首页> 外文学位 >Some aspects of the Martian climate in the Mars Orbiter Laser Altimeter (MOLA) investigation. Part I. Evolution of the polar residual ice caps. Part II. Polar night clouds. Part III. Interpretation of the MOLA reflectivity measurement in terms of the surface albedo and atmospheric opacity.
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Some aspects of the Martian climate in the Mars Orbiter Laser Altimeter (MOLA) investigation. Part I. Evolution of the polar residual ice caps. Part II. Polar night clouds. Part III. Interpretation of the MOLA reflectivity measurement in terms of the surface albedo and atmospheric opacity.

机译:火星轨道激光高度计(MOLA)研究中的火星气候某些方面。第一部分。极地残余冰盖的演变。第二部分极夜云。第三部分用表面反照率和大气不透明度解释MOLA反射率的测量结果。

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摘要

The spacecraft exploration of the planet Mars in the last two decades provided scientists with an enormously rich data base. This work presents some aspects of the Mars Orbiter Laser Altimeter investigation related to the issues in the Martian climatology. The instrument continues to function on board of the Mars Global Surveyor Spacecraft.;The polar ice caps on Mars are the largest reservoirs of water on the planet. Their formation and evolution are not understood very well at this point. Ice flow, sublimation and wind erosion are believed to be the most important processes that shape the caps. We have developed a model to understand the role of sublimation for the formation of the ice caps and attempted to constrain the time scale for the formation of the observed ice caps. We argue that sublimation is a very important process for the formation of the caps, especially on the time scales greater than 10 million years.;We report the direct observations of CO2 clouds, forming during the polar winter times over both poles. These clouds are similar over both poles and possibly represent a CO 2 snowfall. On the basis of the reflective properties and spatial occurrence, we can distinguish two major classes of clouds. We will discuss some hypotheses on the mechanisms of their formation.;Total atmospheric opacity of the Martian atmosphere at 1mu m can be derived from the MOLA reflectivity measurement. Opacity estimates are found to be consistent with the Viking Lander and Pathfinder values. Opacity measured in the polar regions displays storms and polar hood activity. We will derive scale heights for dust and water ice using observations on large topographic structures. Comparison of the MOLA derived opacity with the TES derived opacity yields information on the aerosol particle size distribution. We discuss an algorithm to derive 1mum normal albedo of the surface. 9mum dust opacity from the Thermal Emission Spectrometer (TES) is employed to remove an atmospheric attenuation from the MOLA reflectivity measurements. We will present some initial results on the calculation of the surface albedo.
机译:在过去的二十年中,对火星的航天器探索为科学家提供了极为丰富的数据库。这项工作介绍了有关火星气候学问题的火星轨道激光高度计研究的某些方面。该仪器继续在火星全球测量员航天器上运行。;火星上的极地冰盖是地球上最大的水库。在这一点上,它们的形成和演化还不太清楚。冰流,升华和风蚀被认为是塑造瓶盖的最重要过程。我们开发了一个模型来了解升华对冰盖形成的作用,并试图限制观察到的冰盖形成的时间尺度。我们认为升华是形成顶盖的一个非常重要的过程,尤其是在大于一千万年的时间尺度上。我们报告了在两极的极地冬季形成的二氧化碳云的直接观测结果。这些云在两个极点上都相似,并且可能表示CO 2降雪。根据反射特性和空间出现情况,我们可以区分出两大类云。我们将讨论有关其形成机理的一些假设。可以从MOLA反射率测量中得出火星大气在1μm处的总大气不透明度。发现不透明度估计值与Viking Lander和Pathfinder值一致。在极地地区测得的不透明度会显示风暴和极地罩活动。我们将使用对大型地形结构的观测来得出灰尘和水冰的标尺高度。将MOLA衍生的不透明度与TES衍生的不透明度进行比较,可得出有关气溶胶粒径分布的信息。我们讨论了一种导出表面1mum法线反照率的算法。使用热发射光谱仪(TES)测得的9mum灰尘不透明性可从MOLA反射率测量结果中消除大气衰减。我们将介绍一些有关表面反照率计算的初步结果。

著录项

  • 作者

    Ivanov, Anton Borisovich.;

  • 作者单位

    California Institute of Technology.;

  • 授予单位 California Institute of Technology.;
  • 学科 Geophysics.;Physics Astronomy and Astrophysics.;Physics Atmospheric Science.
  • 学位 Ph.D.
  • 年度 2002
  • 页码 137 p.
  • 总页数 137
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 11:46:18

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