• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Martian global dust storm 2001A as observed by the Mars Global Surveyor Thermal Emission Spectrometer.
【24h】

Martian global dust storm 2001A as observed by the Mars Global Surveyor Thermal Emission Spectrometer.

机译：火星全球测量师热发射光谱仪观测到的火星全球沙尘暴2001A。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The purpose of this work is to study the general characteristics of Martian global dust storms, and their relation to the Martian dust cycle using infrared observations. I devised a parameter retrieval algorithm for Mars Global Surveyor Thermal Emission Spectrometer daytime data from global dust storm 2001A that extracts information about dust optical depth, effective radius, and surface temperature using Newtonian first-order sensitivity functions of the infrared spectrum in response to variations in these parameters. This algorithm is both relatively accurate and very fast, successfully retrieving parameters from 56878 spectra for global dust storm 2001A, as well as a subsequent Martian year in comparison. There are uncertainties introduced into the retrievals, especially by parameters that could not be constrained such as the optical constants of the Martian dust. Uncertainties in assumed vertical mixing of dust can lead to significant uncertainties in retrieved optical depth and dust effective radius. I discovered several aspects of the dust storm that have not previously been recognized. One of these is that the dust optical depth becomes correlated with surface pressure during the decay phase of the dust storm. Similar pressure optical depth correlations were found the following Martian year when no global dust storm occurred. Global correlation of dust optical depth and surface pressure, indicative of global dust mixing processes, also varies with the season. It is generally larger during southern hemisphere late spring and summer, and very low at all other seasons when there is no global dust storm. These pressure and optical depth data provide a tool to study atmospheric dynamics. I also found that the observed decay of optical depths at the later stages of the dust storm match, to first order, theoretical values of clearing from Stokes-Cunningham fallout of the dust. The unprecedented coverage of the retrieval of dust effective radii allowed me to discover previously unseen global trends. Zonally averaged effective radius is constant, within uncertainties, at all latitudes and seasons except at high southern latitudes around equinoxes in both Martian years, where it is larger than average. The emergence and disappearance of these larger particles correlates with observations of polar cap edge storms at those latitudes. Northern latitude observations under similar conditions yielded systematically lower average effective radii. I also discovered a previously unreported linear correlation between daytime surface temperature drop and rise in optical depth during the global dust storm. Global dust storm 2001A produced a significant optical depth and surface temperature anomaly in the dust cycle that was responsible for abating local dust storms. The observations of trends in effective radii are significantly different from trends predicted by global circulation models and need to be accounted for in future studies.
机译：这项工作的目的是使用红外观测来研究火星全球沙尘暴的一般特征及其与火星沙尘循环的关系。我为来自全球沙尘暴2001A的火星全球测量师热发射光谱仪白天数据设计了一种参数检索算法，该算法利用红外光谱的牛顿一阶敏感函数提取与尘埃光学深度，有效半径和表面温度有关的信息，以响应温度变化。这些参数。此算法相对准确且非常快速，可以成功地从2001878年全球沙尘暴以及随后的火星年度比较的56878个光谱中检索出参数。检索中引入了不确定性，特别是受到诸如火星尘埃的光学常数之类不受约束的参数的影响。假定的垂直粉尘混合的不确定性可能导致所获取的光学深度和粉尘有效半径的显着不确定性。我发现了沙尘暴的几个以前没有认识到的方面。其中之一是，在沙尘暴的衰减阶段，尘埃光学深度与表面压力相关。在次年火星年未发生全球沙尘暴时，发现了相似的压力光学深度相关性。尘埃光学深度和表面压力的全球相关性（表示全球尘埃混合过程）也随季节而变化。在春季和夏季末的南半球，它通常较大，而在没有全球沙尘暴的其他所有季节中，它都非常低。这些压力和光学深度数据提供了研究大气动力学的工具。我还发现，在沙尘暴后期，观测到的光学深度衰减与一阶斯托克斯-坎宁安尘埃清除尘埃的理论值相符。尘埃有效半径检索的空前覆盖使我得以发现以前看不见的全球趋势。在所有纬度和季节，区域平均有效半径均是恒定的，在不确定性范围内，但在火星的两个年份均高于春分点附近的南部高纬度地区，该半径均大于平均值。这些较大粒子的出现和消失与在这些纬度的极地帽边缘风暴的观测有关。在类似条件下进行的北纬观测系统地降低了平均有效半径。我还发现了全球沙尘暴期间白天表面温度下降和光学深度上升之间以前没有报道的线性相关性。全球沙尘暴2001A在尘埃循环中产生了明显的光学深度和表面温度异常，这是减弱局部沙尘暴的原因。有效半径趋势的观测结果与全球环流模型预测的趋势显着不同，需要在以后的研究中加以考虑。

著录项

  • 作者

    Elteto, Attila.;

  • 作者单位

    University of Colorado at Boulder.;

  • 授予单位 University of Colorado at Boulder.;
  • 学科 Physics Astronomy and Astrophysics.;Remote Sensing.;Atmospheric Sciences.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 198 p.
  • 总页数 198
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号