Photochemical air pollution in highly urbanized subtropical regions

Transcription

1 Photochemical air pollution in highly urbanized subtropical regions - from micro environments to urban-terrestrial-oceanic interactions Tao WANG, Chair Professor, CEE A newly funded Theme-based project from HK Research Grants Council ( , HK$33.33M)

2 Outline 1. Motivation and Significance 2. Strategy and Scope 3. Team and Collaboration

3 Severe Air Pollution in China Photochemical smog Haze (fine particles) May 4, 2017 January 5, 2017 May 10, 2017 上海 Beijing Guangzhou Hong Kong 3

4 Health Impact of Air Pollution Premature deaths Worldwide : 7 million/yr China: 1.03 million/yr (WHO, 2015) Hong Kong: 3,200/yr o 160,000 hospital bed days o 40 billion HK$ economic loss per year 4

5 Mitigation of air pollution is top priority of mainland and HK Governments National People s Congress in March 2017 China's Premier Li Keqiang vows to tackle chronic air pollution. China will fight a Blue Sky Battle. It is a priority of this Government to reduce air pollution and the associated risks to people s health. - C Y Leung, Chief Executive of HKSAR 5

6 Complex Sources and Formation of Air Pollution Photochemical oxidation CO NO x SO 2 VOCs Particles Radicals Other Oxidants O 3 Fine particles (PM 2.5 ) Primary emission Secondary formation 6 Ocean Ocean Urban Urban Terrestrial Terrestrial Key Radicals: OH, HO 2, RO 2, NO 3, Cl 6

7 Air pollution control in Hong Kong Step-by-step measures taken on major sources since 1980s. - SO 2 - PM - since 1980s Industry - fuel change Road Transport - emissionreduction devices - green diesel - tightened standards - Since 2000s Power Plants VOCs - SO 2 - PM - NO x - since 1990s - architectural paints -coatings Marine Vessels - SO 2 - PM -printing inks -consumer products -Since 2000s - NO x - Low sulfur fuel since 2014

8 Ineffective for photochemical pollution Emissions of NOx and VOC have been reduced NO x -1.6% yr -1 VOC -3.35% yr -1 Ambient Ambient O 3 and roadside NO 2 have not decreased Data source: HKEPD 8

9 Problem in Previous Approach - Need a urban-terrestrial-oceanic paradigm O 3 Particles NaCl Halogens AVOC PM CO SO 2 NO x BVOC HONO 9 Ocean Ocean Urban Urban Terrestrial Terrestrial 9

10 Problem in Previous Approach - Need a urban-terrestrial-oceanic paradigm O 3 Particles NaCl Halogens AVOC PM CO SO 2 NO x BVOC HONO 10 Ocean Ocean Urban Urban Terrestrial Terrestrial 10

11 Problem in Previous Approach Need to consider roadside & regional pollution Regional O 3 OH NO NO 2 HONO Local Dynamics + Chemistry? Roadside pollution 11

12 Mission and Goals To understand complex multi-scale processes of photochemical pollution in subtropical high-density urban areas and recommend evidence-based mitigation strategies. 12

13 Overall Strategy Core 5: Assessment of impacts and mitigation of Photochemical Pollution Core 3: Radical chemistry and photochemical oxidation Core 4: Micro- to meso- scale Processes Core 2: Reactive chlorine and oceanic emissions Urban Emissions Core 1: Terrestrial / Biogenic emissions 13 Ocean Ocean Urban Urban Terrestrial 13

14 Core area 1: Terrestrial/Biogenic Emissions Biogenic VOCs emission factors Soil HONO emission fluxes MEGAN-China biogenic emission model Enclosure measurement Control unit Pump MEGAN-China Chamber HONO/NO/N 2 O Gas Analyzer Unit Soil samples Soil emission fluxes Canopy measurement 14

15 Core area 2: Reactive Chlorine Sources Sea salt aerosol (SSA) emission o Parameterization in air quality models Anthropogenic chlorine emission Combustion of domestic coal biomass wastes Thermal Power Plant Chlorine emission measurement 15

16 Core area 3: Radical Chemistry and Photochemical Oxidation OH radical measurement technique Comprehensive field observations o Concurrent measurements of precursors, radicals, intermediates and secondary products o Regional air quality + Meteorology + Satellite Chamber simulation o Focus on new radicals (NO 3, Cl) Observation-based photo-chemical model simulations 16

17 Core area 4: Micro- to Meso-scale Processes Large-eddy Simulation (LES)- Chemistry coupled model o Roadside to urban process Street canyon WRF-Chem-UCM-LES model and multi-scale air quality prediction Prevailing wind doped O 3 NO plume iso-suface NO 2 production on the plume o Regional and local interactions 17

18 Core area 5: Mitigation of Photochemical Pollution Transfer scientific research results into policy making New Tools & Knowledge - Improved emission data - New knowledge on radical chemistry, SOA, etc. - Improved air quality modelling tools Evaluate Current Policies - HK Clean Air Plan - HK Air Quality Objectives Review - HK Plan - Guangdong Clean Air Plan Amend Objectives - Specific emission sources and pollutants to be controlled - Health and Climate impacts - New town planning and re-development of urbanized areas 18

19 Prof. Tao Wang Atmospheric observation and chemical processes Prof. Xinming Wang Anthropogenic and biogenic VOCs Dr. Chun-Ho Liu Atmospheric turbulence Dr. Peter Louie Emission and policy Prof. Guy Brasseur Climate and air quality modelling A multi-disciplinary team 7 Co-PIs from 4 HK Universities 2 Co-PIs from mainland and Europe 1 Co-PI and Co-I from Gov. Dr. Kin-fai Ho Air pollution effect on human health Prof. Alexis Lau Air quality modelling Prof. Hai Guo VOC chemistry and modelling Prof. Shun-chen Lee Emission and aerosol measurements Dr. Zhe Wang Organic aerosol measurements 19

20 Prof. Alex Guenther (UC Irvine) Biogenic emission Prof. Daniel Jacob (Harvard) Global air quality model Prof. Allen Goldstein (UC Berkeley) Organic gases and aerosols characterization Prof. Donald Blake (UC Irvine) Atmospheric chemistry and VOC measurement Collaborators and Advisors from U.S and Mainland China A multi-disciplinary team 7 Co-PIs from 4 HK Universities 2 Co-PIs from mainland and Europe 1 Co-PI and Co-I from Gov. Prof. Yuanhang Zhang (Peking U) Academician China air quality research and policy Prof. Steven Brown (NOAA) Radical and oxidation chemistry World-leading atmospheric scientists Prof. Gregory Carmichael (U Iowa) Air quality model development Prof. Junyu Zheng (Jinan U) PRD regional anthropogenic emission Dr. Yingjun Liu (UC Berkeley) Organic aerosols and VOC oxidation Prof. Liuju Zhong (Jinan U) PRD air quality and policy 20

21 Project Governance Collaborators and Advisors from U.S and Mainland China Management Committee A multi-disciplinary team 7 Co-PIs from 4 HK Universities 2 Co-PIs from mainland and Europe 1 Co-PI and Co-I from Gov. Scientific Advisory Committee Stakeholders Advisory Committee Government Industrial sectors Public 21

22 Potential collaboration with the Industry Urban design improving air flow in the city Road transport traffic management and new vehicle (e.g. electric vehicle) Marine vessels further reduce emissions and relocate port Energy Increase in renewable energy and natural gas PRD pollution sources 22

23 Bring back the blue sky! Thank You!