Multi-resolution Emission Inventory for China (MEIC):

Transcription

1 Multi-resolution Emission Inventory for China (MEIC): Introduction and recent improvement Liu Yan Tsinghua University

2 Contents Introduction What is MEIC? How does it work? Review of spatial proxies What are used in China? Recent improvements High resolution inventories?

3 Introduction: Purpose of MEIC model Understand magnitudes, trends, and driving forces of anthropogenic emissions in China Speed up the development process and update inventories timely Provide an online emissions dataset to the community with constant methodology and underlying data Support climate and air quality modeling at different spatial resolution and time scale

4 Introduction: Emissions data in MEIC database l Years: l Spatial domain: Mainland China l Categories/Sectors: ~800 anthropogenic sources, aggregated to four sectors (Power, Industry, Residential, Transportation) l Species: SO2, NOx, CO, NMVOC, NH3, BC, OC, PM2.5, PM10, and CO2 l VOC speciation: ~600 individual species, lumped to five mechanisms (SAPRC99, SAPRC07, CB05, CBIV, and RADM2) l Spatial resolution: user defined Work in progress!

5 Introduction: Model Framework Temporal profiles Spatial Proxies VOC profiles Removal Efficiency (ƞ) ID1 ID2 ID3 ID4 Activity rates (A) Emission Factors (EF) Tech. Splits (X) ID1: sectors ID2: fuel/product ID3: technology ID4: emission control Emissions = A X EF (1-ƞ)

6 Introduction: Emission estimation & Spatial proxies Sectors Emission estimation Spatial proxies Power Unit based No need Point sources Industry Population Province GDP Transportation Residential Province based to county County to grid Road network Vehicle numbers Surface sources

7 OMI proved the decreases of SO 2 over Central Eastern China after 2007 Emissions OMI

8 Trend in NO x emissions from MEIC and NO 2 columns from satellite

9 Emissions data processed and delivered through an online system

10 Review: Spatial proxies used in China Review of the spatial proxies used in regional bottom-up emission inventories covering China Population (especially total population) is most widely used proxies.

11 Review: Spatial proxies used in China Population density polluted factories distribution: opposite! Beijing Zhangjiakou Shijiazhuang Tangshan

12 Review: Spatial proxies used in China Spatial proxies used in MEIC

13 Recent Improvement: High resolution inventories Emissions of main sub-sectors in industry sector are estimated based on facility. More point sources! Eg.Steel production process Coal Ore Coke Coke oven Sinter/Pellet Coke E = A EF 1 η ik, i ik, ink,, Power generation Coal n fired boiler EF = A ( 1 ar ) f PM Coke oven gas 2 ( ) ( ) EF = 2 S 1 sr SO EF = EF f OC PM OC EF = EF f BC PM 2.5 BC PM 2.5 Blast furnace gas * * ( ) ( 1 n ) E = A EF + A EF η n Gas fired machine Sintering machine Blast furnace Converter * * = ( + ) ( 1 n ) E A EF A EF η n ( ) ( ) EF = 2 S 1 sr * * * EF = 2 S 1 sr Pig iron Crude steel Steel rolling Material/fuel Dischargingpoint Intermediate product Finalproduct

14 Recent Improvement: High resolution inventories Emissions of main sub-sectors in industry sector are estimated based on facility. More point sources! Power: SO 2 Power: NO X Steel: SO 2 Cement: NO X Building material: PM 2.5 Industry boiler: SO 2

15 Recent Improvement: High resolution inventories Emissions of main sub-sectors in industry sector are estimated based on facility. More point sources! NO Emission estimation X emission spatial distribution (High resolution-regional) (a) MEIC (b) High-resolution MEIC: overestimate in urban, underestimate in rural 15

16 Recent Improvement: High resolution inventories On-road emissions of transportation sector are estimated at county level. Altitude Temperature Humidity Eg. Environmental compensation factors matrix are built at county level, which can improve the spatial and temporal precision

17 Recent Improvement: High resolution inventories On-road emissions of transportation sector are estimated at county level. Spatial proxies Activity at county level Road network Compensation factors Emission factor Emission standards

18 Recent Improvement: High-resolution inventories Spatial proxies used in MEIC and our new high-resolution inventory for Hebei province, 2013(HB-EI)

19 Recent Improvement: High-resolution inventories Spatial correlations between gridded emissions of HB-EI and various spatial proxies. NL: nighttime light TP: total population UP: urban population RP: rural population RN: road network

20 Recent Improvement: High resolution inventories Evaluations against in situ measurementsfor atmospheric modeling (CMAQ) using MEIC and HB-EI Resolution: 36km(region scale) 4km(city scale), the simulation bias with regional inventory increases, but decreases with high resolution inventory. At 4km, using high resolution inventory can can shorten the PM 2.5 simulation bias from31% to -2%;O 3 from -17% to - 9% PM 2.5 O 3 Regional inventory PM 2.5 Observation O 3 Observation High-resolution inventory

21 Thanks for your attention!