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Title: Using Integrated EOF Analysis for Evaluation of WRF Simulations in Urban Environments
Abstract Evaluation methods for Regional Climate Models (RCMs) commonly rely on point comparisons with observed meteorological fields, which provide limited understanding of the spatial and temporal representation of important factors affecting urban areas in models. These factors are not only complex but also difficult to differentiate, which complicates their analysis. This study thus develops an innovative approach using Empirical Orthogonal Function (EOF) analysis to compare urban heat island and precipitation patterns in RCM simulations with those from observations, taking advantage of the capacity of the method for data disaggregation. The method was tested on summer daily maximum and minimum temperature (Tmaxand Tmin) and precipitation (P) in the Chicago Metro Area (CMA). Using observed data, the EOF analysis on temperature consistently produced coherent patterns that reflect known impacts of urban environments on climate and weather. EOF evaluation of corresponding 4-km WRF simulations against observations confirmed a strong warm bias (~3°C) for simulated Tminin the urban area, as observed in point comparisons against stations; further analysis, however, suggested that the shape and time behavior of the urban pattern were well represented. EOF analysis on Tmax, which showed no problems in the point comparison, revealed important differences in shape (urban area of influence on temperatures) and time [Principal Components (PC) correlation of −0.5] for the urban pattern between datasets, suggesting the need for model improvements. Results showed no systematic urban effects on summer P for the CMA for observations or simulations, but analysis of winter patterns suggested a possible urban enhancement on P over the city.  more » « less
Award ID(s):
2139316
PAR ID:
10665305
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
AMS
Date Published:
Journal Name:
Journal of Applied Meteorology and Climatology
ISSN:
1558-8424
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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