Water Vapor, Clouds, and Aerosol in the Tropical Tropopause Layer with in situ and Profiling Measurements from Long Duration Strateole-2 Balloons

热带对流层顶层中的水蒸气、云和气溶胶，通过长期 Strateole-2 气球进行原位和剖面测量

• 批准号: 1643022
• 负责人: Terry Deshler
• 金额: $ 125.81万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643022&HistoricalAwards=false
• 关键词: Water; Vapor; Clouds; Aerosol; Tropical

The tropical tropopause layer (TTL) is transition zone between the troposphere (the domain of clouds, precipitation, and weather systems) and the stratosphere (the cold and dry region above it which contains the ozone layer). The TTL extends from about 14 to 18.5km over the tropics and is above the tops of all but the tallest convective clouds. It often contains thin cirrus clouds which, though difficult to see, play an outsized role in trapping outgoing radiation and thus warming the troposphere. It is sometimes called the "gateway to the stratosphere" because most of the water vapor in the stratosphere, and many other stratospheric constituents, enter the stratosphere by moving upward through the TTL. The stratosphere is extremely dry compared to the troposphere, but stratospheric water vapor is of interest because it has an important greenhouse effect and can lead to the formation of polar stratospheric clouds which play a role in ozone hole formation.This project seeks to improve understanding of TTL processes by building and launching several instruments on balloons intended to fly at the top of the TTL. The balloons are part of the Strateole-2 field campaign organized by the Centre National d'Etudes Spatiales (CNES), the French Space Agency, and the Laboratoire de Meteorologie Dynamic (LMD) of the University of Paris-Saclay. Strateole-2 is a five-year campaign, with a small validation deployment in 2018 and full science deployments in 2020-2021 and 2022-2023. Balloons are launched from the Seychelles (about 5S in the Indian Ocean), with the expectation that each balloon will circle the earth for up to 90 days and observe the TTL between 20S and 15N. This award supports US participation in the validation campaign and the first full science deployment, along with post-campaign analysis. It is one of three awards made to US PIs for participation in Strateole-2, the full set being AGS-1643022, AGS-1642277/1642246, and AGS-1642650/1653644.One instrument to be built and deployed is an optical particle detector referred to as the LASP Particle Counter (LPC, named after the Laboratory for Atmospheric and Space Physics at the University of Colorado). The LPC uses scattered laser light to detect aerosol particles with sizes ranging from 0.3 to 10 microns and is used to estimate the flux of aerosols entering the stratosphere through the top of the TTL. In addition to the LPC the PIs are developing an instrument package called RACHuTS, for Reel-down Aerosol Cloud Humidity and Temperature Sensor. The RACHuTS package weighs less than 2kg and is suspended from a nylon cable which is reeled down to 2km below the balloon gondola and then reeled back up again, each time generating a vertical profile of TTL conditions over 15 minutes. RACHuTS is lowered and raised 5 times each night while the balloon is aloft (the optical components do not function in daylight). The instruments integrated into RACHuTS are developed elsewhere. These include the Compact Optical Backscatter Aerosol Detector (COBALD, developed at ETH Zurich), the Fluorescence Advanced Stratospheric Hygrometer for Balloon (FLASH-B, developed at the Central Aerological Observatory in Moscow), and the Thermodynamic SENsor (TSEN, developed at LMD). A commercial radiosonde package is also used to record atmospheric pressure and GPS position.One issue to be addressed in the project is the extent to which supersaturation is an important consideration in determining how much water vapor passes through the TTL and enters the stratosphere. The amount of water vapor entering the stratosphere is limited by the temperature minimum at the tropopause, under the assumption that the amount of water vapor above that level cannot exceed the amount corresponding to 100% relative humidity at that level. But it is possibly for relative humidity to exceed 100% in cases where ice particle concentrations are low enough and ascent is fast enough to allow moisture to reach the stratosphere before sublimation can occur. The RACHuTS instruments are well suited to the study of supersaturation effects as temperature, humidity, and ice particle concentrations are observed together over a substantial portion of the depth of the TTL. A further issue, to be addressed using the LPC, is the transport of primary aerosols into the stratosphere. The PIs seek to constrain the size distribution of these areosols and address questions related to the stability of the distribution, its geographical variability, its relationship to convective overshooting, and previous observations of large particles with low number concentrations.The work has scientific broader impacts due to the value of the observations for addressing a variety of questions regarding TTL processes. RACHuTS and LPC observations will be made available to the research community from servers at LASP so that it can be freely examined by the research community. In addition, the project constitutes a demonstration of a novel technology for meteorological observations which could have a wide array of scientific applications. Beyond these considerations, the project supports a postdoctoral research associate, thereby developing the future scientific workforce in this research area.

