Long-term characteristics of hydrometeors in stratiform and convective precipitation over central eastern China and adjacent ocean

Based on the fifth generation atmospheric reanalysis (ERA5) hourly data from May to August during 1979-2020, the long-term features of four hydrometeors (cloud water, cloud ice, rain, and snow) in stratiform and convective precipitation over the central eastern China and its adjacent northwest Pacific Ocean, as well as their relationship with precipitation intensity were first investigated. Results show that the ERA5 hydrometeor data is generally reasonable over the study regions by comparing with 7-yr GPM retrievals. In stratiform precipitation, the cloud water profile presents a double-peak structure over land and ocean. The distribution of precipitation intensity is in agreement with that of cloud ice path, indicating that stratiform precipitation is more dominated by ice processes, and the deposition latent heating is the main heat source. In convective precipitation, the rain water mixing ratio is distinctly greater over ocean than that over land due to the higher conversion rate from cloud droplets to raindrops, along with abundant snow water there. The pattern of convective precipitation intensity is more consistent with that of rain water path, and the ice-phase hydrometeor path is 1-2 times that of liquid phase hydrometeor, suggesting a comparable contribution of water and ice processes. The condensation latent heating with its upward transport is the main heat source in convection. It's found that the conversion rate from rain water to surface rainfall is higher in convective than in stratiform regimes, and is faster over land than over ocean, which should be attributed to the larger-size raindrops in the former. In addition, the continental precipitation diurnal circle exhibits a bimodal structure, while the oceanic precipitation has only a single peak. The peaks of ice-phase hydrometeors lag behind the peak of precipitation in the afternoon owing to the different moisture dynamic structures.

Automated summary

Based on ERA5 data, this study analyzed the characteristics of four hydrometeors and their relationship with precipitation intensity in central eastern China and the northwest Pacific Ocean. The results show that stratiform precipitation is dominated by ice processes, while convective precipitation has comparable contributions from water and ice processes.