Modeling the distribution and increase of oak pollen over the Seoul metropolitan region

Abstract

Introduction: Numerical modeling techniques could enhance our understanding about exposure assessment for allergic pollen. This study aims to understand the spatiotemporal distribution and increase of oak pollen associated with transport and dispersion over the Seoul metropolitan region (SMR) in Korea using Community Multi-scale Air Quality (CMAQ) model. Methods: A 10 day-run for oak pollen simulation was conducted during high oak pollen periods in 2014 using CMAQ pollen modeling system. This system consists of Weather Research and Forecast (WRF) model and CMAQ linked with Oak Pollen Emission Model (OPEM). Oak pollen inventories were calculated by OPEM which uses as inputs the meteorological parameters (temperature, wind speed, relative humidity, and vertical turbulence velocity) produced by WRF model, measured pollen counts, and the oak tree coverage data from Forest Geographic Information System. Results: The simulated temporal variation of the oak pollen concentrations reasonably followed the measured concentration from the Burkard sampling stations in the SMR. The spatial distribution of pollen was closely associated with some meteorological conditions allowing to transport and accumulation. In particular, in urban area early in the morning on 19 April, high concentration of oak pollen was related with wind flow and lower-atmospheric structure in the planetary boundary layer. Conclusions: Our results revealed that the spatiotemporal distribution and increase of oak pollen were significantly associated with the meteorological processes and this modeling approach could be assisted to estimate population exposure to allergic pollen.