热带对流层层层（TTL）是对流层（云，降水和天气系统的域）和平流层（其中包含臭氧层的冷和干燥区域）之间的过渡区。 TTL在热带地区从大约14公里处延伸至18.5公里，并且在最高的对流云之外的所有顶部。 它通常包含薄薄的卷云云，尽管很难看到，但在捕获向外的辐射并因此变暖对流层方面起着出色的作用。 它有时被称为“通往平流层的门户”，因为平流层中的大多数水蒸气以及许多其他平流层成分，通过通过TTL向上移动进入平流层。 与对流层相比，平流层非常干燥，但是平流层水蒸气引起了人们的关注，因为它具有重要的温室效应，并且可以导致极地平流层云的形成，这些云在臭氧孔形成中发挥作用。该项目旨在通过在TTTL上构建和启动对球体的构建和启动多种乐器来提高对TTL过程的理解。 气球是由中心国家D'Etudes Spatiales（CNES），法国航天局和巴黎 - 萨克莱大学的Laboratoire De Meteorologie Dynamic（LMD）组织的Strateo-2现场运动的一部分。 Strateo-2是一项为期五年的运动，在2018年进行了少量验证部署，并在2020 - 2021年和2022 - 2023年进行了全面的科学部署。 气球是从塞舌尔（Sehehelles）发射的（印度洋约5秒），期望每个气球会绕地球旋转长达90天，并观察到20年代至15N之间的TTL。该奖项支持我们参与验证活动和第一个完整的科学部署以及挑战后分析。 它是向美国PIS颁发的三个奖项之一，全套为AGS-1643022，AGS-1642277/1642246和AGS-1642650/1653644。要构建和部署的一种仪器是一种光学粒子探测器，是一种光学粒子探测器，称为LPC的空间（LPC），该工具属于LPC，命名为LPC的氛围，该工具属于LPC的氛围，并将其命名为“ LPC”和“ LPC”的氛围。 LPC使用散射的激光检测尺寸为0.3至10微米的气溶胶颗粒，用于估计通过TTL顶部进入平流层进入平流层的气溶胶的通量。 除LPC外，PI还开发了一个称为Rachuts的仪器包，用于卷盘降低气溶胶云湿度和温度传感器。 Rachuts套件的重量小于2kg，并从尼龙电缆悬挂下来，该电缆在气球缆车下方下方降低至2km，然后再次卷回去，每次在15分钟内产生TTL条件的垂直轮廓。在气球高高的同时，每晚降低了Rachuts，并每晚升高5次（光学组件在白天不起作用）。集成到rachuts中的仪器是在其他地方开发的。 其中包括紧凑的光散射气溶胶检测器（Cobald，在Eth Zurich开发），用于球囊的荧光高级平流层湿度计（在莫斯科的中央气管天文台开发）和热力学传感器（TSEN，在LMD上开发）。商业辐射软件包还用于记录大气压力和GPS位置。项目中要解决的一个问题是，在确定多少水蒸气通过TTL并进入平流层的重要性方面是重要的考虑因素。 在对流层顶处温度最低的水蒸气量受到限制，因为假设水蒸气的量超过该水平的水平不能超过该水平上对应于100％相对湿度的量。 但是，在冰颗粒浓度足够低并且上升足够快的情况下，相对湿度可能会超过100％，以使水分在升华之前到达平流层。 Rachuts仪器非常适合研究过饱和效应，因为温度，湿度和冰颗粒浓度在TTL深度的很大一部分上共同观察到。 要使用LPC解决的另一个问题是将原代气溶胶运输到平流层中。 PI试图限制这些肌醇的尺寸分布，并解决与分布的稳定性，其地理变异性，其与对流过度交锋的关系以及对较低数量浓度的大粒子的先前观察结果的问题。该工作具有更广泛的影响。由于解决了有关TTL流程的各种问题的价值，因此具有更广泛的影响。 Rachuts和LPC的观察将从LASP的服务器提供给研究社区，以便可以由研究界自由检查。 此外，该项目构成了一种新型技术的演示，用于气象学观察，该技术可能具有广泛的科学应用。 除了这些考虑之外，该项目还支持博士后研究助理，从而在该研究领域发展了未来的科学劳动力。

项目成果

First Super‐Pressure Balloon‐Borne Fine‐Vertical‐Scale Profiles in the Upper TTL: Impacts of Atmospheric Waves on Cirrus Clouds and the QBO

第一个超压气球 - TTL 上部的精细 - 垂直 - 尺度剖面：大气波对卷云和 QBO 的影响

• DOI: 10.1029/2021gl097596
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Bramberger, Martina;Alexander, M. Joan;Davis, Sean;Podglajen, Aurelien;Hertzog, Albert;Kalnajs, Lars;Deshler, Terry;Goetz, J. Douglas;Khaykin, Sergey
• 通讯作者: Khaykin, Sergey

A reel-down instrument system for profile measurements of water vapor, temperature, clouds, and aerosol beneath constant-altitude scientific balloons

用于恒定高度科学气球下方水蒸气、温度、云和气溶胶轮廓测量的卷轴仪器系统

• DOI: 10.5194/amt-14-2635-2021
• 发表时间: 2021
• 期刊: Atmospheric Measurement Techniques
• 影响因子: 3.8
• 作者: Kalnajs, Lars E.;Davis, Sean M.;Goetz, J. Douglas;Deshler, Terry;Khaykin, Sergey;St. Clair, Alex;Hertzog, Albert;Bordereau, Jerome;Lykov, Alexey
• 通讯作者: Lykov, Alexey