Characteristics of Air Pollutant Distribution and Sources in the East China Sea and the Yellow Sea in Spring Based on Multiple Observation Methods

Abstract

The composition of marine aerosol is quite complex, and its sources are diverse. Across the East China Sea (ECS) and the Yellow Sea (YS), multi-dimensional analysis of marine aerosols was conducted. The characteristics of carbonaceous aerosols and gaseous pollutants were explored through in situ ship-based observation, MERRA-2 reanalysis datasets and TROPOMI data from Sentinel-5P satellite. Black carbon (BC)’s average concentration is 1.35 ± 0.78 μg/m3, with high-value BC observed during the cruise. Through HYSPLIT trajectory analysis, sources of BC were from the northern Eurasian continent, the Shandong Peninsula, the ECS and Northwest Pacific Ocean (NWPO). The transport of marine sources like ship emissions cannot be ignored. According to the absorption Angstrom exponent (AAE), BC originates from biomass burning (BB) in the shortwave band (~370 nm) and from fossil fuel combustion in the longwave band (~660 nm). Organic carbon (OC), sulfate (SO42−) and BC report higher Angstrom exponent (AE) while dust and sea salt reveal lower AE, which can be utilized to classify the aerosols as being fine- or coarse-mode, respectively. OC has the highest AE (ECS: 1.98, YS: 2.01), indicating that anthropogenic activities could be a significant source. The process of biomass burning aerosol (BBA) mixed with sea salt could contribute to the decline in BBA’s AE. Ship emissions may affect the distribution of tropospheric nitrogen dioxide (NO2) in the ECS, especially during the COVID-19 pandemic. Tropospheric NO2 over the YS has the highest value (up to 12 × 1015 molec/cm2). Stratospheric NO2 has a ladder-like distribution from north to south, and the variation gradient was lower than that in the troposphere. Carbon monoxide (CO) accumulates in the south and east of the ECS and the east of the YS, while the variation over the eastern YS is relatively frequent. Seas near the Korean Peninsula have extremely high CO concentration (up to 1.35 × 1017 molec/cm2).

The formation and transport of HNO3 over the Yellow Sea and its impact on the January 2018 PM2.5 episode in Seoul

“…Significant advances in understanding toward long-range transport and formation of PM 2.5 have been made in East Asia in the recent decade, but limited research has been conducted on the impact of the Yellow Sea on PM 2.5 events in western Korea, with a significant lack of observational data. More recently, ship-based observations, 10,11 satellite data analysis, 11 and monitoring in islands off the west coast of Korea 9 have been made to measure PM 2.5 and criteria air pollutant concentrations over the Yellow Sea. However, monitoring of gaseous precursors of PM 2.5 including NH 3 gas HNO 3 over the Yellow Sea is still lacking and recommended as a future study.…”

“…However, HNO 3 measurement and analysis were rarely conducted in previous studies of the Yellow Sea. [9][10][11] The goal of the present work is to evaluate the contribution of HNO 3 production over the Yellow Sea to the PM 2.5 concentration in the western coastal cities of Korea during a multi-day PM 2.5 episode. The WRF-CMAQ model was employed to model the transport/chemistry/dry deposition with a focus on HNO 3 formation over the Yellow Sea.…”

Estimation of Daily Seamless PM2.5 Concentrations with Climate Feature in Hubei Province, China

“…Air pollution, chiefly from PM 2.5 (particulate matter with a diameter of 2.5 microns or less), presents a significant health hazard [1], causing respiratory illnesses [2], cardiovascular complications [3], and even premature mortality [4]. Various methods, ranging from ground-based monitoring stations [5] to numerical simulations [6] and satellite remote sensing [7], have been utilized over recent decades to collect PM 2.5 data. Ground-based stations, while precise, are spatially sparse and unevenly distributed.…”