Assessment and merged optimization of multi-source winter precipitation products over northern China

Based on the data between December 2019 and February 2020, multi-source precipitation products such as CMORPH, IMERG, GSMaP satellite retrieved precipitation, quanity precipitation estimate (MOC-QPE), CMA-MESO model forecast, and grid analysis product based on gauges etc. are assessed. The statistical error indicates that the grid analysis dataset based on gauges is the best and robust among all the precipitation products. The MOC-QPE and IMERG are better in the southern area of northern China but worse in high-latitude area, especially for solid precipitation. IMERG is the best one of satellite products, while CMORPH is the worst in winter over northern China. CMA-MESO product has a high correlation with gauged observations, higher than satellite and radar products, and is valuable for merge analysis. Based on BMA method, the MOC-QPE, IMERG, and CMA-MESO are gradually added to and analyzed in merged products. Results indicate that both IMERG and CMA-MESO can improve the winter precipitation, but CMA-MESO has the largest contribution to the enhancement of the merge analysis accuracy.