Physics and Dynamics of the Tropical Cyclone Cirrus Canopy

拟议的工作旨在提高对热带气旋动力学和热力学的认识，特别强调大西洋盆地的飓风和热带风暴，特别是对流层/卷云冠层上部。 该团队建议阐明控制冠层内对流（以及TC内可能的降雨）的昼夜脉冲的因素，这是热带气旋研究界中一个有趣且相对较新的问题，并且可能对TC路径和强度预测产生有趣的影响。 该小组建议使用一系列数值模型来调查对流层上层稳定性的来源和后果;特别是使用NASA全球鹰和NOAA G-IV的现有和未充分利用的观测结果。 这项工作将涉及培训若干研究生;目标是从代表性不足的群体中招收学生。 这项研究的社会效益是通过潜在的改进飓风跟踪和强度预报。 这项研究试图利用大量的空中观测和数值模式来研究与热带气旋相关的高云物理。这些观测包括来自NOAA G-IV飞机、G-IV和NASA全球鹰的投下式探空仪的未充分利用的飞行层湍流数据。 本研究将描述热带气旋的湍流分布、低理查森数及多重对流层顶结构。重点将放在高云内外的差异以及一天中的时间。 该研究还将评估每日变化，重点是最近发现的向外传播的高云量脉冲。

The proposed work seeks to improve understanding of the dynamics and thermodynamics of tropical cyclones (TCs), with a specific emphasis on hurricanes and tropical storms in the Atlantic Ocean basin, specifically within the upper troposphere/cirrus canopy. The team proposes to elucidate the factors controlling diurnal pulses in convection within the canopy (and possibly rainfall within the TC), which is an interesting and relatively new question within the tropical cyclone research community, and one that may have interesting implications for TC track and intensity forecasts. The team proposes to use a hierarchy of numerical models to investigate the sources and consequences of upper tropospheric stability; especially the use of existing and under-utilized observations from the NASA Global Hawk and NOAA G-IV. This work will involve the training of several graduate students; with a goal to recruit students from underrepresented groups. The societal benefit of this study is through the potential improvements to hurricane track and intensity forecasts. This study seeks to utilize a large set of airborne observations and numerical models to study the physics of high clouds associated with tropical cyclones. The observations comprise under-utilized flight-level turbulence data from the NOAA G-IV aircraft, dropsondes from the G-IV and the NASA Global Hawks. This study will describe the distribution of turbulence, low Richardson number, and multiple tropopause structures in tropical cyclones. The emphasis will be on differences within and beyond the high clouds and with respect to time of day. The study will also evaluate daily variations, with focus on the recently discovered, outward-propagating pulses of high cloudiness.