Performance of a multi-RCM ensemble for South Eastern South America
Performance of a multi-RCM ensemble for South Eastern South America
复制标题
DOI：
10.1007/s00382-012-1573-z
复制
发表时间：
2012-10
期刊：
影响因子：
4.6
通讯作者：
A. Carril;C. Menéndez;A. Remedio;F. Robledo;A. Sörensson;B. Tencer;J. Boulanger;M. Castro;D. Jacob;H. Treut;L. Li;O. Penalba;S. Pfeifer;M. Rusticucci;P. Salio;P. Samuelsson;E. Sánchez;P. Zaninelli
中科院分区：
文献类型：
--
作者：
A. Carril;C. Menéndez;A. Remedio;F. Robledo;A. Sörensson;B. Tencer;J. Boulanger;M. Castro;D. Jacob;H. Treut;L. Li;O. Penalba;S. Pfeifer;M. Rusticucci;P. Salio;P. Samuelsson;E. Sánchez;P. Zaninelli
本文以拉普拉塔盆地为重点，检验了四个区域气候模式再现当今南美洲气候的能力。1991-2000年期间的模型与ERA-40再分析的初始和横向边界条件相结合。集合海平面气压，最高和最低温度和降水的季节平均值和极端指数的基础上百分位的方法进行评估。此外，还讨论了模式间的离散性以及在不同气候条件下比较集合平均值时的不确定性。总体平均值比南美洲东南部（SESA）的观测值更温暖，特别是对于冬季最低温度，误差的大小朝着分布的尾部增加。集合平均再现了降水的广泛的空间格局，但高估了热带地区的对流降水和沿着安第斯山脉和巴西高地的地形降水，低估了季风核心区附近的降水。该模型高估了潮湿的天数，低估了两个季节的每日降雨强度，这表明对流的过早触发。模拟SESA夏季对流降水强度和与强降水事件（上四分位数日降水）相关的变率的模式技能远远不能令人满意。由于观测网络的稀疏性，对于某些地区和季节，季节平均值的集合和观测不确定性是相当的。
The ability of four regional climate models to reproduce the present-day South American climate is examined with emphasis on La Plata Basin. Models were integrated for the period 1991–2000 with initial and lateral boundary conditions from ERA-40 Reanalysis. The ensemble sea level pressure, maximum and minimum temperatures and precipitation are evaluated in terms of seasonal means and extreme indices based on a percentile approach. Dispersion among the individual models and uncertainties when comparing the ensemble mean with different climatologies are also discussed. The ensemble mean is warmer than the observations in South Eastern South America (SESA), especially for minimum winter temperatures with errors increasing in magnitude towards the tails of the distributions. The ensemble mean reproduces the broad spatial pattern of precipitation, but overestimates the convective precipitation in the tropics and the orographic precipitation along the Andes and over the Brazilian Highlands, and underestimates the precipitation near the monsoon core region. The models overestimate the number of wet days and underestimate the daily intensity of rainfall for both seasons suggesting a premature triggering of convection. The skill of models to simulate the intensity of convective precipitation in summer in SESA and the variability associated with heavy precipitation events (the upper quartile daily precipitation) is far from satisfactory. Owing to the sparseness of the observing network, ensemble and observations uncertainties in seasonal means are comparable for some regions and seasons.