• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Hydrological and Biogeochemical Modeling of Taylor Valley Lakes, East Antarctica.
【24h】

Hydrological and Biogeochemical Modeling of Taylor Valley Lakes, East Antarctica.

机译：南极东部泰勒谷湖的水文和生物地球化学模拟。

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

This research is focused on better understanding of past and present hydrological and biological sensitivity of perennially ice-covered lakes in Taylor Valley, McMurdo Dry Valleys, East Antarctica, with respect to changes in climate, summarized in three distinct chapters.;Glacial Lake Washburn was present in Taylor Valley during the Last Glacial Maximum (LGM), despite a significantly cooler climate. Contemporary anomalous warm summer westerly winds are responsible for generating a large volume of melt water during the short austral summers by increasing the degree days above freezing. The high frequency of westerly winds during the LGM was responsible for the formation of large glacial lakes during the LGM. Data from a nearby Taylor Dome ice core record supports windier conditions and a link between Taylor Dome and Taylor Valley was established. However, the surface air temperature increase due to the westerly winds is not preserved in the annually averaged ice core record. Yet, it was the seasonal warming due to increased frequency of anomalous summer winds that contributed to the GLW formation. This analysis suggests that summer air temperature during the LGM were as warm as today.;An autonomous underwater vehicle was deployed under the thick ice cover of West Lobe of Lake Bonney, generating a high-resolution, spatially distributed biogeochemical and physical dataset. Ice thickness varied depending on shading from nearby mountains and sediment accumulation on the surface of the ice. Spatial ice thickness variations controlled available underwater photosynthetically active radiation (PAR) and chlorophyll-a distribution. PAR was negatively correlated with chlorophyll-a, which was attributed to short-term photoadaptation of phytoplanktonic communities.;Ice thicknesses of perennially ice-covered lakes in Taylor Valley were modeled utilizing a one-dimensioned heat equation coupled with the atmosphere and the underlying water column. The long-term ice thickness trends are strongly controlled by the heat content of a lake. Deep lakes with deep-water temperature maximum will either hinder or facilitate ice thickness growth or decay due to the heat flux from below. Shallow lakes are more responsive to climatic changes. Future ice thickness predictions suggest that ice covers of perennially ice-covered lakes can become seasonally ice-free within couple decades.
机译：这项研究的重点是更好地了解南极东部麦克默多干旱谷泰勒山谷常年覆冰的湖泊过去和现在的水文和生物学敏感性，并在气候变化方面进行了概括，共分三章。尽管气候明显凉爽，但在上一次冰川最大期（LGM）期间仍存在于泰勒谷。当代短时温暖的夏季西风异常通过增加高于冰冻天数的时间在短短的夏季产生大量的融水。 LGM期间西风的高频率是LGM期间大型冰川湖形成的原因。来自附近的泰勒圆顶冰芯记录的数据支持多风条件，并建立了泰勒圆顶和泰勒谷之间的联系。但是，由于西风造成的地表气温升高并未保留在年平均冰芯记录中。然而，正是由于夏季风异常频率增加导致的季节性变暖才导致了GLW的形成。该分析表明，LGM期间的夏季气温与今天一样温暖。；一辆自动水下车辆被部署在邦尼湖西洛布的厚厚的冰盖下，生成了高分辨率的，空间分布的生物地球化学和物理数据集。冰层厚度的变化取决于附近山脉的阴影和冰面上沉积物的堆积。空间冰厚度的变化控制着水下可用的光合有效辐射（PAR）和叶绿素a的分布。 PAR与叶绿素a负相关，这归因于浮游植物群落的短期光适应。柱。冰的长期趋势受湖泊热量的强烈控制。由于来自下方的热通量，深水温度最高的深湖将阻碍或促进冰厚度的增长或衰减。浅水湖泊对气候变化反应更快。未来的冰厚预测表明，常年被冰覆盖的湖泊的冰盖可能在几十年内变得季节性无冰。

著录项

  • 作者

    Obryk, Maciej Krzysztof.;

  • 作者单位

    University of Illinois at Chicago.;

  • 授予单位 University of Illinois at Chicago.;
  • 学科 Limnology.;Hydrologic sciences.;Biology.
  • 学位 Ph.D.
  • 年度 2014
  • 页码 128 p.
  • 总页数 128
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 遥感技术;
  • 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