Gravity Wave Propagation, Momentum Fluxes and Instabilities Using the Jicamarca and JULIA Radars

研究人员将利用位于秘鲁利马附近Jicamarca的两台雷达进行为期三年的一系列实验，研究热带中层大气中的重力波动力学。目的是研究平流层和中间层从长周期到最短浮力波的饱和波谱产生过程。其中一个雷达是中间层-平流层-对流层雷达，另一个称为JULIA，是大型50 MHz Jicamarca非相干散射雷达的子系统。JULIA将连续运行整整一个月来测量平流层风。更大的Jicamarca系统将在本月内运行五天，以测量更大高度范围内的风。最近在Jicamarca进行的实验活动的初步证据表明存在孤立的波包。新的实验将使研究人员能够评估这些孤立波包对整个波谱的贡献。其他最近的实验表明，周期为1-3天的惯性重力波可能输送了驱动热带平流层准两年一次振荡的大部分动量。JULIA雷达的24小时覆盖范围将允许对低频波进行更全面的分析，并更准确地确定其固有波参数，从而为大规模的中层大气模型提供指导。这是伊利诺伊大学和西北研究协会的共同努力。伊利诺伊大学的研究人员将负责实验计划、数据采集和分析，而西北研究协会将负责对中期大气动力学的影响进行建模。

Abstract for Kudeki and Riggin proposals ATM 9709251 & ATM 9709030 The investigators will conduct a series of experiments using two radars located at Jicamarca near Lima, Peru, to study the gravity wave dynamics in the tropical middle atmosphere over a three-year time span. The objective is to study the processes that produce the saturated wave spectrum in the stratosphere and mesosphere from long periods to the shortest buoyancy waves. One of the radars is a mesosphere-stratosphere-troposphere radar and the other is called JULIA a subsystem of the large 50 MHz Jicamarca incoherent scatter radar. JULIA will be operated continuously for an entire month to measure stratospheric winds. The larger Jicamarca system will operate for a five-day campaign within the month to measure winds over a wider range of heights. Preliminary evidence from recent experimental campaigns at Jicamarca suggest the presence of isolated wave packets. The new experiments will allow the investigators to assess the contribution of these isolated wave packs to the overall wave spectrum. Other recent experiments suggest that inertia-gravity waves with periods of 1-3 days may transport much of the momentum that drives the quasi-biennial oscillation in the tropical stratosphere. The 24-hour coverage of the JULIA radar will allow more comprehensive analysis of the low-frequency waves and a more accurate determination of their intrinsic wave parameters to provide guidance for large-scale models of the middle atmosphere. This is a joint effort involving the University of Illinois and Northwest Research Associates. The University of Illinois investigators will be responsible for experiment planning and data acquisition and analysis, while Northwest Research Associates will be responsible for modeling the implications on middle atmospheric dynamics.