A schematic chart illustrates climate model evaluation with the MVIETooL. Credit: ZHANG Mengzhuo

The multivariable integrated evaluation (MVIE) method can help meteorologists to quantitatively evaluate the overall performance of a climate model in simulating multiple variables like air temperature, precipitation, and vector wind, against observed ones.

Recently, researchers from Nanjing University and the Institute of Atmospheric Âé¶¹ÒùÔºics (IAP) of the Chinese Academy of Sciences developed a simple-to-use Multivariable Integrated Evaluation Tool (MVIETool) coded with Python/NCL to facilitate climate evaluation and models inter-comparison, improving the MVIE method.

The study was published in Geoscientific Model Development on May 28.

"The improved MVIE method can provide a more comprehensive and precise evaluation of climate model performance. With the support of the MVIETool, one can easily evaluate model performance in terms of each individual variable and/or multiple variables," said Zhang Mengzhuo from the School of Atmospheric Sciences, Nanjing University, the first author of the study.

In the improved method, the area-weighting is taken into the definition of statistics in MVIE, which makes the evaluation results of spatial fields more accurate. "The method allows a mixed evaluation of scalar and vector fields," said Prof. Xu Zhongfeng from IAP, the corresponding author of the study. "A multivariable integrated skill score is proposed as a flexible and normalized index to quantitatively measure a model's ability to simulate multiple fields."

In addition to model evaluation, the improved MVIE method may also be applied to other areas, e.g., . One may use the MVIE method to measure the overall accuracy of multiple variables generated by a machine learning model relative to the target values.

More information: Meng-Zhuo Zhang et al, An improved multivariable integrated evaluation method and tool (MVIETool) v1.0 for multimodel intercomparison, Geoscientific Model Development (2021).