The impacts of dust aerosol and convective available potential energy on precipitation vertical structure in eastern China as seen from multiple source observations

Abstract. The potential impacts of dust aerosol and atmospheric convective available potential energy (CAPE) on the vertical development of precipitating clouds in eastern China were studied using multiple-sources observations. In the study area, heavy dusty condition is coupled with strong north wind which carried airmass contained high concentration of mineral dust particles with cold temperature and strong wind shear. This leads to weaker CAPE in dusty days comparing with that in pristine days. Based on satellite observations, the precipitating drops under dusty condition grow faster at middle layer (with temperature -5 °C to +2 °C) but slower at upper and lower layer comparing with the pristine counterpart. For a given precipitation top height, the precipitation rate under dusty condition is weaker in upper layer but heavier at middle and lower layer. And the associated latent heating rate released by precipitation at middle layer is stronger. The precipitation top temperature (PTT) shows fairly good linear relationship with near surface rain rate (NSRR). The linear regression slope between PTT and NSRR are stable at dusty and pristine conditions. However, the PTT₀ (precipitation top temperature related to rain onset) at the onset of rain are highly affected by both CAPE and aerosol condition. In pristine days, stronger CAPE facilitate the vertical development of precipitation and leads to a decrease of PTT₀ at the rate of -0.65 °C per 100 J kg^-1 CAPE for deep convective precipitation with variation of 15 %, and by -0.41 °C per 100 J kg^-1 CAPE for stratiform precipitation with variation of 12 %. After removing the impacts of CAPE on PTT, dust aerosols lead an increase of PTT at the rate by +4.19 °C per unit AOD for deep convective precipitation and by +0.35 °C per unit AOD for stratiform precipitation. This study showed clear evidence that meteorology conditions are combined with aerosol condition together to affect the vertical development of precipitation clouds. And quantitative estimation of the sensitivity of PTT to CAPE and dust were provided.