Atmospheric Wind Evaluation using Spectroscopic Observations of Millimetre-wave Emission (AWESOME)

我们建议使用地面毫米波辐射测量法结合最新的接收器和光谱仪技术，进行世界上第一次大气风测量。这种遥感技术将提供平流层和中间层水平风的连续、精确观测，其细节前所未有，覆盖高度20-70公里，目前测量非常有限。该设备坚固耐用，易于自动化，可部署在恶劣的偏远环境中，包括极地地区，在那里地面或卫星对风的观测非常有限。这将开辟大气科学的新领域，研究大气动力学、环流、波浪和潮汐——与了解极地和全球气候高度相关。最终，提出的观测将导致气候模式和天气预报的进步。风辐射测量技术类似于交通“雷达枪”。然而，风速不是检测车辆反射的发射机信号，而是通过空气中运动分子发出的旋转发射信号的多普勒频移来确定的。通过从相反的方位（例如指向东西或南北）测量大气，可以确定纬向风和经向风的分量。虽然这种无源技术可以在恶劣的天气条件下工作，并且不需要有源发射源，但它确实需要精确的频率测量，现在可以使用稳定的高分辨率光谱仪来实现。利用微波和亚毫米辐射测量的风廓线最近得到了证实。我们建议将该技术扩展到毫米波，那里的多普勒频移比微波更大，更容易测量，大气衰减比亚毫米波区域低。在我们的论文研究中（将技术准备水平提高到~3-4级），我们将使用基于计算机的大气模拟和检索计算来确定部署在北极和南极高纬度地区的地面敏感230-250 GHz辐射计的水平风廓线能力。我们将研究这种观测技术在大气潮汐和波浪活动研究中的应用，在冬季平流层突然变暖事件中，大气潮汐和波浪活动可能导致中高纬度地区强烈的东风突然减弱甚至逆转。这些大气过程可导致低层和高层大气之间的强烈耦合，有时与整个欧洲可能出现的破坏性寒冷天气有关。拟议的工作与NERC的五个研究主题相关，并将建立英国在毫米波传感和大气检索方面的专业知识。

We propose the world's first measurements of atmospheric winds using ground-based millimetre-wave radiometry incorporating recent advances in receiver and spectrometer technology. This remote sensing technique will provide continuous, precise observations of horizontal winds in the stratosphere and mesosphere with unprecedented detail, covering the altitudes 20-70 km where measurements are currently very limited. The equipment will be robust and readily automated for deployment in harsh, remote environments including the Polar Regions where ground-based or satellite observations of winds are extremely limited. This will open up new areas of atmospheric science investigating atmospheric dynamics, circulation, waves, and tides - highly relevant to understanding polar and global climate. Ultimately the proposed observations will lead to advances in climate models and weather forecasting. The technique of wind radiometry is analogous to a traffic 'radar gun'. However instead of detecting a transmitter signal reflected by vehicles, the wind speed is determined from the Doppler shift of rotational emission signals originating from moving molecules in the air. By taking atmospheric measurements from opposite azimuthal directions (e.g. pointing east and west or north and south) the zonal and meridional wind components are determined. While this passive technique works in adverse weather conditions and doesn't need an active transmitter source, it does require accurate frequency measurements that can now be achieved using stable, high resolution spectrometers. Wind profiling using microwave and sub-millimetre radiometry has recently been demonstrated. We propose extending the technique to the millimetre-wave where the Doppler shifts are larger and more readily measured than in the microwave and atmospheric attenuation is lower than in the sub-millimetre region. In our paper study (raising the technology readiness level to ~3-4) we will use computer-based atmospheric simulations and retrieval calculations to determine the horizontal wind profiling capability of a sensitive ground-based 230-250 GHz radiometer deployed at high-latitude locations in the Arctic and Antarctic. We will investigate applications of this observing technique in studies of atmospheric tides and wave activity that can cause abrupt weakening or even reversal of the strong eastward winds at mid- and high latitudes during winter-time sudden stratospheric warming events. These atmospheric processes can lead to strong coupling between the lower and upper atmosphere and are sometimes linked to the onset of potentially disruptive cold weather across Europe. The proposed work is relevant to five NERC research topics and will build UK expertise in millimetre-wave sensing and atmospheric retrieval.