Improved Dust Emission Reduction Factor in the ADAM2 Model Using Real-Time MODIS NDVI

Sang-Sam Lee,Yun-Kyu Lim,Jeong Hoon Cho,Sang-Boom Ryoo,Hee Choon Lee

doi:10.3390/atmos10110702

Abstract

The Korea Meteorological Administration has employed the Asian Dust Aerosol Model 2 (ADAM2) to forecast Asian dust events since 2010, where the dust emission flux is proportional to the fourth power of the friction velocity. Currently, the dust emission reduction factor (RF) is determined by the normalized difference vegetation index (NDVI). This study aims to improve the forecasting capability of ADAM2 by developing a daily dust RF using both monthly (January 2007 to December 2016) and real-time moderate resolution imaging spectroradiometer (MODIS) NDVI data. We also developed a look-up table to transform the RF using NDVI and a system to update the RF by producing MODIS NDVI data for the last 30 days. Using these data, new RFs can be produced every day. To examine the impact of RF modification, the current (CTL) and new (EXP) RFs are compared during the period from March to May 2017. The simulations are verified by ground-based PM10 observations from China and Korea. Accordingly, root mean square errors (RMSEs) are reduced by 11.58% when RF is updated using real-time NDVI data. The results suggest that recent daily NDVI data contribute positively to the forecasting ability of ADAM2, in the dust source and downwind regions.

Highlights

In arid and semi-arid regions in East Asia, Asian dust has been emitted into the atmosphere over a long period of time
The simulated data were compared with ground-based PM10 observation data from 27 Korea Meteorological Administration (KMA) sites, sites, 15 China Meteorological Administration (CMA)
The Asian Dust Aerosol Model 2 (ADAM2) Asian dust forecasting model has been operated by the KMA since 2010

Summary

Introduction

In arid and semi-arid regions in East Asia, Asian dust has been emitted into the atmosphere over a long period of time. Asian dust emission is high in spring, but has more recently been observed in autumn and winter as well [1]. In addition to socio-economic effects, the dust impacts human health; causing, for example, reduced lifespans, respiratory illnesses, eye diseases, etc. In recent decades, the expansion of arid regions in eastern Mongolia and Manchuria has increased the frequency of dust events in downwind regions such as Korea and Japan [7,8]. It is becoming increasingly important to accurately predict dust concentrations in order to mitigate the associated hazards. The Korea Meteorological Administration (KMA) has operated the Asian Dust Aerosol Model

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Conclusion