Simulating Performance of CHIMERE on a Late Autumnal Dust Storm over Northern China

Abstract

The accurate forecasting of dust emission and transport is a societal demand worldwide as dust pollution is part of many health, economic, and environment issues, which significantly impact sustainable development. The dust forecasting ability of present air quality forecast systems is mainly focused on spring dust events in East Asia, but further improvement may be needed as there is still difficulty in forecasting autumn dust activities, such as failing to predict the serious dust storm that occurred on 25 to 26 November 2018. In this study, a state-of-the-art air quality model, CHIMERE, with three coupled dust schemes was introduced for the first time to simulate the dust emissions during this event to qualitatively and quantitatively validate its dust simulating performance over Northern China. The model results reported that two of the three dust schemes were able to capture the dust emission source located in Gansu Province and reproduce the easterly dust transport path, showing moderately close agreement in the horizontal and vertical distribution patterns with the ground-based and satellite observations. The simulated PM10 concentration had a better relationship with the observed values with a correlation coefficient up to 0.96, while it was lower in the transported areas. Meanwhile, the simulations also presented incorrect dust emission positions such as in areas between the Hulun Buir sandy land and Horqin sandy land. Our results indicate that CHIMERE exhibits reasonably good performance regarding its dust simulation and forecast ability over this area, and its application would help to improve the dust analysis and forecast abilities in Northern China.

Review Comments for Zeng et al. gmd-2019-310

“…Hopefully, these issues can be easily addressed with additional plots and documentation. Papers by Ma et al (2019), Letcher and LeGrand (2018), Rizza et al (2017), and Nguyen et al (2019) offer good examples of approaches for general dust case study descriptions, forcing weather evaluations, and/or vertical dust distribution assessments.…”

Variation of Aerosol Optical Depth Measured by Sun Photometer at a Rural Site near Beijing during the 2017–2019 Period

“…It can be seen that the satellite and ground-based AOD and the ground-based AOD and PM at the national control site have similar trends, although there are some spatial location differences between the sun photometer and the national control site, and the previously discussed opposite daily trends of AOD and PM can be reflected here. PM 2.5 /PM 10 < 0.4 was defined as a dusty day [84], and this pollution event can be roughly divided into four stages in time: haze, local pollution and dust mixing, dusty backflow, and pollution transmission.…”