A Study on the Wet Scavenging Characteristics of Atmospheric Aerosol in the Korean Peninsula Using NAMIS (National Ambient Air Quality Monitoring Information System) Data and Its Application to Air Quality Modeling System

Abstract

Wet scavenging is one of the main mechanisms for the removal of particulate matter in the atmosphere. In this respect, precipitation is an important component and plays a key role in the removal of air pollutants. When precipitation occurs, raindrops fall, inducing below cloud scavenging, absorbing pollutants and removing them from the atmosphere. The wet scavenging process is affected by the strength, duration, concentration, and distribution of air pollutants. The aerosol wet scavenging coefficient ( Λ m ) by precipitation is used to formulate a change in aerosol concentration ( C ) during the precipitation time ( t ). According to the equation, the wet scavenging coefficient was calculated using multi-year PM 2.5 hourly concentration data from the NAMIS (National Ambient air quality Monitoring Information System). The main purpose of this study is to gain a better understanding of scavenging coefficients including characteristics unique to Korea by using measurement data for five years for 12 cities. By applying a developed scavenging coefficient to the three-dimensional air quality model, these results provide wider support for improving the accuracy of simulating particle matters in East Asia. An implication of the new scavenging coefficient is a value that better reflects precipitation characteristics in Korea and one that can also help research scavenging characteristics in East Asia in the future and contribute to improving modeling accuracy.