Collaborative Research: Studies of Waves and Circulation Features in the Antarctic Stratosphere Using Super-Pressure Balloon Data

该项目基于超压气球(SPBS)的数据对南极平流层极涡的环流进行了研究。SPBS有一个半刚性包层，在来自内部气体的压力下，无论加热和冷却，它都保持恒定的体积和恒定的有效密度，因此它们沿着密度恒定的几乎水平的表面移动。该项目的数据来自两个实地活动，VORCORE(2005年27个SPBS)和CONCORDIASI(2010年18个SPBS)，这两个活动都从南极洲发射了气球，气球上升到70至50毫巴的水平，并在极涡中循环了几个月。SPBS携带的仪器包括微型滴漏探测仪、用于掩星探测的GPS接收器、臭氧传感器和云冰颗粒计数器。该奖项研究的是惯性重力波和极涡内部的大尺度传输，具体目标有四：1)在空间和光谱领域对南极上空的惯性波场和重力波场进行准确的统计描述；2)根据重力波动量通量的计算得出重力波参数化的约束条件；3)重力波对极地平流层云(PSCs)的形成的影响；4)与极涡有关的空气交换和传输中的基本动力学过程，重点是Rossby波破裂的作用。这项工作使用了观测分析和建模相结合的方法，并使用了动力系统理论驱动的新方法来解决极地涡旋之间和极地涡旋内部的空气交换和传输。首先，这里研究的过程都与臭氧层空洞的形成有关，因为臭氧消耗取决于平流层空气穿过极涡和极涡内部的输送和混合，而重力波运动可能在PSC的形成中发挥作用。其次，重力波动量通量被认为在决定大气环流强度方面起着重要作用，在天气和气候模式中对重力波的影响进行了参数估计。因此，重力波特性的观测分析可能有助于天气和气候的模拟和预测。此外，这项工作将支持和培养一名研究生，从而为这一领域的下一代科学家提供支持。

This project conducts research on the circulation of the Antarctic stratospheric polar vortex based on data from super pressure balloons (SPBs). SPBs have a semi-rigid envelope which, under pressure from the gas inside, maintains constant volume and hence constant effective density regardless of heating and cooling, so that they move with the wind along a nearly horizontal surface of constant density. Data for this project comes from two field campaigns,VORCORE (27 SPBs in 2005) and CONCORDIASI (18 SPBs in 2010), both of which launched balloons from Antarctica which rose to levels between 70 and 50mb and circulated within the polar vortex for several months. Instruments carried by the SPBs included miniaturized dropsondes, GPS receivers for occultation soundings, ozone sensors, and cloud ice particle counters. Research conducted under this award studies inertia-gravity waves and large-scale transport across and within the polar vortex, with four specific objectives: 1) The accurate statistical descriptions of the inertial and gravity wave fields over the Antarctic in the spatial and spectral domains, 2) The formulation of constraints for gravity wave parameterizations based on calculation of gravity wave momentum flux, 3) The influence of gravity waves on the formation of polar stratospheric clouds (PSCs, which play an important role in ozone depletion), and 4) The fundamental dynamical process at work in air exchanges and transports in relation to the polar vortex, with an emphasis on the role of Rossby wave breaking. The work uses a combination of observational analysis and modeling, and uses novel methods motivated by dynamical systems theory to address air exchange and transport across and within the polar vortex.The problems addressed in the proposal are of societal as well as scientific interest for two reasons. First, the processes examined here are all relevant to the formation of the ozone hole, as ozone depletion depends on transport and mixing of stratospheric air across and within the polar vortex, and gravity wave motions may play a role in the formation of PSCs. Second, gravity wave momentum fluxes are thought to play an important role in determining the strength of atmospheric circulation, and the effects of gravity waves are paremeterized in weather and climate models. Thus, observational analysis of gravity wave properties may be beneficial for weather and climate modeling and prediction. In addition, the work will support and train a graduate student, thereby providing for the next generation of scientists in this field.