Collaborative Research: Measurement and Analysis of the Preconvective Boundary Layer and Convection Initiation during International H2O Project (IHOP)

合作研究：国际H2O项目（IHOP）期间对流前边界层和对流引发的测量和分析

• 批准号: 0130307
• 负责人: Paul Markowski
• 金额: $ 20.18万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-15 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0130307&HistoricalAwards=false
• 关键词: Collaborative; Research; Measurement; Analysis; Preconvective

This collaborative project between the University of Oklahoma and the Pennsylvania State University is part of the International H2O Project (IHOP). The IHOP is a large multi-agency, multi-investigator project that focuses on the measurement of water vapor and water vapor variability. The goal of this project is to improve understanding of convective initiation, increase short-term precipitation forecast skills and test the capabilities of various instruments to measure the four dimensional characteristics of water vapor. The field phase of the IHOP will be conducted during the Spring and Summer of 2002 and will provide a wide range of mesoscale meteorological observations for studies to gain a better understanding of the scales of, and processes influencing, water vapor variability.The goal of this hypothesis-driven research is to improve understanding of the processes leading to the initiation of deep, moist cumulus convection. Though several studies have examined certain aspects of boundary layer structure little is known about what causes convective initiation. IHOP will provide the comprehensive data sets needed to begin evaluating and revising hypotheses concerning convection initiation processes and the role of boundary layer water vapor. The Principal Investigators will acquire and analyze three dimensional radar-derived boundary layer airflow and in-situ measurements of winds and thermodynamic parameters from mobile facilities. The combination of boundary layer airflow with in-situ measurements of absolute humidity and virtual temperature provides the only means of documenting the dynamical and transport processes acting in the boundary layer to regulate precipitable water and force the development of secondary circulations. Thus these observations are essential for evaluating hypotheses concerning the impact of water vapor supply and airflow evolution on boundary formation and convection initiation.Detailed observations will be analyzed in several different ways. Subjective analyses and visualizations will be produced incorporating all available data on relevant scales for convection initiation. Observation density will be enhanced utilizing an advanced time-to-space conversion scheme by distributing nearly conservative variables along Lagrangian trajectories based on multi-Doppler wind syntheses. Finally, these enhanced observations will be assimilated into mesoscale models to determine the dynamical forcing processes controlling the development of localized boundary layer circulations that either promote or prevent convection initiation.This effort will result in the collection and analysis of an unprecedented data set at scales previously not observed. Through this work, a completely new understanding will emerge regarding the processes occurring near low-level boundaries and how these processes regulate the formation of thunderstorms. The knowledge will be useful for developing new advances, both numerical and subjective, in quantitative precipitation forecasting by improving the ability to forecast if, when, and where convection will develop.

俄克拉荷马大学和宾夕法尼亚州立大学之间的合作项目是国际 H2O 项目 (IHOP) 的一部分。 IHOP 是一个大型的多机构、多研究者项目，专注于水蒸气和水蒸气变异性的测量。 该项目的目标是提高对对流引发的认识，提高短期降水预报技能，并测试各种仪器测量水蒸气四维特征的能力。 IHOP 的实地阶段将于 2002 年春季和夏季进行，将为研究提供广泛的中尺度气象观测，以便更好地了解水汽变化的规模和影响过程。假设驱动的研究旨在提高对导致深层湿积云对流启动的过程的理解。 尽管一些研究已经检验了边界层结构的某些方面，但对于引发对流的原因却知之甚少。 IHOP 将提供开始评估和修改有关对流引发过程和边界层水蒸气作用的假设所需的全面数据集。 主要研究人员将获取并分析三维雷达衍生的边界层气流以及来自移动设施的风和热力学参数的现场测量。 边界层气流与绝对湿度和虚拟温度的现场测量相结合，提供了记录边界层中作用的动力和传输过程的唯一方法，以调节可降水并迫使二次循环的发展。 因此，这些观测对于评估有关水蒸气供应和气流演化对边界形成和对流引发的影响的假设至关重要。详细的观测将以几种不同的方式进行分析。 将结合对流引发相关尺度的所有可用数据来生成主观分析和可视化。 利用先进的时空转换方案，通过基于多普勒风合成的拉格朗日轨迹分布近乎保守的变量，可以提高观测密度。 最后，这些增强的观测结果将被同化到中尺度模型中，以确定控制局部边界层环流发展的动力强迫过程，从而促进或阻止对流的引发。这项工作将收集和分析以前规模的前所未有的数据集。没有观察到。 通过这项工作，将对低层边界附近发生的过程以及这些过程如何调节雷暴的形成产生全新的理解。 这些知识将有助于提高定量降水预报是否、何时以及何处发生对流的能力，从而有助于在数值和主观方面取得新进展。