Assimilation of wind profiler observations and its impact on three-dimensional transport of ozone over the Southeast Korean Peninsula

In order to investigate the impact of data assimilation on the assessment of ozone concentration in inland regions in the eastern area of the Korean Peninsula, several numerical experiments have been carried out using the Weather Research and Forecasting (WRF) model to estimate atmospheric circulations and the Community Multiscale Air Quality (CMAQ) model to assess air quality. Observations of wind that are assimilated into the modeling system are obtained from a wind profiler located at Changwon (CW), which is an urbanized coastal region in the Korean Peninsula. mulated wind and temperature that is related to a well-developed sea breeze circulation are more consistent with observations in the experiment with dada assimilation than that without the assimilation. The ozone concentrations at both the coastal area of CW and the inland region of DG are well reproduced in the simulation with application of profiler data assimilation. Results from experiments without data assimilation are less realistic than that from the experiment with data assimilation. r, the improvement in simulation of meteorological variables and ozone concentration due to data assimilation is greater in the inland area than in the coastal area, where the wind profiler is located. The ozone concentration in CW changes only over a limited area and below the altitude of 1 km with a maximum change of 25 ppb. In contrast, the simulated ozone concentration in DG has been improved from the ground to upper levels of the planetary boundary layer (PBL), despite the fact that the observations are collected and assimilated into the model at the coastal region. Based on the results of process analysis, we find that the horizontal and vertical transportation of ozone related to the sea-breeze is more important than the local contribution of chemical production in determining the ozone concentration over the inland area. Therefore, observations of wind profiles in the coastal area and assimilation of these observations into the modeling system are important in our modeling study to assess the ozone concentration in inland areas. The assimilation of observations can greatly improve the model performance in both circulation simulation and ozone concentration simulation.