IRFP: The Impact of the Double Tropopause on the Composition of the Upper Troposphere and Lower Stratosphere

国际研究奖学金项目使美国科学家和工程师能够在国外进行9至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Tanya R. Peevey博士与Paul Konopka博士在德国j<s:1> lich的Forschungszentrum j<s:1> lich进行为期12个月的研究。在对流层上部平流层下部（UTLS）区域的地球大气垂直结构中，可以看到多个稳定层，通常称为双对流层顶。UTLS是地球大气的一个关键区域，因为它包含各种重要的辐射物质，例如水蒸气、臭氧和气溶胶，随着时间的推移，由于其他温室气体（ghg）增加，从地球表面逸出的长波辐射减少，这些物质受到干扰。双对流层顶最常在中纬度地区形成，并与南半球和南半球之间的气团交换有关。气团交换事件可以通过调整局部温度剖面和区域的静态稳定性来改变局部的辐射平衡，这反过来又可以改变大气结构并导致向极地移动，例如中纬度风暴路径。评估与双对流层顶相关的运输对UTLS地区辐射重要物种的分布和再分布的影响，对于了解和预测地球的辐射收支，从而了解气候和气候变化具有重要意义。该研究项目将利用NASA Aura卫星上的高分辨率动态边缘测深仪（HIRDLS）的卫星观测和德国Forschungszentrum j<s:1> lich开发的平流层化学拉格朗日模型（CLaMS）的模型模拟的独特组合来研究地球大气的UTLS区域。该项目的第一个目标是确定双对流层顶内的空气起源于何处，因为它可能改变UTLS的组成，从而改变地球的辐射收支。第二个目标是了解双对流层顶和对流层顶逆温层（TIL）之间的关系，这是其他科学家最近使用干大气模型提出的一种关系。该研究发现，没有TIL的存在，双对流层顶就不可能形成。这种联系是出乎意料的，因为这两种大气特征具有相反的空间偏好和季节周期，因此将使用高垂直分辨率的观测和专门用于UTLS的模式来探索这种关系。除了加深对UTLS区域和地球气候的了解外，该项目的另一个好处是PI与德国主办机构之间的专业知识交流。Peevey博士将从这次交流中受益匪浅，他将获得拉格朗日模型的知识和运行模型模拟的技能。

The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twelve-month research fellowship by Dr. Tanya R. Peevey to work with Dr. Paul Konopka at Forschungszentrum Jülich in Jülich, Germany.Multiple stable layers, usually called a double tropopause, are seen in the vertical structure of the Earth's atmosphere within the upper troposphere lower stratosphere (UTLS) region. The UTLS is a key region of the Earth's atmosphere since it contains various radiatively important species, e.g. water vapor, ozone and aerosols, which have been perturbed over time due to less long-wave radiation escaping from the Earth surface as other green house gases (GHGs) increase. The double tropopause forms most frequently in the mid-latitudes and has been associated with an exchange of air masses between the UT and LS. Air mass exchange events can change the local radiative balance by adjusting the local temperature profile and the static stability of the region, which in turn can change the structure of the atmosphere and result in a poleward shift the midlatitude storm tracks for example. Evaluating the impact of double tropopause related transport on the distribution and redistribution of radiatively important species in the UTLS region is important for understanding and predicting the Earth's radiation budget and, consequently, climate and climate change.This research project will study the UTLS region of the Earth's atmosphere using a unique combination of satellite observations from the High Resolution Dynamic Limb Sounder (HIRDLS), an instrument on the NASA Aura satellite, and model simulations from the Chemistry Lagrangian Model of the Stratosphere (CLaMS), developed at Forschungszentrum Jülich in Germany. The first objective of this project is to establish where air within the double tropopause originates since it could change the composition of the UTLS and thus Earth's radiative budget. The second objective is to understand the relationship between the double tropopause and tropopause inversion layer (TIL), a relationship recently put forth by other scientists using a dry-atmosphere model. That study found that the double tropopause could not form without the TIL being present. This connection is unexpected since these two atmospheric features have opposite spatial preferences and seasonal cycles, thus observations with high vertical resolution and a model specialized for the UTLS will be used to explore this relationship.Another benefit of this project, in addition to an increased understanding of the UTLS region and Earth's climate, includes the exchange of expertise between the PI and the host institution in Germany. Dr. Peevey will benefit greatly from the exchange by gaining knowledge of lagrangian models and skills in running model simulations.