报告时间：2016年11月17日（周四）下午4:00
报告地点：卫津路校区第八会议室
Professor Alastair C
Lewis, Wolfson
Atmospheric Chemistry Laboratories, University of York, York, United
Kingdom http://www.york.ac.uk/chemistry/staff/academic/h-n/alewis/
报告摘要：
Air pollution has been an environmental problem for many hundreds of years and
the first laws to control air pollution were introduced more than 700 years ago
in the UK. Despite continued investment in emission reduction technologies many
areas in Europe continue to suffer from air pollution that is above both
European and WHO guidelines.
This presentation will review the progress that has been made in reducing
certain pollutants and the new challenges that have arisen associated with
expansion of the diesel vehicle fleet.
Observations of the emissions of NO2 from a variety of experiment methods
including tall tower fluxes, aircraft eddy covariance and tailpipe remote
sensing have been used to identify the scale of NOx emissions in London.
Total London emissions of NOx are typically two times higher than are currently
reported in the national emissions inventory. Testing of more than 100,000 different
vehicles shows however that individual emissions from EUROIV and EUROV vehicles
can be as much as 6 times higher than estimates based on
rolling-road tests. Understanding the exact geographic distribution of
different vehicle types in London is however central to creating effective
control policies.
A secondary consequence of increases in the European diesel vehicle fleet has
been an increase in the total emissions of volatile organic compounds (VOCs).
Using novel multidimensional chromatography methods we demonstrate that the
distribution of VOCs has shifted from smaller hydrocarbon compounds to longer
chain hydrocarbons >C9. The impacts of this change in speciation of VOCs
will be discussed both in terms of urban atmospheric reactivity and the formation
of secondary organic aerosols. A potential policy consequence of this shift to
diesel (with enhanced higher carbon number VOCs emitted) is that some European
countries may find it challenging to meet their 2020 commitments for limiting
emissions under the Gothenburg protocol.
