Simulation study on the indirect effect of sulfate on the summer climate over the eastern China monsoon region

Abstract

In this study, we designed a sensitivity test using the half number concentration of sulfate in the nucleation calculation process to study the aerosol-cloud interaction (ACI) of sulfate on clouds, precipitation, and monsoon intensity in the summer over the eastern China monsoon region (ECMR) with the National Center for Atmospheric Research Community Atmosphere Model version 5. Numerical experiments show that the ACI of sulfate led to an approximately 30% and 34% increase in the cloud condensation nuclei and cloud droplet number concentrations, respectively. Cloud droplet effective radius below 850 hPa decreased by approximately 4% in the southern ECMR, while the total liquid water path increased by 11%. The change in the indirect radiative forcing due to sulfate at the top of the atmosphere in the ECMR during summer was − 3.74 W·m−2. The decreased radiative forcing caused a surface cooling of 0.32 K and atmospheric cooling of approximately 0.3 K, as well as a 0.17 hPa increase in sea level pressure. These changes decreased the thermal difference between the land and sea and the gradient of the sea-land pressure, leading to a weakening in the East Asian summer monsoon (EASM) and a decrease in the total precipitation rate in the southern ECMR. The cloud lifetime effect has a relatively weaker contribution to summer precipitation, which is dominated by convection. The results show that the ACI of sulfate was one possible reason for the weakening of the EASM in the late 1970s.

Plants emit sulfate-, phosphate- and metal-containing nanoparticles

“…Using Community Atmosphere Model 3.0, some scholars found a seasonal effect of sulfate aerosols on the water cycle process (Wu and Liu, 2009). Some scholars have also noted that since the late 1970s, the increase in anthropogenic sulfate aerosols has led to the weakening of summer monsoon precipitation in East Asia (Wang et al, 2021)…”

Discovery and significance of nanoparticles released by plants

“…Using Community Atmosphere Model 3.0, some scholars found a seasonal effect of sulfate aerosols on the water cycle process (Wu and Liu, 2009). Some scholars have also noted that since the late 1970s, the increase in anthropogenic sulfate aerosols has led to the weakening of summer monsoon precipitation in East Asia (Wang et al, 2021)…”

Complex Interplay of Sulfate Aerosols and Atmospheric Dynamics on Precipitation Vertical Structure and Latent Heat in the Beijing-Tianjin-Hebei Region: A Satellite Perspective

“…The Beijing-Tianjin-Hebei (BTH) region, recognized as China's capital economic zone, is rapidly urbanizing and industrializing. Sulfate aerosol is one of the predominant summer aerosol components in the BTH region [1][2][3] . The primary source of atmospheric sulfate is the oxidation of SO2, which mainly emanates from human activities, industrial processes, and the combustion of fossil fuels 4 .…”

“…For instance,Wang et al (2021) observed sulfate aerosols acted as CCN, increasing the CCN and cloud droplet number concentrations by approximately 30% and 34%, respectively, during summer in the East Asian monsoon region. This reduced the effective radius of cloud droplets below 850 hPa by 4%, and increased the total liquid water path by 11%, which caused a decline in the radiation reaching the surface, consequently cooling the atmosphere.…”

“…This reduced the effective radius of cloud droplets below 850 hPa by 4%, and increased the total liquid water path by 11%, which caused a decline in the radiation reaching the surface, consequently cooling the atmosphere. Such changes diminished the thermal contrast between land and sea, resulting in a decreased total precipitation rate in the southern part of the East Asian monsoon region2 . Zhou et al (2017) identified that sulfate aerosols in the North China Plain and the Tibetan Plateau increased cloud droplet number concentrations, reduced cloud droplet size, inhibited the warm rain process, and transported more cloud droplets above the 0°C isotherm.…”