time series of satellite-based fine particulate matter (pm 2.5 ) concentrations over china:...
TRANSCRIPT
Time series of satellite-based fine particulate matter (PM2.5) concentrations
over China: 2004-2012
Guannan Geng, Qiang Zhang, Aaron van Donkelaar, Randall V. Martin, and Kebin He
2013-12-11, San Francisco
Sources and negative effects of fine particles (PM2.5)
ClimateBrown CloudAcid rainHazeHealth
Increased morbidity and mortality from bothacute and chronic exposure to ambient fineparticulate matter (PM2.5)
fine particulate matters in the (ambient) air with 2.5 micrometers or less in size
Regional haze is a major concern in China
Beijing haze
Primary pollutants in 74 cities
(2013.1-10)
PM2.5 concentration
(2013.1-10)
Heavy PM2.5 pollution occurs in China, especially in the North China Plain
How has PM2.5 evolved over the past decade over China?
• Long-term variation of PM2.5 concentrations is important for epidemiological studies.
• China has developed control strategies for the precursors of PM2.5, e.g. SO2 and NOx.
• But ground measurements are limited in China– Only several research groups have monitored the ground level
PM2.5 concentration before the year 2013.
– National network of PM2.5 monitoring is built up since 2013.
Satellite Remote sensing approach can be used to enhance our ability to estimate PM2.5 concentration
• Many works have used aerosol optical depth (AOD) to retrieve PM2.5 concentration
• In this study, ground-level PM2.5 concentrations for the period 2004-2012 over China are estimated using CTM to provide the conversion factor between PM2.5 and AOD.
𝑷𝑴𝟐 .𝟓= 𝒇 (𝑨𝑶𝑫 )Multiple linear regression
Chemical transport model
Satellite-derived surface PM2.5
van Donkelaar et al, EHP, 2010van Donkelaar et al, JGR, 2013
𝑨𝑶𝑫 𝒔𝒂𝒕𝒆𝒍𝒍𝒊𝒕𝒆×𝑷𝑴𝟐 .𝟓𝒎𝒐𝒅𝒆𝒍𝒆𝒅
𝑨𝑶𝑫𝒎𝒐𝒅𝒆𝒍𝒆𝒅
GEOS-Chem (GC)
𝑷𝑴𝟐 .𝟓𝒔𝒂𝒕𝒆𝒍𝒍𝒊𝒕𝒆
PM2.5 AOD
MISR CALIPSO
AODVertical Profile
emissionsMEIC
Emission trends of the precursors in China
• The MEIC inventory, 2004-2012
Evaluation of model simulationsSNA simulation in the year of 2006
Modeled AOD trend compared with MISR
Slope = 0.28, R = 0.32Slope = 0.26, R = 0.33Slope = 0.19, R = 0.17Slope = 0.85, R = 0.39
Slope = 0.44, R = 0.81Slope = 0.52, R = 0.78Slope = 0.68, R = 0.71Slope = 0.86, R = 0.88
Slope = 0.58, R = 0.66Slope = 0.79, R = 0.82Slope = 0.64, R = 0.49Slope = 0.93, R = 0.74
Satellite-based PM2.5 retrieved from MISR AOD
Trends of the conversion factor and MISR AOD
Modeled PM2.5 Modeled PM2.5/AOD
MISR AOD
Modeled AOD
The population weighted national annual mean PM2.5 trends over China during 2004-2012
104
PM2.5 trends of some cities in China
The effect of the correlation slope between modeled and satellite AOD on PM2.5 trend
Conclusions
• National scale surface PM2.5 concentration derived from MISR
increased from 2004 to 2006 and started to decrease around 2006-2007, and had a second small peak in 2011. The trend between 2004 and 2012 was +0.5 ug·m-3·yr-1.
• In the Northern China, there are mostly increasing trends, even above 4 ug·m-3·yr-1 in some regions. While in the Southern China, PM2.5 decreased in 2012 compared to 2004.
• PM2.5 concentrations in some megacities have started to decrease
slightly.
Thank you!