Home » High-resolution atmospheric simulation helps forecast heavy summer rainfall and floods

High-resolution atmospheric simulation helps forecast heavy summer rainfall and floods

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High-resolution atmospheric simulation helps forecast heavy summer rainfall and floods

Science and Technology Daily News (Reporter Wu Changfeng) The reporter learned from the University of Science and Technology of China on July 28 that the atmospheric environment numerical simulation laboratory led by Professor Zhao Chun of the school used the global variable resolution atmospheric model (MPAS-Atmosphere) to analyze the East China region. The study on the diurnal variation of precipitation in the Meiyu season revealed that the global variable resolution model encryption to the convective resolution scale can significantly improve the ability to simulate the diurnal variation of precipitation in the Meiyu season in East China, and clarified the diurnal variation of precipitation under the control of different atmospheric circulation situations in the Meiyu season. mechanism. The research results were recently published in the internationally renowned academic journal “Journal of Geophysical Research: Atmosphere” in the field of atmospheric sciences.

In the past 2020, my country’s Yangtze River Basin experienced super violent plums, and the direct economic loss in Anhui Province alone reached 59.16 billion yuan. Therefore, a better understanding of the Meiyu precipitation mechanism is of great significance to precipitation forecasting and disaster warning. The diurnal variation of precipitation is an important criterion for evaluating cumulus and other parameterization schemes in numerical models. However, due to the relatively simple criteria of convection triggering in the convection parameterization scheme, and the unconstrained entrainment of convection in the boundary layer, the convection parameterization scheme is widely regarded as one of the important sources of error in precipitation simulation. Due to the limitation of computing resources and computing efficiency, most of the current common analytical scale simulations of convection are regional models, and regional models need to be restricted by boundary conditions, which cannot well reflect the interaction between small-scale and large-scale.

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In the study, the researchers used the global variable resolution atmospheric model for the first time to simulate the diurnal variation of Meiyu precipitation in East China. This model combines the advantages of the high resolution of the regional model and the global atmospheric circulation model that does not require regional boundary conditions. The study set up a set of experiments in eastern China to encrypt to 4 kilometers, and a set of experiments with a global resolution of 60 kilometers. The results show that the two sets of experiments can better simulate the spatial distribution of precipitation in the rainy season, but the intensity and frequency of precipitation can be better reproduced by encrypting to 4 kilometers, indicating that the simulation of convective analytical scale is strong for forecasting summer discontinuity. Precipitation and floods have better indications.

At the same time, as the Meiyu season in 2015 experienced a change in the atmospheric circulation situation, the study found that during the strong Meiyu period, the daily change of precipitation showed a peak in the early morning, which was mainly controlled by the southwest wind jet at night. The simulated difference of daily precipitation changes during the period is relatively small.









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