JpGU-AGU Joint Meeting 2020

講演情報

[E] ポスター発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS11] Aerosol impacts on air quality, climate system, and our society

コンビーナ:安成 哲平(北海道大学 北極域研究センター)、Kyu-Myong Kim(NASA Goddard Space Flight Center)、Hongbin Yu(NASA Goddard Space Flight Center)、竹村 俊彦(九州大学応用力学研究所)

[AAS11-P09] Regional trends of combustion aerosol and dust in recent decades: a satellite-model integrated analysis

*Hongbin Yu1Yang Yang2Hailong Wang1Qian Tan3,4Mian Chin1Robert Levy1Lorraine Remer5Steven Smith2Tianle Yuan1,5Yingxi Shi1,5Zhibo Zhang5Qianqian Song5Paul Ginoux6 (1.NASA Goddard Space Flight Center、2.Pacific Northwest National Laboratory、3.Bay Area Environmental Research Institute、4.NASA Ames Research Center、5.University oof Maryland Baltimore County、6.NOAA GFDL)

キーワード:pollution, dust, satellite, model, trend

Emissions and long-range transport of mineral dust and combustion-related aerosol from burning fossil fuels and biomass vary from year to year, driven by the evolution of the economy and changes in meteorological conditions and environmental regulations. This study offers both satellite and model perspectives of interannual variability and possible trends of combustion aerosol and dust in major continental outflow regions over the past 15 years (2003-2017). The decade-long record of aerosol optical depth (AOD, denoted as t), separately for combustion aerosol (tc) and dust (td), is derived from the aerosol products of the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard both Terra and Aqua. The MODIS datasets, complemented by aerosol source-tagged simulations using the Community Atmospheric Model Version 5 (CAM5), are then analyzed to understand the interannual variability and potential trend of tc and td in the major continental outflows. Both MODIS and CAM5 consistently yield a similar decreasing trend of -0.017 to -0.020 per decade for tc over the North Atlantic Ocean and the Mediterranean Sea that is attributable to reduced emissions from North America and Europe, respectively. On the contrary, both MODIS and CAM5 display an increasing trend of +0.017 to +0.036 per decade for tc over the tropical Indian Ocean, the Bay of Bengal, and the Arabian Sea, which reflects the influence of increased anthropogenic emissions from South Asia and the Middle East in the last 2 decades. Over the northwestern Pacific Ocean that is often affected by East Asian emissions of pollution and dust, the MODIS retrievals show non-monotonic but overall decreasing trend of -0.021 per decade for tc and -0.012 per decade for td, which is however not reproduced by the CAM5 model. In other outflow regions strongly influenced by biomass burning smoke or dust, both MODIS retrievals and CAM5 simulations show no statistically significant trends; and the MODIS observed interannual variability is usually larger than that of the CAM5 simulation. Seasonal variations of regional trends will also be discussed.