Implementation and evaluation of WRF simulation over a city with complex terrain using Alos-Palsar 0.4 s topography

Area of Science:

• Environmental science
• Atmospheric science
• Geographic information science

Background:

• Accurate meteorological modeling is crucial for urban air quality assessments, especially in complex topography.
• Standard Weather Research and Forecast (WRF) models often use default elevation data (GTOPO30s) which may limit accuracy in challenging terrains.
• Bogotá, Colombia, situated in the Andes Mountains at 2600m, presents a unique case for evaluating meteorological model performance due to its complex topography.

Purpose of the Study:

• To evaluate the performance of the Alos-Palsar 0.4s global digital elevation model (GDEM) within the WRF model for simulating meteorology in Bogotá.
• To compare the accuracy of meteorological simulations using Alos-Palsar 0.4s topography against the standard GTOPO30s data.
• To establish a reliable and accurate method for meteorological simulation in complex urban environments for air quality modeling.

Main Methods:

• Utilized the WRF model with two domain configurations at 1000m horizontal spatial resolution.
• Incorporated Alos-Palsar 0.4s GDEM data as an alternative to the default GTOPO30s elevation data.
• Performed quantitative evaluations using Index of Agreement (IOA), Pearson correlation coefficient (r), Root Mean Square Error (RMSE), Mean Gross Error (MGE), and Mean Bias (MB) for temperature, humidity, wind, and solar radiation.
• Employed Taylor diagrams for comprehensive visual evaluation.

Main Results:

• Identified spatial differences between Alos-Palsar 0.4s and GTOPO30s elevation data in Bogotá.
• Simulations using Alos-Palsar 0.4s topography demonstrated significant improvements in meteorological representation compared to GTOPO30s.
• Quantitative and qualitative evaluations indicated enhanced accuracy in simulating key meteorological variables.

Conclusions:

• The Alos-Palsar 0.4s GDEM offers a substantial improvement for meteorological simulations in complex terrains like Bogotá when used with the WRF model.
• This enhanced topographical data contributes to more reliable air quality modeling in urban areas with challenging geographical features.
• The study validates the use of higher-resolution GDEM data for improving atmospheric simulations in specific geographical contexts.