Marine aerosol distributions from shipborne observations over the South China Sea: diurnal variation characteristics and their controlling factors
Year: 2025
Type: article
Abstract: . Marine aerosols critically influence Earth's radiation budget and climate dynamics through their spatial distributions and components due to their generation and transport processes. However, in-situ observational datasets remain limited, particularly in the South China Sea (SCS). Based on our comprehensive shipborne measurements, this study presents a quantitative analysis of marine aerosol distributions and compositional variations between the offshore and pelagic environments over the SCS. Our data demonstrate a 120 % elevation in offshore aerosol number concentrations (NCs, 0.5–10 μm) relative to pelagic baselines, featuring 120 % higher accumulation-mode particles (0.5–2 μm) and 70 % higher coarse-mode particles (2–10 μm), quantitatively confirming continental transport affects offshore aerosol signatures. In contrast, in the pelagic areas, marine aerosols are virtually unaffected by continental transport and distinctly represent characteristics of the local generation. Meteorological analyses identified wind speed (WS) and sea surface temperature (SST) as primary regulators of NC. However, observed NC variations at fixed WS and SST values suggest additional controlling factors. We demonstrate that sea-air temperature differences (SST-T2m) exhibit a stronger correlation (r = −0.82, p<0.01) with NC than the other meteorological parameters, where increased SST-T2m corresponded to decreased marine aerosol production. This temperature gradient effect drives pronounced diurnal NC variations, with maximum differences of 35 % observed between daytime, nighttime, and transition periods. These results prove the key explanations for the variations of spatial and diurnal distributions of marine aerosols to understand marine aerosol generation and transport better.
Authors: Zhi Qiao, Shengcheng Cui, Huiqiang Xu, Xiaoqing Wu, Xiaodan Liu, Zihan Zhang, Mengying Zhai, Yue Pan, Tao Luo, Xuebin Li
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,725
Awards: G3952839068, G529649520, G8953765373
OpenAlex ID: W4417266447