Sensitivity of Heavy Convective Precipitation Simulations to Changes in Land‐Atmosphere Exchange Processes Over China

Abstract

Heavy precipitation and associated flood hazards can cause enormous socioeconomic losses. The advances in atmospheric modeling enable great promise in accurately predicting precipitation. However, the representation of land‐atmosphere exchange processes in atmospheric models and its impacts on precipitation evolution remain high uncertainties. This study investigated the sensitivity of convective precipitation to land‐atmosphere exchanges and examined the improvements in precipitation simulations by a dynamic vegetation‐type‐dependent exchange scheme. We conducted 3‐km‐resolution convection‐permitting modeling for three heavy precipitation events that occurred over areas with different dominant land‐cover types. The results showed that land‐atmosphere exchange efficiency significantly altered the precipitation intensity as well as the onset and peak time of precipitation but hardly affected the precipitation pattern. Strong exchange simulations could agree better with the observed precipitation in the 21 July 2012 Beijing and the 19 June 2010 Jiangxi heavy precipitation events occurring over humid and semihumid zones, while weak exchange simulations could attain higher consistencies with the observations in the 30 July 2012 Ningxia heavy precipitation event occurring over arid and semiarid zones. As a more physical alternative, the dynamic exchange simulations could achieve the closest agreement with the field observations, especially the intensity and location of the heaviest rainfall. The dynamic scheme modifies land‐atmosphere exchange efficiency to match local land cover conditions and could provide promising applications in heavy precipitation modeling studies.

Summer Convective Precipitation Changes Over the Great Lakes Region Under a Warming Scenario

“…This finding highlights the importance of low‐level moisture for the formation of MCS precipitation, which has been also highlighted by previous studies (e.g., Peters et al., 2017; Schumacher & Peters, 2017; Yang, Varble, et al., 2023). Schumacher and Peters (2017) found that the low‐level moisture strongly regulates the amount of precipitation produced by MCSs, that is, a 3.4% increase in vertically integrated water vapor leads to an increased by nearly 60% in the area integrated MCS precipitation.…”

“…Schumacher and Peters (2017) found that the low‐level moisture strongly regulates the amount of precipitation produced by MCSs, that is, a 3.4% increase in vertically integrated water vapor leads to an increased by nearly 60% in the area integrated MCS precipitation. Given the importance of low‐level moisture in conditioning the thermodynamic environment (Schumacher & Peters, 2017; Yang, Varble, et al., 2023), vertical profiles of RH are shown in Figure 9. For places where MCS or IDC are increased (1st and 3rd column), the RH profiles of PGW simulations are very similar to or slightly smaller than that of the baseline simulations.…”

Understanding Precipitation Moisture Sources and Their Dominant Factors During Droughts in the Vietnamese Mekong Delta

“…Yang et al. (2023) found that dryness was caused by the differences in horizontal wind convergence by comparing the moisture flux differences between control and experimental simulations. Similarly, Benedict et al.…”

Appropriately representing convective heating is critical for predicting catastrophic heavy rainfall in 2021 in Henan Province of China

“…Although many studies have simulated/forecasted extreme precipitation events such as the '21.7' rainstorm in Henan Province at convection-permitting scale (Zhu et al 2018, Zhao et al 2019, Luu et al 2022, Yin et al 2022, Zhang et al 2022, very few studies investigated the influence of forecasted atmospheric circulation on forecasting regional extreme precipitation events at convection-permitting resolution, particularly regarding how convective parameterization can affect forecasted extreme precipitation at convection-permitting resolution by modulating forecasted atmospheric circulation. Therefore, in this study, the '21.7' catastrophic rainstorm event of 2021 in Henan Province is investigated to reveal the impacts of forecasted atmospheric circulation modulated by convective parameterization on the regional convection-permitting forecast of this event.…”