THE REGENTS PARK AND TOWER ENVIRONMENTAL EXPERIMENT

REPARTEE 2006 & 2007

Roy M. HarrisonUniversity of Birmingham

PARTICIPANTS IN REPARTEEInstitution Role

University of Birmingham Project management

Soluble ions

ATOFMS

NO, NO2, O3, SMPS

University of Manchester Aerosol fluxes

HR-AMS

Centre for Ecology & Hydrology, Particle fluxes

Edinburgh & Lancaster UniversityGas fluxes (PTR-MS)

Particle and gas chemistry

AMS

Kings College, London Electron microscopy of particles

University of Cambridge NO3 and N2O5 measurement

University of Reading & Meteorological measurements including

University of Salford Doppler Lidar

University of Bristol Field dispersion of inert tracer

REPARTEEOBJECTIVES OF REPARTEE

• To study aerosol chemical and dynamical processes within the atmosphere of central London in three spatial dimensions.

• To measure the fluxes of selected aerosol and gas phase species above the city, and where possible to compare fluxes with estimates derived from emissions inventories. In this context, the work was coordinated with that on the CityFlux project in which fluxes were determined over a number of UK cities.

• To quantify gradients in selected aerosol and trace gas species from ground-level to altitudes of sampling on the BT tower and to use such information to better understand the respective roles of local emissions, local transformations and regional transport of pollutants in influencing the composition within and above London.

REPARTEEOBJECTIVES OF REPARTEE – cont’d

•To study the structure of the atmospheric boundary layer and the influence of boundary layer vertical structure upon trace gas and aerosol fluxes and air pollution processes.

•To deploy purposeful tracer releases at ground level while monitoring at the surface and aloft in order to evaluate the dispersion of trace gases released at low level within the city.

•To determine spatial differences in aerosol particle size distributions and to interpret those differences in terms of the sources and physico-chemical transformations responsible.

•To study the properties of nitrate aerosol in the atmosphere of London, together with mechanisms of formation, physico-chemical properties and dynamics of nitrate particles.

•To throw new light on the source apportionment of PM1, PM2.5 and

PM10 in the atmosphere of London.

THE SAMPLING SITES

Map of Central London

Meteorological instrumentsand fast response pollutionsensors

Height of most instruments

BT TOWER

REGENTS PARK FROM THE TOWER

MARYLEBONE ROAD

NORTH KENSINGTON

• Universities Facilities for Atmospheric Measurement (UFAM) 1.5 micron scanning Doppler lidar (Halo-photonics)• 24th Oct to 14th Nov 2007 • vertical stare• 30 m resolution gates• integration every 4 sec

• backscatter• along beam Doppler velocity (vertical component)

Doppler Lidar Measurements

Mass and Major Component Chemical Data

REPARTEE DATES

REPARTEE I27 Sept-23 Oct 2006

REPARTEE II 16 Oct – 11 Nov 2007

Air masses during REPARTEE I

Mainly maritime, except

11-12 Oct : arrives over France

14-17 Oct : from Poland over near continent

Mass closure for PM2.5 at Regents Park

y = 0.9481x

R2 = 0.9668

y = 0.843x + 1.4199

R2 = 0.988

0.00

5.00

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Gravimetric mass concentration (µg/m3)

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cted

mas

s co

nce

ntr

atio

n (

µg

/m3)

Regents Park

Linear (Regents Park)

Linear (Regents Park)

DATA FROM THE AEROSOL TIME-OF-FLIGHT MASS

SPECTROMETER

AND

AEROSOL MASS SPECTROMETER

5

4

3

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1

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AM

S m

ass

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ug

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)

06/10/2006 11/10/2006 16/10/2006 21/10/2006

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AMS_Nitrate ATOFMS_nitrate

Time series of AMS nitrate and ATOFMS nitrate particle count, London, 2006

Time series of two nitrate particle types, London, 2006

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06/10/2006 11/10/2006 16/10/2006 21/10/2006

ATOFMS_nitrate Nitrate_type_1 Nitrate_type_2

Mass spectra of two nitrate particle types measured in London, 2006

m/z

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n in

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sity

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Nitrate_type 1

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39

97

62

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y0 10 20 30 40 50 60 70 80 90 100

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48Nitrate_type 2

36

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48 6039

9746

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12

Time series demonstrating the semi-volatility of type 2 nitrate

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00:0014/10/2006

12:00 00:0015/10/2006

12:00 00:0016/10/2006

12:00 00:0017/10/2006

12:00 00:0018/10/2006

12:00

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cou

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e 2 co

re)

Nitrate_type_1 Nitrate_type_2 'Nitrate_type 2 core'

Particle Size Distributions – SMPS data

Conclusions• The experiments have proved powerful in identifying

spatial patterns in pollutant concentrations and size distributions, and in elucidating atmospheric physico-chemical processes.

• Work on vertical gradients has been especially informative.

• Particle size distributions are highly dynamic and site-dependent.

• There are many other aspects to the experiment which my colleagues will report upon.

ACKNOWLEDGEMENTSFunding:

National Environment Research Council and the BOC Foundation.

Science Contributions:Dr Manuel Dall’OstoMr Alistair ThorpeDr David BeddowsNumerous collaborators from other

institutes