Northeast summer precipitation multi-mode combined downscaling prediction method

Abstract

Aiming at improving the prediction accuracy of the summer precipitation in northeast China and further improving the climate service capacity, the northeast summer precipitation multi-mode combined downscaling prediction method is developed. The method takes advanced climate mode forecast information and early stage actual condition factor information both at home and abroad into consideration, combines a mode error correction technology, and adopts a singular value decomposition method to respectively establish a coupling type relation between a small-scale northeast summer precipitation field, a large-scale mode summer circulation forecast field and a large-scale early stage external forced actual condition field, thereby establishing a northeast summer precipitation forecast model. Theoptimal northeast summer precipitation multi-mode combined downscaling forecasting model with regional characteristics is obtained through the comparison and inspection of multi-mode and multi-schemeforecasting effects. The northeast summer precipitation multi-mode combined downscaling prediction method can effectively improve the northeast summer precipitation prediction accuracy rate of climatemodes both at home and abroad, and better provide technical support for government disaster prevention and reduction decisions.

Description

technical field [0001] The invention belongs to the field of climate prediction, and in particular relates to a multi-model combined downscaling prediction method for summer precipitation in Northeast China. Background technique [0002] Monthly and seasonal (especially in summer and each month) climate trend prediction has always been the focus and difficulty of short-term climate prediction, and it is also an important reference for the government's flood control and drought relief work deployment. For decades, meteorologists have done a lot of work to improve the accuracy of climate prediction and achieved many meaningful results. [0003] At present, there are two main ideas for short-term climate prediction. One is a statistical method that relies on historical data to analyze evolution laws, and the other is a dynamic method that relies on physical mechanisms to establish numerical models. Both methods have their own advantages and disadvantages. own flaws. Chou Jifa...

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Problems solved by technology

[0004] By summarizing the previous studies, it is found that: firstly, the former National People’s Congress forecast the summer precipitation in Northeast China as a whole, but the impact factors of early summer and midsummer are different, so it is necessary to carry out downscaling prediction work to distinguish between early summer and midsummer precipitation; secondly, in the process of downscaling prediction , often purely based on the atmospheric circulation information with high model prediction skills, and the uncorrected model circulation field output results are often directly used when establishing the downscaling relationship, while taking into account the corrected model circulation prediction information and external forcing information. The downscaling and forecasting of precipitation combinations in early summer and midsummer in Northeast China is even rarer; finally, most of the interpretation and application of models are based on a single model, and the work of multi-model integrated forecasting effects and comparison of single-model skills is slightly less

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