• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >The response of stratospheric water vapor to a changing climate: Insights from in situ water vapor measurements.
【24h】

The response of stratospheric water vapor to a changing climate: Insights from in situ water vapor measurements.

机译：平流层水汽对气候变化的响应：原位水汽测量的见解。

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

Stratospheric water vapor plays an important role in the Earth system, both through its role in stratospheric ozone destruction and as a greenhouse gas contributing to radiative forcing of the climate. Highly accurate water vapor measurements are critical to understanding how stratospheric water vapor concentrations will respond to a changing climate. However, the past disagreement among water vapor instruments on the order of 1--2 ppmv hinders understanding of the mechanisms which control stratospheric humidity, and the reliable detection of water vapor trends.;In response to these issues, we present a new dual axis water vapor instrument that combines the heritage Harvard Lyman-alpha hygrometer with the newly developed Harvard Herriott Hygrometer (HHH). The Lyman-alpha instrument utilizes ultraviolet photo-fragment fluorescence detection, and its accuracy has been demonstrated though rigorous laboratory calibrations and in situ diagnostic procedures. HHH employs a tunable diode near-IR laser to measure water vapor via direct absorption in a Herriott cell; it demonstrated in-flight precision of 0.1 ppmv (1-sec) with accuracy of 5%+/-0.5 ppmv. We describe these two measurement techniques in detail along with our methodology for calibration and details of the measurement uncertainties. We also examine the recent flight comparison of the two instruments with several other in situ hygrometers during the 2011 MACPEX campaign, in which five independent instruments agreed to within 0.7 ppmv, a significant improvement over past comparisons.;Water vapor measurements in combination with simultaneous in situ measurements of O3, CO, CO2, HDO, and HCl are also used to investigate transport in the Tropical Tropopause Layer (TTL). Data from the winter 2006 CR-AVE campaign and the summer 2007 TC4 campaign are analyzed in a one-dimensional mixing model to explore the seasonal importance of transport within the TTL via slow upward ascent, convective injection, and isentropic transport from the midlatitude stratosphere. The model shows transport from midlatitudes to be significant in summer and winter, affecting ozone concentrations and therefore the radiative balance of the TTL. It also shows significant convective influence up to 420 K potential temperature in both seasons, which appreciably increases the amount of water vapor above the tropopause.
机译：平流层水蒸气通过其在平流层臭氧破坏中的作用以及作为导致气候辐射强迫的温室气体而在地球系统中发挥着重要作用。高度准确的水蒸气测量对于了解平流层水蒸气浓度将如何响应气候变化至关重要。但是，过去水蒸气仪器之间在1--2 ppmv数量级上的分歧阻碍了对控制平流层湿度的机制以及水蒸气趋势的可靠检测的理解。；针对这些问题，我们提出了一个新的双轴结合了传统的哈佛莱曼α湿度计和新开发的哈佛Herriott湿度计（HHH）的水蒸气仪。 Lyman-alpha仪器利用紫外光碎裂荧光检测，通过严格的实验室校准和原位诊断程序证明了其准确性。 HHH使用可调二极管近红外激光器通过直接在Herriott池中吸收来测量水蒸气。它的飞行精度为0.1 ppmv（1秒），精度为5％+ /-0.5 ppmv。我们将详细介绍这两种测量技术，以及校准方法和测量不确定度的详细信息。我们还研究了2011年MACPEX活动期间这两种仪器与其他几台原位湿度计的近期飞行比较，其中五台独立仪器的误差在0.7 ppmv之内，与过去的比较相比有显着改进。 O3，CO，CO2，HDO和HCl的原位测量也用于调查热带对流层（TTL）中的传输。在一个一维混合模型中分析了2006年冬季CR-AVE活动和2007年夏季TC4活动的数据，以探索通过中纬度平流层缓慢向上上升，对流注入和等熵传输在TTL内传输的季节性重要性。该模型显示，夏季和冬季从中纬度的运输非常重要，影响了臭氧浓度，因此影响了TTL的辐射平衡。在两个季节中，它还显示出对流影响，最高可达420 K的潜在温度，这明显增加了对流层顶上方的水蒸气量。

著录项

  • 作者

    Sargent, Maryann Racine.;

  • 作者单位

    Harvard University.;

  • 授予单位 Harvard University.;
  • 学科 Atmospheric sciences.;Environmental science.;Atmospheric chemistry.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 148 p.
  • 总页数 148
  • 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