Corrigendum to "A novel downscaling technique for the linkage of global and regional air quality modeling" published in Atmos. Chem. Phys., 9, 9169–9185, 2009

摘要

Recently, downscaling global atmospheric model outputs (GCTM) for the USEPACommunity Multiscale Air Quality (CMAQ) Initial (IC) and Boundary Conditions(BC) have become practical because of the rapid growth of computationaltechnologies that allow global simulations to be completed within areasonable time. The traditional method of generating IC/BC by profile datahas lost its advocates due to the weakness of the limited horizontal andvertical variations found on the gridded boundary layers. Theoretically,high quality GCTM IC/BC should yield a better result in CMAQ. Unfortunately,several researchers have found that the outputs from GCTM IC/BC are notnecessarily better than profile IC/BC due to the excessive transport ofO₃ aloft in GCTM IC/BC. In this paper, we intend to investigate theeffects of using profile IC/BC and global atmospheric model data. Inaddition, we are suggesting a novel approach to resolve the existing issuein downscaling.In the study, we utilized the GEOS-Chem model outputs to generatetime-varied and layer-varied IC/BC for year 2002 with the implementation oftropopause determining algorithm in the downscaling process (i.e., based onchemical (O₃) tropopause definition). The comparison between theimplemented tropopause approach and the profile IC/BC approach is performedto demonstrate improvement of considering tropopause. It is observed thatwithout using tropopause information in the downscaling process, unrealisticO₃ concentrations are created at the upper layers of IC/BC. Thisphenomenon has caused over-prediction of surface O₃ in CMAQ. Inaddition, the amount of over-prediction is greatly affected by temperatureand latitudinal location of the study domain. With the implementation of thealgorithm, we have successfully resolved the incompatibility issues in thevertical layer structure between global and regional chemistry models toyield better surface O₃ predictions than profile IC/BC for both summerand winter conditions. At the same time, it improved the vertical O₃distribution of CMAQ outputs. It is strongly recommended that the tropopauseinformation should be incorporated into any two-way coupled global andregional models, where the tropospheric regional model is used, to solve thevertical incompatibility that exists between global and regional models.We have discovered that the previously published paper wasnot the latest version of the manuscript we intended to use.Some corrections made during the second ACPD reviewingprocess were not incorporated in the text. As a result, thefigure numbers (i.e., figure number below the graph) werenot referenced correctly in the manuscript. Therefore, wehave decided to re-publish this paper as a corrigendum.