important research areas: quantitative precipitation forecasting; convective initiation, atmospheric boundary layer processes; and instrumentation testing. Critical to the success of the IHOP is the measurement of wind and thermodynamic values spanning several scales of motion. This will be accomplished with unique and varied instrumentation. To contribute to achieving the goals of IHOP, the Principal Investigators have submitted collaborative proposals. As part of the required IHOP instrumentation suite, the Principal Investigators will deploy the University of Oklahoma Doppler on Wheels (DOW) radars. These radars provide the IHOP researchers with a high resolution instrument for obtaining detailed wind measurements. These measurements have applications to all four IHOP research components. The DOWs will coordinate with both fixed-site and mobile observing platforms to sample with unprecedented data density and resolution the pre-convective environment, including wind and thermodynamic properties within and along boundaries and convergence lines.For their research contribution to the IHOP, the Principal Investigators will analyze these data to elucidate the magnitude of gradients in the water vapor field and the role of the wind field in focusing these inhomogeneities. For example, the Principal Investigators will determine if locally convergent mesoscale circulations along boundaries or intersections between convergence zones, possibly associated with horizontal convective rolls (HCRs), create pockets of high water vapor content. They will further assess the orientation of water vapor gradients with respect to the HCRs. In addition to boundary studies, the Principal Investigators will perform analyses of data collected on days without obvious convergence zones to determine the degree of variability in the water vapor field in the absence of substantial focusing mechanisms. After understanding the nature and degree of water vapor variability in the pre-convective environment further analysis will focus on the relationship of these inhomogeneities to the convective initiation process based on current hypotheses. For example, if pockets of high water vapor content are found to exist, the Principal Investigators will then examine whether deep convection indeed is favored at these locations. They will examine in detail the depth of lifting associated with observed very small scale circulations and convergence zones to determine the transport of water vapor in the boundary layer. The goal is a better understanding of the mechanisms governing water vapor variability in the preconvective environment and the dynamical processes by which this variability is manifested in the convective initiation process.