...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Climate dynamics >Simulations of precipitation using NRCM and comparisons with satellite observations and CAM: annual cycle
【24h】

Simulations of precipitation using NRCM and comparisons with satellite observations and CAM: annual cycle

机译：利用NRCM模拟降水，并与卫星观测和CAM进行比较：年周期

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 accurate representation of rainfall in models of global climate has been a challenging task for climate modelers owing to its small space and time scales. Quantifying this variability is important for comparing simulations of atmospheric behavior with real time observations. In this regard, this paper compares both the statistical and dynamically forced aspects of precipitation variability simulated by the high-resolution (36 km) Nested Regional Climate Model (NRCM), with satellite observations from the Tropical Rainfall Measuring Mission (TRMM) 3B42 dataset and simulations from the Community Atmosphere Model (CAM) at T85 spatial resolution. Six years of rainfall rate data (2000-2005) from within the Tropics (30°S-30°N) have been used in the analysis and results are presented in terms of long-term mean rain rates, amplitude and phase of the annual cycle and seasonal mean maps of precipitation. Our primary focus is on characterizing the annual cycle of rainfall over four land regions of the Tropics namely, the Indian Monsoon, the Amazon, Tropical Africa and the North American monsoon. The lower tropospheric circulation patterns are analyzed in both the observations and the models to identify possible causes for biases in the simulated precipitation. The 6-year mean precipitation simulated by both models show substantial biases throughout the global Tropics with NRCM/CAM systematically underestimating/overestimating rainfall almost everywhere. The seasonal march of rainfall across the equator, following the motion of the sun, is clearly seen in the harmonic vector maps. The timing of peak rainfall (phase) produced by NRCM is in closer agreement with the observations compared to CAM. However like the longtime mean, the magnitude of seasonal mean rainfall is greatly underestimated by NRCM throughout the Tropical land mass. Some of these regional biases can be attributed to erroneous circulation and moisture surpluses/deficits in the lower troposphere in both models. Overall, the results seem to indicate that employing a higher spatial resolution (36 km) does not significantly improve simulation of precipitation. We speculate that a combination of several physics parameterizations and lack of model tuning gives rise to the observed differences between NRCM and the observations.
机译：由于其空间和时间尺度小，在全球气候模型中准确表示降雨对气候建模者来说是一项艰巨的任务。量化这种可变性对于比较大气行为模拟与实时观测非常重要。在这方面，本文将高分辨率（36 km）嵌套区域气候模型（NRCM）模拟的降水变化的统计和动态强迫方面与热带降雨测量任务（TRMM）3B42数据集和卫星观测数据进行了比较。来自T85空间分辨率的社区大气模型（CAM）的模拟。来自热带地区（30°S-30°N）的六年降雨率数据（2000-2005年）已用于分析，结果以长期平均降雨率，年幅和年相表示。降水的周期图和季节平均图。我们的主要重点是描述热带四个陆地区域，即印度季风，亚马逊，热带非洲和北美季风的年降水量周期。在观测值和模型中都分析了较低的对流层环流模式，以找出模拟降水中偏差的可能原因。两种模式模拟的6年平均降水量在整个热带地区都显示出很大的偏差，而NRCM / CAM系统地估计/高估了几乎所有地方的降雨量。在谐波矢量图中可以清楚地看到随着太阳的运动，整个赤道的季节性降雨行进。与CAM相比，NRCM产生的峰值降雨（阶段）的时间与观测值更接近。但是，像长期平均值一样，整个热带陆地上的NRCM大大低估了季节平均降雨量的大小。在这两个模型中，这些区域性偏见中的一些都可归因于对流层下部的错误循环和水分过剩/不足。总的来说，结果似乎表明采用更高的空间分辨率（36 km）并不能显着改善降水的模拟。我们推测，几种物理参数化和缺乏模型调整的结合会导致NRCM与观测值之间的观测差异。

著录项

  • 来源
    《Climate dynamics》 |2011年第10期|p.1659-1679|共21页
  • 作者

    Aditya Murthi; Kenneth P. Bowman; L. Ruby Leung;

  • 作者单位

    Department of Atmospheric Sciences, Texas A&M Univers 3150 TAMU, College Station, TX 77843, USA;

    Department of Atmospheric Sciences, Texas A&M Univers 3150 TAMU, College Station, TX 77843, USA;

    Pacific Northwest National Laboratory, PO Box 999, MSIN: K9-24, Richland, WA 99352, USA;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    precipitation; annual cycle; NRCM; CAM;

    机译：沉淀;年度周期;NRCM;凸轮;

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