Performance of a multi-RCM ensemble for South Eastern South America   总被引：1，自引：1，他引：0  

A. F. Carril  C. G. Menéndez  A. R. C. Remedio  F. Robledo  A. S?rensson  B. Tencer  J.-P. Boulanger  M. de Castro  D. Jacob  H. Le Treut  L. Z. X. Li  O. Penalba  S. Pfeifer  M. Rusticucci  P. Salio  P. Samuelsson  E. Sanchez  P. Zaninelli 《Climate Dynamics》2012,39(12):2747-2768

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.  相似文献   

The impact of soil moisture–atmosphere coupling on daily maximum surface temperatures in Southeastern South America     

Coronato  Tanea  Carril  Andrea F.  Zaninelli  Pablo G.  Giles  Julián  Ruscica  Romina  Falco  Magdalena  Sörensson  Anna A.  Fita  Lluis  Li  Laurent Z. X.  Menéndez  Claudio G. 《Climate Dynamics》2020,55(9-10):2543-2556

Based on a series of experiments conducted by two regional climate models (RCA4 and LMDZ) with and without soil moisture-atmosphere coupling, we investigate the role of soil moisture on the occurrence of surface air temperature extremes and its persistence in Southeastern South America. Our analysis reveals that both factors, soil moisture-atmosphere coupling and relatively drier soil conditions, enhance the temperature extremes. In addition, the existence of soil-atmosphere coupling and the associated soil moisture variability is crucial for the development of the extremes in SESA. The key role of soil-atmosphere coupling is also reflected in the intrinsic persistence of hot days, which is greater in simulations with interactive soil moisture than in those with prescribed soil conditions. In the absence of soil-atmosphere coupling, the imprint of the anomalous dry (and also wet) soil conditions on the intensity and persistence of hot days is weaker.

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