Transboundary aerosol transport process and its impact on aerosol-radiation-cloud feedbacks in springtime over Northeast Asia

Abstract

Northeast Asia has been suffering from dramatic increases of particulate matter (PM) since the late 1990s, and it still continues to undergo haze despite various abating regulations. In this study, we investigated aerosol-cloud-precipitation (ACP) interactions with the varied PM, and the impact of long-range transport (LRT) process on ACP in springtime was assessed in Northeast Asia. Our long-term (1995–2019) analysis of PM10 exhibited the correlation with decreases of both sunshine duration and drizzle occurrences that can be interpreted as direct and indirect aerosol effects, while cloud cover induced by the varied PM10 was found only in more than 90% cloud cover (9/10–10/10 category). The online WRF-Chem with wind-blown dust simulation indicated that cloud water was affected by secondary inorganic aerosol (SIA) formation near the surface in upwind areas dominantly, whereas, along the LRT pathway, cloud water perturbation altitudes were increased quasi-linearly toward downward between 1 and 3 km. The gas-to-particle conversion ratios of sulfur ([SO42−]/[SO2 + SO42−]) and nitrogen ([NO3−]/[NO2 + NO3−]) both remain aloft long at the same vertical levels of most perturbed cloud altitude enough to be transported over long distance in springtime. Formations of sulfate and nitrate showed different ACP interaction timing; distinctive shifts in the ratios observed at the exit (Shanghai-Yellow Sea) by nitrate, and entrance areas (Seoul-Tokyo) by sulfate along the LRT pathway, respectively, with higher ratios of 0.8 or more in springtime. Our results indicate that ACP processes have been enhanced at a LRT-related altitude with different SIA production timings that can be considered in species-specific springtime PM abatements over Northeast Asia.

GNU Data Language 1.0: a free/libre and open-source drop-in replacement for IDL/PV-WAVE

“…Interactive Data Language (IDL) is a commercial, domain-specific language used for processing data in various scientific fields, including astronomy, geosciences, biology, hyperspectral, medical imaging (Burrage et al, 2021;Castro-Tirado et al, 2021;Coates et al, 2019;Lee et al, 2022;Xiao et al, 2022), and even COVID-19 research (Chen et al, 2021). Although IDL is not so widely used these days for scientific computing with the rise of modern computing languages, many legacy IDL codes are still being used.…”

Optical Properties of Boundary Layer Aerosols From High Spectral Resolution Lidar Measurements in a Polluted Urban Environment (Seoul, Korea)

“…Therefore, long‐term regional aerosol measurement studies within East Asia and its downwind regions are essential for a better understanding of the relationship between air pollution and local health impacts (Shiraiwa et al., 2017). In addition, understanding the characteristics of aerosols and their temporal variation in polluted urban regions is important for setting regulatory programs and improving the simulation of aerosols for public forecasting (Lee et al., 2022; H. Kim et al., 2018; Y. Kim et al., 2018; Schutgens et al., 2016).…”

Transported aerosols regulate the pre-monsoon rainfall over north-east India: a WRF-Chem modelling study

“…The effects differ spatially depending on the constituents of aerosols, their physical and chemical properties, and the quantity. Among these factors, atmospheric transport also plays an important role, which extends the climatic impacts to the transported region from the source region (Lee et al, 2022). The IGP is a global hotspot of diverse aerosols (Ojha et al, 2020;Kumar et al, 2018) that impacts regional and global climate (Ramanathan et al, 2005;Tri-pathi et al, 2005;Sarangi et al, 2015).…”