...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Combined measurements of ~(17)O_(excess) and d-excess in African monsoon precipitation: Implications for evaluating convective parameterizations
【24h】

Combined measurements of ~(17)O_(excess) and d-excess in African monsoon precipitation: Implications for evaluating convective parameterizations

机译：非洲季风降水中〜（17）O_（过量）和d-过量的组合测量：对流参数化评估的意义

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

Water stable isotopes (δ~(18)O, δD) are useful tools to depict and to understand the atmospheric water cycle. In tropical regions, they record the variations of convective activity and their implementation in convection schemes brings constraints on our understanding and parameterization of this phenomena. Here, we present for the first time measurements of a new isotopic marker of the hydrological cycle (~(17)O_(excess) resulting from the combination of δ~(17)O and δ~(18)O of water) in convective regions on two different time scales: (i) during the African monsoon onset and intra-seasonal variability (Banizoumbou, 2006) and (ii) during the squall line of the 11th of August 2006 (Niamey). ~(17)O_(excess) responds to the monsoon onset by a ~30 per meg increase as well as to different convective processes in squall lines by ~20 per meg variations. These variations parallel those of d-excess at first order and display significant correlation with relative humidity in the lower troposphere. Still, higher correlation coefficients are observed between d-excess and relative humidity than between ~(17)O_(excess) and relative humidity, suggesting a higher influence of relative humidity on d-excess than on ~(17)O_(excess). Using a simple reevaporation model and a more sophisticated 2D model of a squall line, we show that reevaporation is the process explaining the increase of d-excess and ~(17)O_(excess) with relative humidity for these two studies. We also show that the combination of ~(17)O_(excess) and d-excess is a powerful tool to constrain the representation of isotopic processes during rain reevaporation. In turn, a good representation of such processes enables to use water isotopes to evaluate convective parameterization in atmospheric models.
机译：水稳定同位素（δ〜（18）O，δD）是描述和理解大气水循环的有用工具。在热带地区，他们记录了对流活动的变化，在对流方案中的实施给我们对这种现象的理解和参数化带来了限制。在这里，我们首次提出了对流过程中新的水文同位素标记（〜（17）O_（过量），是水的δ〜（17）O和δ〜（18）O的组合）区域在两个不同的时间尺度上：（i）在非洲季风爆发和季节内变化期间（Banizoumbou，2006）和（ii）在2006年8月11日的线（尼亚美）期间。 〜（17）O_（过量）对季风发作的响应是每兆度增加〜30，并且对qua线中的不同对流过程的响应是每兆变差〜20。这些变化与一阶d过量的变化平行，并显示出与对流层下部相对湿度的显着相关性。尽管如此，在d过量和相对湿度之间观察到的相关系数高于〜（17）O_（过量）和相对湿度之间的相关系数，这表明相对湿度对d-过量的影响要大于对〜（17）O_（过量）的影响。使用简单的再蒸发模型和and线的更复杂的2D模型，我们显示这两个研究都证明再蒸发是d-过量和〜（17）O_（过量）随着相对湿度增加的过程。我们还表明，〜（17）O_（excess）和d-excess的组合是一个强大的工具，可以限制雨水在再蒸发过程中同位素过程的表示。反过来，此类过程的良好表示形式使得可以使用水同位素来评估大气模型中的对流参数化。

著录项

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