TY - JOUR
T1 - Daily precipitation statistics in regional climate models
T2 - Evaluation and intercomparison for the European Alps
AU - Frei, Christoph
AU - Christensen, Jens Hesselbjerg
AU - Déqué, Michel
AU - Jacob, Daniela
AU - Jones, Richard G.
AU - Vidale, Pier Luigi
PY - 2003/2/16
Y1 - 2003/2/16
N2 - An evaluation is undertaken of the statistics of daily precipitation as simulated by five regional climate models using comprehensive observations in the region of the European Alps. Four limited area models and one variable-resolution global model are considered, all with a grid spacing of 50 km. The 15-year integrations were forced from reanalyses and observed sea surface temperature and sea ice (global model from sea surface only). The observational reference is based on 6400 rain gauge records (10-50 stations per grid box). Evaluation statistics encompass mean precipitation, wet-day frequency, precipitation intensity, and quantiles of the frequency distribution. For mean precipitation, the models reproduce the characteristics of the annual cycle and the spatial distribution. The domain mean bias varies between -23% and +3% in winter and between -27% and -5% in summer. Larger errors are found for other statistics. In summer, all models underestimate precipitation intensity (by 16-42%) and there is a too low frequency of heavy events. This bias reflects too dry summer mean conditions in three of the models, while it is partly compensated by too many low-intensity events in the other two models. Similar intermodel differences are found for other European subregions. Interestingly, the model errors are very similar between the two models with the same dynamical core (but different parameterizations) and they differ considerably between the two models with similar parameterizations (but different dynamics). Despite considerable biases, the models reproduce prominent mesoscale features of heavy precipitation, which is a promising result for their use in climate change downscaling over complex topography.
AB - An evaluation is undertaken of the statistics of daily precipitation as simulated by five regional climate models using comprehensive observations in the region of the European Alps. Four limited area models and one variable-resolution global model are considered, all with a grid spacing of 50 km. The 15-year integrations were forced from reanalyses and observed sea surface temperature and sea ice (global model from sea surface only). The observational reference is based on 6400 rain gauge records (10-50 stations per grid box). Evaluation statistics encompass mean precipitation, wet-day frequency, precipitation intensity, and quantiles of the frequency distribution. For mean precipitation, the models reproduce the characteristics of the annual cycle and the spatial distribution. The domain mean bias varies between -23% and +3% in winter and between -27% and -5% in summer. Larger errors are found for other statistics. In summer, all models underestimate precipitation intensity (by 16-42%) and there is a too low frequency of heavy events. This bias reflects too dry summer mean conditions in three of the models, while it is partly compensated by too many low-intensity events in the other two models. Similar intermodel differences are found for other European subregions. Interestingly, the model errors are very similar between the two models with the same dynamical core (but different parameterizations) and they differ considerably between the two models with similar parameterizations (but different dynamics). Despite considerable biases, the models reproduce prominent mesoscale features of heavy precipitation, which is a promising result for their use in climate change downscaling over complex topography.
KW - Alps
KW - Climate change downscaling
KW - Climate model evaluation
KW - Extreme events
KW - Heavy precipitation
UR - http://www.scopus.com/inward/record.url?scp=0042231792&partnerID=8YFLogxK
M3 - Journal article
AN - SCOPUS:0042231792
SN - 2169-8953
VL - 108
JO - Journal of Geophysical Research D: Atmospheres
JF - Journal of Geophysical Research D: Atmospheres
IS - 3
ER -
