Inflow Boundary Layer of Atlantic Hurricanes

这项研究的目的是描述流入飓风的海洋边界层能量含量的演变及其与飓风强度变化的关系。这项工作将与美国国家海洋和大气局飓风研究司目前计划的侦察任务合作完成，以调查登陆飓风的能量。这项研究的主要新颖特点是，作为拉格朗日实验战略的一部分，计划部署NOAA/U夏威夷智能气球。拉格朗日实验利用了NOAA WP-3D飞机上新的高分辨率全球定位系统(GPS)滴风探测仪、湍流量传感器和多普勒雷达的可用性。由于流入中可能存在显著的横向变化，该计划包括获取关于流入层中气团的热力学历史和轨迹的关键现场数据。气象和GPS位置数据将由美国国家海洋和大气局空气资源实验室现场研究部开发的经过验证的气球携带仪器平台(Smart Balloon)收集。数据将通过卫星蜂窝电话传输到国家飓风中心(NHC)和WP-3D飞机。智能气球具有很大的动态升降范围(海平面到6公里)，由高强度球壳和内部加压气囊上的泵和释放阀提供。这种设计允许气球在边界层中保持在规定的高度运行极限内，尽管有降水负荷和辐射加热和冷却对气球升力的影响。仪器和应答器包裹将被装在气球的外壳内，以保护它们免受环境危害。在每一次野外实验开始时，两个智能气球将从距离经过的飓风250公里范围内的沿海位置部署。这一战略将允许NOAA WP-3D飞机在气球接近飓风眼壁时在气球附近进行一系列测量。释放气球的地点和时间将根据NCEP的风暴路径预测和夏威夷大学的气球轨迹预测来选择。受影响的美国海岸沿线的地点将作为释放点，以调查源自大陆的气流的演变和影响，而岛屿地点(例如波多黎各)可以作为释放点，调查在开阔海洋上残留的轨迹。这项研究将提高我们对飓风中心热力学和角动量场之间关系的理解。智能气球和飞机在试验期间收集的实时数据，特别是风数据，将提供给国家飓风中心和国家环境预测中心，以帮助准备登陆前的飓风强度预报、监测和警告。

The purpose of this research is to characterize the evolution of the energy content of the marine boundary-layer inflow to hurricanes and its relationship with hurricane intensity changes. This effort will be accomplished in cooperation with reconnaissance missions currently planned by the NOAA Hurricane Research Division to investigate the energetics of landfalling hurricanes. The key novel feature of this research is the planned deployment of NOAA/U of Hawaii Smart Balloons as part of a Lagrangian experimental strategy. The Lagrangian experiment leverages the availability of new high-resolution Global Positioning System (GPS) dropwindsondes, turbulent flux sensors, and the Doppler radar on the NOAA WP-3D aircraft.Since there may be significant cross-stream variability in the inflow, the plan includes acquisition of critical in situ data on the thermodynamic history and trajectories of air parcels in the inflow layer. Meteorological and GPS position data will be collected by a proven balloon-borne instrument platform (Smart Balloon), developed at NOAA's Air Resources Lab, Field Research Division. The data will be transmitted via satellite cellular telephone to the National Hurricane Center (NHC) and the WP-3D aircraft. The Smart Balloon has a large dynamic lift range (sea level to 6 km), provided by a high strength spherical shell and a pump and release valve on an internal pressurized air bladder. This design allows the balloons to remain within prescribed altitude operating limits in the boundary layer despite precipitation loading and effects of radiative heating and cooling on balloon lift. The instrument and transponder package will be contained within the outer shell of the balloon to protect them from environmental hazards.At the outset of each field experiment, two smart balloons will be deployed from a coastal location within 250 km of a passing hurricane. This strategy will allow the NOAA WP-3D aircraft to make a series of measurements in the vicinity of the balloons as they approach the hurricane eyewall. Balloon release sites and times will be chosen based on storm-track predictions from NCEP and forecasts of air-parcel trajectories made at the University of Hawaii. Sites along the affected US coast will serve as release points to investigate the evolution and impact of air streams of continental origin, while island sites (e.g., Puerto Rico) can serve as release points to investigate trajectories that remain over the open ocean. This research will improve our understanding of how the thermodynamics and angular momentum fields in the core of hurricanes are related. Real-time data, especially wind data, collected by the Smart Balloons and aircraft during the experiment will be made available to the National Hurricane Center and the National Center for Environmental Prediction to aid in preparation of hurricane intensity forecasts, watches, and warnings prior to landfall.